INTRODUCTION, PURPOSE AND SCOPE OF THE STUDY

As part of the Counterminous United States Mineral Assess-

ment Program (CUSMAP), the United States Geological Survey found

anomalous copper in stream sediments from washes draining Black

Mountain and the Batamote Mountains, two miles south and ten miles

northeast of Ajo, Arizona, respectively. The anomalous area defined

by the values to the northeast of Ajo encompasses the northwestern

two -thirds of the Batamote range. However, the source of the values

was not determined by the U.S.G.S.

The purpose of the present study is to define, characterize

and explain this anomaly. Five mechanisms are considered to be

possible explanations of the anomaly:

1. Airborne contamination from a smelter located in Ajo;

2. Abnormally high background copper concentrations in the

volcanics composing the Batamote Mountains;

3. Primary hydrothermal mineralization within the study area;

4. Dispersion through the volcanic pile along normal

faults; and

S. Contamination of the volcanics immediately before or

during their eruption.

Each of these working hypotheses should have a unique dispersion

pattern and a characteristic partitioning of copper among mineral

phases.

1

2

The smelter is located just south of Ajo. Smelters are

known to produce anomalies in soil samples, and the wind in the area

was observed to blow southwest to northeast at times; consequently,

airborne dispersion from the smelter could produce, the observed

anomalies. Dispersion from this source would tend to have a plumose

form and decrease in intensity downwind. Any copper would be held

in glass as part of the smelter dust.

The second possible mechanism, abnormally high background

values, would be characterized by a highly uniform distribution of

high values within the stream sediments. Additionally, the source

rock unit would have to have high copper concentrations; the copper

would probably be held as a trace component within silicate minerals.

Primary hydrothermal mineralization would be characterized by

a dispersion pattern localized around the mineralization. As such,

anomalies would tend not to be very widespread. Given the aridity and

nature of weathering in the Batamote Mountains, primary copper minerals

could be preserved in sediments in addition to secondary minerals and

oxides.

Dispersion of copper along normal faults would yield broad

dispersion patterns at the surface, related spatially to the faulting.

Copper would probably be held in oxide coatings, organics or as

chrysocolla.

The final mechanism considered, contamination of the volcanics

before or during their eruption, would produce uniformly high values

in streams draining the volcanics or a zonation about the volcanic

center. If the contaminants were not assimilated, the bulk of the

3

volcanics would not contain unusual values of copper --only xeno-

lithic fragments would contain anomalous copper. However, if the

hypothesized contaminants were totally assimilated, the dispersion

would be similiar to that observed for an andesite with high back-

ground copper; therefore, this mechanism could be indistinguishable

from an andesite with high background.

Given the expected responses for the five different mechan-

isms, the purpose of this study is to define the surficial dispersion

of copper, both mineralogically and areally, within the Batamote

Mountains. This information, in combination with lithogeochemical

and geological data can then be used to infer the genesis of the

copper anomaly discovered by Barton and others (1982).

The study was conducted in three stages: 1. Resampling of

the sites found to be anomalous by Barton and others (1982); 2. High

density collection of stream sediment and heavy mineral concentrate

samples; and 3. Reconnaissance geologic mapping, rock chip sampling

and resampling the anomalies found in the second step. Field and

analytical work was performed between December, 1982 and February,

1984.

LOCATION, PHYSIOGRAPHY AND CLIMATE

The study was conducted in the Batamote Mountains which are

within the Basin and Range Province of southwestern Arizona- -five to

ten airmiles (8 to 16 km) northeast of Ajo in Pima County. Ajo is

the site of Phelps Dodge's New Cornelia porphyry copper deposit and

the previously mentioned smelter. Figure 1 shows the location of

the thesis area in relation to Ajo, Phoenix, and Tucson. The study

area lies almost entirely within the Ajo and Sikort Chuapo 15-

minute U.S.G.S. quadrangles.

The mountains trend west -northwesterly and have a length

of twelve miles (19 km) and a width of up to five miles (8 km).

Maximum elevation is 3202 feet (972 m) with relief of up to 1700

feet (520 m). Physiographically, the mountains occur as relatively

low plateaus surrounding a high central peak that has the appear-

ance of a dissected stratovolcano (see Figure 2). However, the

preserved surface of the peak is not depositional (Gilluly, 1946).

The mountains have relatively youthful drainages which are charac-

terized by narrow canyons with moderate to steep gradients (Gilluly,

1937) .

The area around Ajo receives an average of nine inches of

precipitation annually, with the rainiest months being July and

August (NOAA, 1981). Temperatures range from 30 °F to 120 °F (0 °C

to 50 °C) with temperatures in excess of 100 °F (38 °C) common from

4

S

May to September. Consequently, drainages in the area consist of dry

washes. Field observations indicate that the wind often blows from

the southwest to the northeast, creating a potential for airborne

smelter contamination in the study area.

GILA BEND

AJO

LUKEVILLE r TUCSON

Figure 1 -- Location of study area

6

10 MILES

N

100 MILES

/

Figure 2 -- Photograph, looking east, of the high point, Batamote

Mountains

PREVIOUS WORK

Previous work on the geology, surficial geochemistry and

geophysics of the Batamote Mountains is contained within reports

encompassing larger or nearby areas. Early work in the area began

with Joralemon's report in 1914. The most recent report was pre-

pared in 1984 by Harris. Existing literature pertaining to the

geology, geochemistry and geophysics of the area is reviewed in

this section.

Geology

Joralemon (1914) discussed the history and economic geology

of the Ajo district. DeKalb (1918) and Ingham and Barr (1932) dis-

cussed the same topics, but they also concentrated on the mining

methods employed at the New Cornelia Mine. These three papers refer

only briefly to the geology outside the immediate Ajo district.

Bryan (1928) described the physiography and geology of the

Batamote Mountains in general terms. Additionally, he described

the log of a well located one mile west of the mountains. Through

1936 this is the only paper that described the geology of the area

of interest.

In 1935, Gilluly published the first of four papers that

are probably the best work on the geology of the Ajo area. In

this paper Gilluly described the history and geology of the Ajo

mining district. However, in papers published in 1937. 1942 and

8

9

1946, Gilluly discussed the geology and physiography of the Ajo 15-

minute quadrangle in addition to the district geology. These papers

contain excellent descriptions of the geology, lithology and physi-

ography of the western half of the Batamote Mountains.

Following the last Gilluly paper, there was a long hiatus

on publications relating to the Ajo area. Dixon (1966) and Wadsworth

(1968) described the geology of the New Cornelia Mine and Cornelia

pluton, respectively. Jones (1974) discussed the geology of the

Ajo Range, south of the study area.

The most recent publication covering the Batamote Mountain

area is a compilation of the geology of the Ajo 1 °by 2°quadrangle

by Kahle and others (1978). As this is part of CUSMAP, more litera-

ture should be forthcoming from this group.

The geology of the Hat Mountain and Sikort Chuapo 15- minute

quadrangles has been mapped and reports are in preparation as part

of a cooperative study between the U.S. Geological Survey and the

Bureau of Indian Affairs on the geology and mineral resources of

the Papago Indian Reservation (Haxel and others, 1980).

Surf icial Geochemistry

Also as part of CUSMAP, the U.S. Geological Survey conducted

a reconnaissance exploration geochemistry study over the Ajo 1° by 2°

quadrangle (Barton and others, 1982). Anomalies discovered as part

of this project served as the impetus for the present study. Most

recently, Theobald and Barton (1983) discussed the statistical

10

relationships within the U.S.G.S. data. More literature should come

out of this group in the future.

Geophysics

Finally, Klein (1983) published a residual aeromagnetic map

of the Ajo and Lukeville 1° by 2° quadrangles. Raines and Theobald

(1981) are conducting remote sensing studies in the Ajo 1° by 2° quad-

rangle. Again, future papers should be forthcoming about the geo-

physics of the area.

REGIONAL GEOLOGY

The regional geology of the Ajo area is described in excel-

lent detail by Gilluly (1946). This section is largely based on

that work. For further discussion, the reader is referred to this

and other papers by Gilluly (1937 and 1942).

The Ajo and Sikort Chuapo 15- minute quadrangles consist

mainly of Tertiary volcanics and Quaternary alluvium. Pre -Cenozoic

rocks crop out dominantly in the Little Ajo Mountains and the Chico

Shunie Hills, west of the town of Ajo. Figure 3, based on Gilluly

(1946), gives the stratigraphy of the Ajo 15- minute quadrangle and

can be inferred to represent the general stratigraphy of the entire

area. Figure 4 is a regional geologic map of these two quadrangles

based on Wilson and others (1969).

Stratigraphy

The oldest unit in the area is the Precambrian Cardigan Gneiss.

The unit has a wide variety of rock types within it, ranging from

gneisses through schists with minor pegmatites. This unit has been

intruded throughout by small bodies of Precambrian hornblendite

that show chilled contacts against the gneiss. The Cardigan Gneiss

crops out principally in the Gibson Arroyo, west of Ajo.

According to Gilluly (1946), the only Paleozoic rock present

in the region is hornfelsic sandstone, shale and volcanics occuring

as xenoliths in the Chico Shunie Quartz Monzonite, which crops out

11

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Unit

16 Alluvium

Unconformity

1Older Alluvium

Unconformity

15 Batamote Andesíte--intrusive facies

14 Batamote Andesite--extrusive

13 Batamote Andesite--vent facies

Unconformity

12 2Childs Latite11 Daniels Conglomerate

Unconformity

10 2Sneed Andesite

Unconformíty

9 2Aj o Volcanics8 Locomotive Fanglomerate

Unconformity

1Felsic to intermediateplugs, sills and dikes

7 Cornelia Quartz Monzo-nite (main facies)

6 Cornelia Quartz Monzo-nite (dioritic facies)

5 Concentrator Volcanics

Unconformity

4 Chico Shunie QuartzMonzonite

3 Hornfels

Unconformity

2 Hornblendite1 Cardigan Gneiss

ZUnit from Wilson and others, 1969The Childs Latite, Sneed Andesite and AjoVolcanics were combined in Wilson and others,.1969

12

Age Symbol

Quaternary Qa

Plio -Pleis- QTatocene

Miocene

Miocene Tba

Miocene

MioceneMiocene

Miocene

MioceneMiocene

Tertiary/CretaceousTertiary/CretaceousTertiary/CretaceousCretaceous

TvTps

Tv

TvTms

TKi

TKg

Mesozoic Mzgr

Paleozoic

PrecambrianpCgnPrecambrian

Figure 3-- Stratigraphy of the Ajo area (after Billuly, 1946)

TE

A

B R

TA

MO

TE

MOUNTRItJS

CO

FFE

EPO

TM

OU

NT

AIN

Tho

Qa

P69"

5 M

Is.E

SS

cALt

: o:2

5q00

0

Figure 4-- Simplified geologic map of the Ajo and Sikort Chuapo 15- minute quadrangles, Arizona (after

Wilson and others, 1969).

See Figure 3 and text for description of units.

14

extensively in the southwestern part of the region. This unit has a

highly variable texture and composition, but the predominant variety

is a coarsely porphyritic quartz monzonite.

Unconformably overlying the basement, the Cretaceous Concen-

trator Volcanics crop out one to two miles south of Ajo. This forma-

tion consists of andesitic tuffs, flows and breccias that have been

extensively altered.

No pre- Tertiary rocks crop out in the Sikort Chuapo quad-

rangle (Wilson and others, 1969).

The Laramide Cornelia pluton intrudes the Concentrator Vol -

canics, Cardigan Gneiss and Chico Shunie Quartz Monzonite over much

of the Little Ajo Mountains, several miles west of the town of Ajo.

The pluton is composed of a wide range of distinct facies, many of

which show gradational contacts. Two units have been separated out

by Gilluly (1946), a border quartz diorite facies, located in the

western part of the intrusive, and a quartz monzonite facies. These

two units show a sharp contact. As the description of these rocks

is not the thrust of this discussion, the reader is referred to

papers by Dixon (1966) and Wadsworth (1968) in addition to the papers

by Gilluly and a thesis by Harris (1984) for a more detailed descrip-

tion of these units.

The New Cornelia orebody, which was originally the cupola of

the Cornelia pluton (Wadsworth, 1968) has been downfaulted several

thousand feet by the Gibson fault; it lies south of the town of Ajo

and southeast of the main pluton. Through 1962 two million tons of

copper had been recovered from 255 million tons of ore and 270 million

15

tons of waste (Dixon, 1966). Recently, after a short shutdown caused

by the depressed price of copper, Phelps Dodge reopened the New

Cornelia Mine. The smelter was built in 1950 and is currently not

operating.

Unconformably overlying the Cardigan Gneiss, the Concentrator

Volcanics and the Cornelia Quartz Monzonite in pediments and slopes

to the southeast of the Little Ajo Mountains, the Middle Tertiary

Locomotive Fanglomerate consists of clasts of widely varying compo-

sition and grain size. Boulders up to two feet in diameter are

common, although the average size of the fragments is less than one

inch. The quality of bedding and degree of sorting increase to the

southeast.

The Middle Tertiary Ajo Volcanics, located west and southwest

of the Ajo Peaks, conformably overlie the Locomotive Fanglomerate and

consist of andesitic breccias, flows and tuffs. The Middle Tertiary

Sneed Hornblende Andesite conformably overlies the Ajo Volcanics in

the southern part of the Childs Mountain, four miles northwest of

Ajo, and in Copper Canyon in the western part of the Little Ajo

Mountains. Unconformably overlying the Sneed andesite, the Middle

Tertiary Daniels Conglomerate crops out along the southern flanks of

both Childs Mountain and the Chico Shunie Hills. The unit consists of

alternating pebbly and sandy layers, with boulders up to four feet

in diameter.

As the two youngest bedrock units in the area are the only

bedrock in the study area, they will be described in much detail

in the following chapter. Their regional distribution in the Ajo

16

and Sikort Chuapo 15- minute quadrangles will be discussed in this

section. The only information available to the author on the Sikort

Chuapo quadrangle comes from a geologic map of the State of Arizona

(Wilson and others, 1969). Owing to the scale of the map, many

Tertiary volcanic units were not distinguished according to their

relative ages and compositions.

The Miocene Childs Latite crops out extensively throughout

southwestern Arizona. In the Ajo 15- minute quadrangle, the unit

crops out on the western side of Childs Mountain and as a small

patch in the north -central Batamote Mountains. Within the Sikort

Chuapo quadrangle, intermediate "Pliocene" volcanics (probably the

Childs Latite or its equivalent) compose the eastern part of the

Batamote Mountains, the Pozo Redondo Mountains, south of the Bata-

mote Mountains, and the western part of the Sikort Chuapo Mountains,

east of the Batamote Mountains (Wilson and others, 1969).

The Miocene Batamote Andesite, which was split into three

facies -- extrusive, intrusive and vent --by Gilluly (1946) crops out

extensively in the Batamote Mountains and on Childs Mountain. It

also crops out in the south -central part of the Ajo 15- minute quad-

rangle and in Black Mountain, four miles south -southeast of Ajo.

The extrusive facies is by far the most abundant. Outcrops of

vent breccias and the intrusive occur in the northeast part of

Childs Mountain and the central part of the Batamote Mountains; they

probably represent vents from which the Batamote andesite was ex-

truded. In the Sikort Chuapo quadrangle, "Plio -Pleistocene" basaltic

volcanics (probably the Batamote Andesite) crop out in the eastern

17

part of the Sikort Chuapo Mountains and around Coffeepot Mountain in

the northeastern section of the quadrangle (Wilson and others, 1969).

Two units of alluvium are present within the area. Plio -

Pleistocene alluvium crops out in several places in the Sikort

Chuapo quadrangle (Wilson and others, 1969). Quaternary alluvium

fills valleys and occurs as active stream deposits.

Structure

The oldest unit in the area, the Cardigan Gneiss, has undergone

several phases of deformation, the first of which probably occured in

the Precambrian. The Chico Shunie Quartz Monzonite intruded during

the Mesozoic; both the Cardigan Gneiss and the Chico Shunie Quartz

Monzonite show cataclastic deformation inferred by Gilluly (1946)

to be Mesozoic in age.

The pre- Tertiary rocks were intruded by the New Cornelia

stock in early Tertiary time (Dixon, 1966). Other Tertiary structure

in the Ajo area is characterized by normal faulting, some of which

is probably related to basin and range tectonism. The Little Ajo

Mountains are bounded on the northeast and east by the Little Ajo

Mountain and Black Mountain faults, respectively. The Childs

Mountain fault partially bounds Childs Mountain and the Little Ajo

Mountains on the west. The Gibson fault has dropped the New Cor-

nelia orebody relative to the quartz monzonite stock. Other faults

within the Little Ajo Mountains include the Chico Shunie and Ajo

Peak faults ( Gilluly, 1946).

18

The Batamote Mountains have been broken by a northerly to

northeasterly trending set of normal faults in the northwest part

of the range. These will be discussed in the next chapter in more

detail. Tertiary faulting in the Sikort Chuapo quadrangle includes

northerly to northwesterly trending normal faults in the Pozo Redondo

and Sikort Chuapo Mountains (Wilson and others, 1969).

The only folding present in the area is gentle warping in the

northern part of the Batamote Mountains (Gilluly, 1946).

In summary, the most important structural features present in

the region, relative to the problem being addressed, are Tertiary

normal faults. Motion began before the Miocene with early movement

on the Gibson fault and continued into the Holocene.

LOCAL GEOLOGY

The study area was mapped at a reconnaissance scale using

aerial photos. The results were then compared with earlier maps by

Gilluly (1937 and 1946) and Wilson and others (1969). Additionally,

contacts and faults were field checked as much as possible. Two

distinct bedrock units were recognized, the Childs Latite and the

Batamote Andesite, as named by Gilluly (1946). The Batamote Andesite

has been subdivided into three subunits -- extrusive, intrusive and

vent facies. Two units of alluvium were observed: an older unit that

forms low, sinuous hills in the north and dissected pediments in

the south, and a younger unit that fills the valleys as active

alluvium. The stratigraphy and structure of the immediate thesis

area are described in this chapter.

Stratigraphy

The oldest unit in the thesis area is the Miocene Childs

Latite with an age between 17 and 20 million years (May and others,

1980). Disconformably overlying the Childs Latite, the Batamote

Andesite also has a Miocene age of 15.52 ±0.54 million years (Shafi-

qullah and others, 1980). The two units of alluvium post -date the

Batamote Andesite. The distribution, physiography and petrography

of these units are described below.

19

20

Childs Latite

Distribution and Physiography. Within the study area, the

majority of the Childs Latite occurs toward the eastern edge. Small

patches occur in the north -central part and the northwestern part of

the area. The morthwestern patch is the southeasternmost extension

of the Crater Range.

The Childs Latite tends to form rounded to pointed hills in

the study area; however, on the western flanks of the Sikort Chuapo

Mountains, the unit tends to form prominent cliffs. In general, this

unit weathers to colors ranging from white to maroon.

Petrology and Mineralogy. In hand specimen, the Childs Latite

is typically holocrystalline and porphyritic -aphanitic, with white,

glassy, subhedral, medium to coarse grained feldspar phenocrysts in a

pink to maroon, aphanitic groundmass. However, the grain size and de-

velopment of crystal faces of the phenocrysts varies widely from out-

crop to outcrop; in some instances, the feldspar phenocrysts are anhedral

and fine grained. The unit, in general, shows excellent flow banding.

In addition to the extrusive porphyry, the Childs Latite

contains small outcrops of dikes and breccia. The dikes have the

same general texture as the extrusive unit, but they are character-

ized by discordant attitudes relative to the subhorizontal dip of

the unit. The breccia, which weathers from brown to yellowish

white, consists of coarse to very coarse (0.5 to 50 cm) blocks in a

slightly vesicular, aphanitic matrix. The blocks are composed of

flow banded, porphyritic -aphanitic Childs Latite. The breccia crops

out in the northeast in a geographical embayment of latite into the

21

Figure 5 -- Photomicrograph of Childs Latite (under crossed polars).

Note zoned plagioclase and augite phenocrysts (135 X).

22

Batamote Andesite. In the same area, stratigraphically below the

breccia, the latite has been extensively argillized.

In thin section, the latite shows the same textural vari-

ability seen in the hand specimens. The typical texture is holo-

crystalline, porphyritic -cryptocrystalline to microcrystalline, with

very fine to coarse grained anhedral to subhedral phenocrysts in a

felted cryptocrystalline to microcrystalline groundmass. The

phenocrysts, which comprise 40 to 60 volume percent of the rock, are

dominated by andesine and /or labradorite (An to An ) with lesser40 60

orthoclase, magnetite and augite. The plagioclase phenocrysts show

marked zoning, with calcic cores that have been locally argillized

to montmorillonite. Some sections contain partially resorbed,

zoned sanidine and minor biotite. The groundmass, when its com-

position is distinguishable, consists of plagioclase, augite and

magnetite. Figúre 5 shows the typical microscopic textures and

mineral compositions of the Childs Latite.

Batamote Andesíte-- Extrusive Facies

Distribution and Physiography. The Batamote Basaltic Andesite

is the most widespread unit in the study area, and it crops out over

most of the Batamote Mountains. The extrusive facies makes up the bulk

of the outcrop and forms mesas that have been extensively dissected

by deep canyons. This facies, in general, dips away from a central

plug located near the high point of the range. This is interpreted

as the volcanic vent.

23

Petrology and Mineralogy. The extrusive facies of the Batamote

Andesite occurs dominantly in flows which range in thickness up to 20

meters. The flows show a strong textural zonation, grading from a

basal gray, fissile rock of aphanitic texture, through an inter-

mediate black, massive, aphanitic section, and finally into a black,

or yellow, while the intermediate and upper units weather maroon or

scoriaceous cap. The basal unit of a flow typically weathers maroon or

black. Some sections show flow banding. Secondary minerals include

zeolites filling amygdules and chalcedony along joints and fractures.

This unit also includes minor volcanic breccia and volcano -

clastics. The volcanic breccia, which is probably a result of flow

brecciation, consists of blocks up to 50 cm in a medium to coarse

grained matrix. The volcanoclastics consist of a medium to coarse

grained, poorly sorted, poorly consolidated wacke. The minor

lithologies are not described microscopically.

The three textural zones characteristic of the flows are dis-

tinctive under the petrographic microscope. The basal zone is typically

flow banded, holocrystalline and porphyritic -microcrystalline, with fine

grained subhedral to euhedral plagioclase and olivine phenocrysts in a

felted, pilotaxitic microcrystalline groundmass consisting of plagio-

clase laths. Some sections had glass in the groundmass.

The intermediate zone is characteristically hypocrystalline,

porphyritic -microcrystalline or vitric, with fine grained, subhedral

mafic phenocrysts in a pilotaxitic, microcrystalline plagioclase

groundmass or a black hyaloophitic groundmass of microcrystalline

plagioclase laths and glass.

24

Finally, the upper zone is scoriaceous, hypocrystalline,

porphyritic - vitric with one or two sizes of phenocrysts in a vitric

groundmass. The larger phenocrysts consist of fine grained subhedral

to euhedral olivine crystals, whereas the smaller phenocrysts are

typically plagioclase microlites. Figures 6 and 7 show typical

textures and mineralogies of the basal and upper zones of the flows.

Although the texture varies widely within the flows, the

mineralogy remains relatively constant. The coarsest phenocrysts in

all thin sections are olivine grains that have been partially to

completely replaced by iddingsite. Plagioclase occurs both as

phenocrysts and microlites within the groundmasses. It has composi-

tions ranging from sodic andesine (An ) to calcic labradorite36

(An ); more typical anorthite contents range from 45 to 60 %.

Magnetite is a common accessory mineral, while hypersthene and augite

occur infrequently.

Batamote Andesite- -Vent Facies

Distribution and Physiography. The vent facies of the Bata -

mote Andesite occurs in the central part of the study area just

southwest of the high point of the Batamote Mountains. This facies

crops out on the periphery of, or stratigraphically above, the intru-

sive facies. The unit forms outcrops that stand out relative to the

surrounding rocks.

Petrology. The vent facies is a red to maroon oxidized

volcanic breccia that consists of blocks ranging in size from 10 cm

to 1 m in an aphanitic to coarse grained matrix. The easternmost

25

Figure 6 -- Photomicrograph of the basal section of a typical flow,Batamote Andesite (under crossed polars). Note plagioclase and

olivine phenocrysts in felted, pilotaxitic microcrystallinegroundmass (135 X).

26

Figure 7-- Photomicrograph of the upper unit of a typical flow,Batamote Andesite (under crossed polars). Note two sizes of pheno-

crysts in hyaloophitic groundmass (135 X)..

27

outcrop has a sub -horizontal, sedimentary -like bedding up to 2 m

thick. This facies was not described microscopically.

Batamote Andesite -- Intrusive Facies

Distribution and Physiography. The intrusive facies of the

Batamote Andesite crops out in a one square mile area in the central

part of the study area southwest of the high point of the range.

The facies has no distinctive topographic expression.

Petrology and Mineralogy. The Batamote intrusive can be

subdivided into two distinct units, a fine grained, equigranular

diorite (or gabbro ?) in the south and a dense, massive porphyritic-

aphanitic basaltic andesite in the north. The nature of the con-

tact between the two phases was not determined.

In hand specimen, the diorite is holocrystalline, hypidiomor-

phic- granular, fine grained with a salt and pepper texture. In out-

crop, the unit, which weathers gray to reddish -yellow, is massive

towards the center and grades outwards into an outer zone that is

highly jointed.

In thin section, the diorite has a grain size ranging from

0.3 to 1 mm. It is dominated by andesine (An to An ) with40 50

accessory olivine (that has been altered extensively to iddingsíte),

magnetite and minor intergranular augite and hypersthene. The

olivine /iddingstie crystals have a slightly larger grain size than

the other crystals. Figure 8 shows the textures and mineralogy of

this unit.

28

The porphyritic -aphanitic unit, which composes the bulk of

the intrusive, weathers yellow on outcrop. Towards the center of the

intrusive, the phase develops two roughly perpendicular sets of

vertical joints. Towards the edges, this jointing is less well

developed. At the edges, the unit interfingers extensively, or

grades into, the vent facies described earlier.

This unit is holocrystalline, porphyritic- cryptocrystalline

to microcrystalline, with subhedral to euhedral fine grained

(0.3 to 1 mm) phenocrysts in a cryptocrystalline to microcrystalline

groundmass. The phenocrysts are composed of olivine that has been

altered slightly to iddingsite; the groundmass, when distinguishable,

consists of andesine to labradorite (An to An ) with lesser hypers-45 60

thene, magnetite and augite. In this unit, the hypersthene predomin-

ates over the augite, whereas in the dioritic unit, augite predomin-

ates over hypersthene. Figure 9 shows the textures and mineralogy

of this phase of the intrusive.

In summary, the intrusive facies of the Batamote Andesite has

two distinct units: a diorite and a basaltic andesite. The rela-

tionship between the two units was not determined.

Older Alluvium

This alluvium, which is younger than the Batamote Andesite,

consists of pebbles and cobbles in an unconsolidated fine sand to

silt matrix. In the northwest, the unit forms low (3 m), sinuous

hills on the outwash plain north of the Batamote Mountains; the

pebbles and cobbles are composed of Batamote Andesite. On the other

29

Figure 8 -- Photomicrograph of the dioritic unit of the intrusivefacies of the Batamote Andesite (under crossed polars). Note therelative coarse granularity of the unit (135 X).

30

Figure 9-- Photomicrograph of the porphyritic unit of the intrusivefacies of the Batamote Andesite (under crossed polars) (135 X),

31

hand, in the southeast, the unit forms a dissected pediment and the

pebbles and cobbles consist of Childs Latite.

Quaternary Alluvium

The valleys and active stream channels are filled with an

unconsolidated gravel with cobbles and pebbles in a sandy to silty

matrix. In places, the alluvium has been cemented by extensive

caliche.

Structure

Deformation within the study area is limited to normal

faults in the Batamote Andesite and minor warping of both the Childs

Latite and the Batamote Andesite. Since there are no marker beds

in the study area, the structure in the area is largely conjectural,

and is based on topography and aerial photographs.

Faulting

The only faults present are located in the northwest.

Although inferred from aerial photographs, they agree well with

those reported by Gilluly (1946). Additionally, fault gouge was

observed along one fault trace. However, due to the lack of marker

beds, the displacement of the faults could not be determined. The

fault as shown by Wilson and others (1969) to pass through the center

of the range, was not observed in the field.

Folding

Gilluly (1946) reports relatively minor warps within the

Batamote Andesite; however, the majority of the attitudes in this

32

unit are depositional. During reconnaissance mapping, an anticline

was observed in the Childs Latite in the northeastern embayment

into the Batamote Andesite.

Alteration

In view of the geochemical anomalies derived from it, the

Batamote Andesite is notable for its lack of significant alteration.

The only secondary minerals present in the unit are amygduloidal

zeolites, and joint and fracture filling chalcedony. However, a

"limonite" multispectral imaging anomaly occurs around the Batamote

plug (Gary Raines, U.S. Geological Survey, personal communication,

1984) .

On the other hand, an extensive zone of alteration was ob-

served in the Childs Latite in the northeastern embayment of this

unit into the Batamote Andesite. In this area, the unit has been

strongly argillized.

LITHOGEOCHEMISTRY

A total of 58 rock chip samples were collected within the

study area, pulverized and analyzed for 31 elements using semi -

quantitative emission spectro -scopy (Grimes and Marranzino, 1968). The

results of these analyses are given in Appendix Ia, while their

locations are given in Plate 2. Of these samples, 41 came from the

extrusive facies of the Batamote Andesite, three came from the intru-

sive facies of the Batamote Andesite, five came from the Childs

Latite, and six samples came from other rock types, including chalce-

dony, caliche and volcanoclastics. In addition, Gilluly (1946) and

Jones (1974) presented major element oxide analyses for Childs Latite

and Batamote Andesite within the region.

In this chapter, the analyses of the major and minor oxides

from other studies are reviewed, and the distribution of trace elements

in the Batamote Andesite and Childs Latite, especially copper, lead

and zinc, are discussed.

Major and Minor Elements

Gilluly (1946) reported analyses of rocks for 18 oxides and

sulfur, and Jones (1974) reported analyses for nine oxides. The

results of these two studies are summarized in Table 1. The analyses

indicate that the Childs Latite and the Batamote Andesite have

essentially the same concentrations of silica, alumina, ferric oxide,

soda and titanium oxide. On the other hand, the Batamote Andesite

33

34

has significantly higher concentrations of ferrous oxide, magnesia

and lime, while the Childs Latite has higher concentrations of

potash. The most marked difference is in magnesia, where the con-

centration in the Batamote Andesite is more than twice that of the

Childs Latite.

The mineralogy of these two rock types reflects the differ-

ence in their composition. The presence of olivine as the predomin-

ant mafic mineral in the Batamote Andesite reflects the high magnesia

content, while the presence of orthoclase and sanidine in the Childs

Latite reflects its higher potash content. Based on the relatively

high silica concent, Gilluly (1946) classified the Batamote Andesite

as an andesite, although he said true basalt flows may occur within

the Batamote Mountains.

Table 1-- Summary of major element oxide analyses of the Childs Latite

Oxide

and the Batamote Andesite (after Gilluly, 1946 and Jones, 1974)

Childs Latitel Batamote Andesite2Mean Range Mean Range

Si02 55.52 53.00-57.65 55.93 49.06-59.88

A1203 16.08 14.56-18.14 16.33 15.69-17.33

Fe203 4.70 2.29-5.61 4.09 3.10-5.38

Fe0 2.58 1.65-4.07 3.78 1.41-6.37

Mg0 1.73 0.52-3.22 4.14 2.74-6.17

Ca0 5.37 4.42-6.38 7.03 5.31-8.95

Na20 3.98 3.40-4.39 3.41 3.11-3.62

K20 3.80 2.36-4.27 2.22 1.52-3.25

TiO2 1.20 0.79-1.55 1.05 0.79-1.40

All values in weight percent.

1Four samples from Gilluly (1946) and four samples from Jones (1974)

2Five samples from Gilluly (1946)

35

The results of the semi -quantitative analyses for elements

that had greater than 75% unqualified values are summarized in Table

2. For statistical analysis, qualified values were assigned values

one and one -half of a spectrographic step below the detection limit

for "N" (not detected), and "L" (detected at levels below the detec-

tion limit), respectively. Because of the small population for the

Childs Latite, the standard deviations are not given. The semi -

quantitative nature of the data in Table 2 should be remembered.

The major and minor elements, as determined by semi- quanti-

tative emission spectroscopy, show the same relative abundances by

rock type as the oxide analyses. The Batamote Andesite has higher

concentrations of iron, magnesium, calcium, titanium and manganese.

For the Batamote Andesite, all major and minor elements have relatively

low standard deviations relative to their means. Only calcium has

a relatively high standard deviation.

Trace Elements

Trace elements are defined as elements that have abundances

of less than 0.1 percent (Levinson, 1980). Fourteen elements in

Table 2 have this characteristic. Of these, two (B and Be) have

significantly higher concentrations in the Childs Latite, which

probably reflects the more felsic nature of this unit. On the other

hand, seven elements (Co, Cr, Cu, Ni, Sc, Sr and V) have higher

concentrations in the Batamote Andesite, which reflects its more mafic

nature. Four elements (La, Pb, Y and Zr) have approximately the

same concentration in these two rock types. Barium proved to be

36

Table 2 -- Summary of emission spectroscopic analysis on the Childs

Element

Latite and Batamote Andesite

Childs Latite Batamote AndesiteStandard

Range Mean Range Mean Deviation

Fe (%) 0.3-2 1.1 2 -7 4.5 1.2

Mg (%) 0.2-1 0.48 1 -2 1.3 0.4

Ca (%) 0.2-1.5 0.82 1.5 -10 1.9 1.3

Ti (%) 0.03-0.3 0.12 0.2 -0.7 0.44 0.11

Mn 700-1000 760 1000 -2000 1200 330

B 20-70 42 10-50 19 7

Ba 50-500 190 300-1000 630 180

Be 1-7 4.7 L(1)-2 1.4 0.3

Co N(5)-10 3.8 10-30 20 7

Cr N(10) 5 10-150 34 29

Cu L(5)-10 6 15 -50 28 10

La 50-100 72 50 -100 82 21

Ni N(5)-20 5.6 10 -70 28 18

Pb 10-30 20 10 -30 19 5

Sr N(100)-500 190 500 500 0

V N(10)-50 23 50 -100 86 17

Y 20-30 22 10 -50 34 12

Zr 50-200 110 50 -300 199 58

Replacement values for qualified values

Element Qualified Value Element Qualified Value

N L N L

Be 0.5 0.7 Ni 2 3

Co 2 3 Sc 2 3

Cr 5 7 Sr 50 70

Cu 2 3 V 5 7

Values in parts per million unless otherwise indicated.

37

unusual in that it has higher concentrations in the andesite; yet,

in general, it is concentrated in more potassium -rich rocks (Levin-

son, 1980). Therefore with the exception of barium, major, minor and

trace elements conform to the expected relative abundances of the two

rock types.

As this study is concerned with the concentration of copper,

the distribution of base metals in the Batamote Andesite is important

to later interpretations. Figures 10 through 12 are histograms

showing the distributions of values of copper, lead and zinc, respec-

tively, in the extrusive facies of the Batamote Andesite.

Copper values have a restricted range of values characterized

by one mode at 30 ppm, indicating that the Batamote Andesite has a

relatively even distribution of copper. Moreover, because the average

abundance of copper in andesite is 55 ppm (Wedepohl, 1969) the Batamote

Andesite is somewhat depleted in copper relative to other rocks of

similar composition.

Lead has a similar restricted range of values around 20 ppm,

which is enriched relative to the 5.8 ppm average abundance in andes-

ite (Wedepohl, 1969). Zinc has an irregular distribution with values

up to 1000 ppm, but clustering around L(200). This distribution

indicates that zinc has a higher than average abundance relative to

andesite at 70 ppm (Wedepohl, 1969).

R -Mode Factor Analysis

R -mode factor analysis was performed on 41 samples from the

extrusive facies of the Batamote Andesíte, as this is the most

38

important rock in the study area. All elements, except strontium,

that had greater than 75% unqualified values using semi- quantitative

emission spectroscopy (18 total) were used in this analysis. Quali-

fied values were assigned numerical values as in earlier statistical

treatments of the data. Strontium was not used because it had no

variance over the sample population. The exact method used was

principal factoring with iterations and varimax rotation (c.f. Nie

and others, 1974). The results of the factor analysis are given in

Table 3, and a graphical depiction of the factor loadings (which

represent both correlation coefficients and regression weights be-

tween the elements and the factors) is given in Figure 13.

Four initial factors with eigenvalues greater than one (i.e.

the factor explains a greater amount of the total variance than is

explained by a single element), explained 70.5% of the total variance

within the data. The other 14 initial factors explained 29.5% of

the variance.

When terminal factors were determined by iteration, the first

two factors accounted for 81.0% of the total variance. The other two

terminal factors explained less than 20% of the variance; they have

much less importance than the first two factors. Low communalities

(less than 0.5) for titanium and boron imply that the four terminal

factors do not explain the variance of these elements well; other

factors played a greater role in determining their concentrations.

Factor 1 probably represents the mafic component of the

Batamote Andesite; it corresponds very well with the ferride assem-

blage of Theobald and Barton (1983). High positive factor loadings

VALUE

(PPM)

N(5)

L(5)

5

7

10

15

20

30

50

FREQUENCY

5 10 15 20

39

figure 10 -- Histogram showing the distribution of copper in the Batamote

Andesite

VALUE

(PPM)

N(10)

L(1O)

10

15

20

30

O

FREQUENCY

5 10 15 20 25 30

Figure 11 -- Histogram showing the distribution of lead in the BatamoteAndesíte

40

VALUE FREQUENCY

(PPM) 0 5 10 15 20 25 30

N(200)L(200)2003005007001000

Figure 12 -- Histogram showing the distribution of zinc in the BatamoteAndesite

41

Table 3-- Results of R -mode principal factor analysis with iterations

after varimax rotation for the extrusive facies of the Bata -

mote Andesite, Batamote Mountains, Arizona

Element Communality Factor Loadings

Factor 1 Factor 2 Factor 3 Factor 4

Fe 0.66560 0.78658 0.18030 0.02773 0.11667

Mg 0.61128 0.67672 -0.32253 0.21855 -0.03932

Ca 0.75973 0.04594 -0.07245 -0.03935 0.86650

Ti 0.38460 0.33886 0.51152 0.00967 0.08959

Mn 0.55794 0.17178 0.18675 0.70138 0.04017

B 0.19663 0.24489 0.28708 -0.22155 0.07184

Ba 0.39957 -0.10538 0.52316 0.30878 0.13938

Be 0.61659 -0.19760 0.70325 0.24807 -0.14645

Co 0.72540 0.78461 -0.10914 0.30995 0.04253

Cr 0.70063 0.62398 -0.55629 0.04274 -0.00172

Cu 0.51839 0.42356 0.13340 0.56102 -0.08020

La 0.82499 0.04252 0.86665 -0.13663 -0.23114

Ni 0.92211 0.82012 -0.47226 0.15327 -0.05122

Pb 0.66127 -0.02951 0.71231 0.39013 -0.03104

Sc 0.73552 0.76293 0.17019 0.12324 0.33062

V 0.68194 0.80772 0.11867 -0.10038 -0.07330

Y 0.69455 0.36794 0.59870 0.22903 0.38508

Zr 0.64201 -0.13381 0.78843 0.02032 0.04560

Factor Eigenvalue Percent of Variance Cummulative Percent

1 4.93591 43.7 43.7

2 4.22015 37.4 81.0

3 1.12328 9.9 91.0

4 1.01915 9.0 100.0

FA

CT

OR

11.

0T

0.0

Ni -V

Fe

Co

Sc

Cr

Mg

-Cu

YT

iB

gM

n Fe

Mn

Sc

Cu

FA

CT

OR

2

Cu

LaP

bB

aZ

r

-1.0

Bç

FA

CT

OR

3 Mn

Cu

Pb -C

oB

aBe

NiM

9C

rSc

ZrF

e Ti

Ca

vLa -- B

FA

CT

OR

4 Sc

Fe

Ba Ti

BZ

rC

oMn

MP

b

gNi

VC

u

geLa

Figure 13 -- Factor loadings for 18 elements from R -mode factor analysis of the Batamote Andesite

43

clearly group elements with a mafic association (Ni, V, Fe, Co,

Sc, Mg and Cr). Additionally, elements with a felsic association

(e.g. Be, Zr, Pb and La) tend to have either a low or negative

factor loading.

Conversely, factor 2 probably has a felsic or intermediate

association. In this case three groupings of elements can be seen:

a group with high positive loadings (La, Zr, Pb, Be, Y, Ba and Ti), a

group with low absolute factor loadings (B, Mn, Fe, Sc, Cu, V,

Ca and Co), and a group with high negative loadings (Mg, Ni and

Cr). With the exception of titanium, the elements in the first

group --the group that defines the factor --all have a felsic or

intermediate association; the elements in the third group --which

has a negative correlation with the factor --have a more mafic

association. This factor, therefore, seems to be positively correl-

ated with the intermediate to felsic component of the rock.

The nature of the other two factors is much less straight-

forward. Factor 3 separates manganese and copper, with relatively

high factor loadings, from the rest of the elements. Possibly this

factor could be associated with the copper anomalies discussed later

in this report. Factor 4 separates calcium and possibly yttrium

and scandium from the other elements. It could represent calcite -

filled amygdules or the effect of caliche on the samples. Both

these factors account for relatively little variance (less than

10% each).

STREAM SEDIMENT GEOCHEMISTRY

A total of 101 stream sediment samples were collected from

89 sites. The samples were collected in three phases: 1. A pre-

liminary phase to check the anomalies observed by Barton and others

(1982); 2. The main phase to define the distribution of copper; and

3. Follow -up work to determine the changes in the concentration of

copper upstream along anomalous drainages. Sample locations, along

with the drainage patterns and areas of influence of the samples,

respectively, are given in Plates 3 and 4. The samples were analyzed

using semi- quantitative emission spectroscopy (Grimes and Marranzino,

1969; E.F. Cooley, U.S. Geological Survey, personal communication,

1983), a hot nitric acid leach (modified after Ward and others, 1969)

and two sequential extraction techniques. The results of the semi -

quantitative emission spectroscopic analysis are presented in Appendix

Ib; the analytical methods are described in Appendix II; and the

results of the chemical analyses are given in Appendices IIIa through

IIIb.

Preliminary Phase

To confirm the results of the survey by Barton and others

(1982) and to check the possibility of contamination from the Ajo

smelter, seven stream sediment samples were collected in December

1982. Of these, two (AJ001S and AJ002S) came from washes that

drained the Valley of the Ajo, which lies between the smelter and

44

45

the area of interest, while the others drained the Batamote Mountains.

Using nylon and aluminum screens, five size fractions were

sieved and then pulverized to -200 mesh. The size fractions are:

-30 mesh ( <600 pm), 30 mesh to 80 mesh (600 pm to 180 pm), 80 mesh

to 150 mesh (180 pm to 100 pm), 150 mesh to 200 mesh (100 pm to

75 pm), and -200 mesh ( <75 pm). Each size fraction was analyzed

for copper with atomic absorption spectrophotometry using a hot

nitric acid leach (see Appendix II). The results of this analysis

are given in Table 4.

The results of this preliminary phase indicate that the

anomalies described by Barton and others (1982) are real, that air-

borne smelter contamination is not significant, and that -30 mesh

stream sediment is perfectly adequate for more detailed work.

The values of 100 to 190 ppm copper in the -30 mesh fraction

correspond nicely with the anomalous values ranging from 100 to 200

ppm copper reported by Barton and others (1982). Consequently,

further work was justified.

Smelter contamination was considered unlikely at the end of

this phase of the study for two reasons. First, high values persist

on the eastern (downwind) side of the Batamote range. Samples

AJ003S, AJ005S and AJ007S came from this area; their values remain

anomalous, especially in light of the background values of copper

in the Batamote Andesite. Additionally the intensity of the anomaly

does not increase significantly on the west side of the range as

might be expected with airborne contamination.

46

Table 4-- Concentrations of copper in selected stream sediment samples

Sample

relative to particle size

Size Classes (U.S. Standard Mesh)-30 -301+80 -80/ +150 -150/ +200 -200

AJ001S 170 190 190 160 230

AJ002S 90 60 30 140 170

AJ003S 140 120 120 160 290

AJ005S 120 120 120 120 160

AJ007S 110 120 130 140 190

AJ008S 190 170 200 210 260

AJOlOS 130 110 130 170 220

Second, high copper values are present in the coarsest

fractions of the samples. For a typical smelter, 50% of the smelter

dust passes through a 400 mesh screen, and 80% of the dust passes

through a 150 mesh screen. (E. Partelpoeg, Phelps Dodge, personal

communication, 1984). Therefore, barring sorption, airborne contam-

ination would be important only in the finest fractions. Although

the concentrations of copper increase with decreasing grain size

(which is expected anyway), the presence of anomalous values in the

-30/ +80 mesh fraction argues against airborne smelter contamination.

Additionally, the results of later work also argue against this

mechanism.

Finally, the -30 mesh size fraction proved to give adequate

values and reasonable contrast. Therefore to minimize effort in

sample preparation and to decrease problems with eolian transport

and contamination, the -30 mesh size fraction was chosen for further

work.

47

Main Phase

The second phase of stream sediment collection involved

sampling 78 sites at a sampling density of 0.89 samples /tang to

determine the distribution of copper in the Batamote Mountains.

Each of the preliminary sample sites in the mountains was resampled;

replicate samples were collected at seven additional sites. Repli-

cate stream sediment sample pairs are listed in Table 5:

Table 5-- Replicate stream sediment sample pairs

AJ003S- AJ036S AJ010S- AJO3OS AJ096S- AJ097S

AJ005S- AJO11S AJ083S- AJ084S AJ098S- AJ099S

AJOO7S- AJ021S AJ087S- AJO88S AJ1O3S- AJ104S

AJOO8S- AJO29S AJ091S- AJ092S AJ105S- AJ106S

Field Methods

At each sample site, stream sediment and heavy mineral con-

centrate samples were collected. Sediment, composited along a 100

foot reach of channel, was screened through a 5 mm sieve in the field.

Between 400 and 1600 g (usually 500 to 1000 g) of -5 mm sediment was

collected as a stream sediment; between 1500 and 3500 g (usually

2000 to 3000 g) were collected as a heavy mineral concentrate.

Sample Preparation

In the laboratory the stream sediment samples were sieved

to -30 mesh and split. Between 30 and 80 g were pulverized to -200

mesh. The rest was saved for later investigations. The +30 mesh

material was discarded.

48

Results of the Hot Nitric Acid Extraction

All samples were analyzed for copper using atomic absorp-

tion spectrophotometry with a hot nitric acid extraction (see

Appendix II for technique). The extraction solubilizes all adsorbed

ions and most common sulfides and oxides. However, it is not total

because silicates are not attacked to a significant degree (Ward

and others, 1969).

The results (see Appendix IIIa) of this analysis suggested a

bimodal frequency distribution, with one mode at 75 ppm and the other

mode at 150 ppm (see Figure 14). Two anomalous areas (defined using

a threshold of 100 ppm) separated by a trough of lower values occur

in the northwest and north -central parts of the study area (see

Plate 5). The values trail off to the east and southeast to values

around 50 ppm.

The northwestern anomaly (which has values up to 280 ppm) has

a strong spatial association with the northerly trending normal

faults described earlier in this paper. However, the easternmost

fault in this group lies within the trough of low copper values.

The north -central anomaly (which has values up to 150 ppm)

has no obvious structural or lithological control. Conceivably,

it could be a continuation of the northweatern anomaly. In fact,

later analyses tend to support this hypothesis.

Results of Semi -Quantitative Emission Spectroscopic Analysis

Each sample was analyzed for 31 elements using semi- quanti-

tative emission spectroscopy (Grimes and Marranzino, 1969) modified

49

RANGE(PPM)

1- 2526- 5051- 7576-100

101 -125

126 -150

151 -175176 -200201 -225226 -250251 -275276 -300

FREQUENCY0 5 10 15 20

3

3

Figure 14 -- Histogram showing the distribution of copper (extractedusing hot nitric acid) in -30 mesh stream sediments

50

to lower the detection limits of certain elements (Ag, As, Au,

Be, Bi, Cd, Cu, Pb, Sb, Sn, W and Zn; E.F. Cooley, personal communi-

cation, 1983). The results (see Appendix Ib) indicated anomalous

areas in the northwest and north -central part of the study area

characterized by highs of copper, silver and bismuth.

Copper. The results of semi -quantitative emission spectro-

scopic analysis of copper, an analysis for total copper, are similar

to the results for the hot nitric acid extraction. Both procedures

show a bimodal frequency distribution and similar areal distributions.

In fact, the two procedures have a correlation coefficient of 0.8185

based on 92 samples. Therefore, owing to the high variance inherent

in semi -quantitative emission spectroscopy, only the results for the

nitric acid extraction are presented graphically in this paper.

Silver and Bismuth. Both silver and bismuth mimic the anomaly

pattern observed in copper. Figures 15 and 16 and Plates 6 and 7

show the frequency and areal distributions of silver and bismuth,

respectively. High silver values (greater than or equal to L(0.1))

have a wider distribution than the high copper values, yet they occur

in the same general areas. Bismuth shows a distribution that has

a better visual correlation with copper than silver. A trough of

low values, corresponding with the one for copper, also appears in

the bismuth map; the trough is not apparent on the silver map. As

the values reported are right at the detection limit (especially for

bismuth), the true backgrounds for these two elements could not be

determined.

VALUE

(PPM)

N(0.1)

L(O.1)

0.1

0.15

0.20,3

0.50.7

1

FREQUENCY

0 5 10 15 20 25 30 35

51

Figure 15 -- Histogram showing the distribution of silver (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh stream

sediment

VALUE

(PPM)

N(2)

L(2)

2

FREQUENCY

0 5 10 25 30 40 45

Figure 15 -- Histogram showing the distribution of bismuth (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh streamsediment

52

Silver is a chalcophile element that is typically associated

with copper in "red bed" sandstone deposits and some porphyry copper

deposits. Crustal abundance averages 0.07 ppm and ranges from 0.04

ppm in felsic rocks to 0.1 ppm in mafic rocks (Levinson, 1980).

For intermediate igneous rocks, average abundance is 0.07 ppm (Wede-

pohl, 1969). It has a high mobility in the primary environment,

but is only slightly mobile in oxidizing, acid and gley secondary

environments (Levinson, 1980). Consequently, the association of sil-

ver with copper is not unusual; however, the lower values of silver

are near the background for andesites.

A chalcophile element, bismuth has a crustal abundance of

0.17 ppm, which implies that the observed anomaly of 2 ppm is signif-

icant. The abundance of bismuth varies from 0.1 ppm in felsic rocks

to 0.15 ppm in mafic rocks. Bismuth can occur with copper in poly -

metallic deposits. Although its mobility in the primary environment

is high, it has a very low mobility at the surface, commonly precip-

itating with iron oxides (Levinsion, 1980). However, relatively

little is known about the detailed geochemical behavior of this

element.

Within the Ajo 1° by 2° quadrangle, bismuth has an association

with the Precambrian. It best characterizes a "half- moon" shaped

Bi -Pb -Mo anomaly, centered over a magnetic bullseye (possibly indi-

cating a shallow intrusive) in the presumed Precambrian of the

Mohawk Range, northeast of the study area (P.K. Theobald, U.S. Geo-

logical Survey, personal communication, 1984). Elsewhere in

southern Arizona bismuth has been observed in pegmatites and is

53

associated with pyrometasomatic deposits in the Pima District

(Cooper, 1962).

Other Base Metals. Plate 8 shows the distribution of anomal-

ous values of molybdenum, lead, tin and zinc in -30 mesh stream sed-

iment. Figures 17 through 20 show the frequency distributions for

the same elements. Of these, only anomalous values of tin (ranging

from L(5) to 10 ppm) seem to be associated with the copper- silver-

bismuth anomaly. The anomalous values of molybdenum, lead and zinc

occur in no recognizable systematic way throughout the study area.

This, in combination with the relatively low values of the anomalies,

suggests that they are not significant.

R -Mode Factor Analysis. R -mode factor analysis was performed

on the stream sediment data using the same criteria and methodology

described earlier in the chapter on lithogeochemistry (replacements

of qualified data were different as different lower detection limits

were used). In this case, strontium was used in the analysis be-

cause it had siggíficant variance. The results of the analysis are

given in Table 6 and graphically depicted in Figure 21.

Five initial factors with eigenvalues greater than one

accounted for 67.5% of the total variance. Fourteen other initial

factors accounted for 32.5% of the total variation.

After transformation to terminal factors, the first factor

explained 59.8% of the variance - -by far the dominant factor. The

other factors each explained 15.6% or less of the variance. So in

this case there is one dominant factor and four lesser factors.

VALUE

(PPM)

N(5)

L( 5)

5

7

10

FREQUENCY

0 5 10 70 75

3

54

Figure 17 -- Histogram showing the distribution of molybdenum (analyzedusing semi- quantitative emission spectroscopy) in -30 mesh

stream sediment

VALUE

(PPM)

N(2)

L(2)

2

3

5

7

10

15

20

30

50

70

100

150

200

300

FREQUENCY

0 5 10 15 20 45 50

J7

Figure 18 -- Histogram showing the distribution of lead (analyzed using

semi -quantitative emission spectroscopy) in -30 mesh stream

sediment

VALUE

(PPM)

N(5)

L(5)57

10

FREQUENCY

0 5 10 70 75

55

Figure 19 -- Histogram showing the distribution of tin (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh streamsediment

VALUE

(PPM)

N(50)

L(5O)

5070

FREQUENCY

0 5 10 6 0

Jl

Figure 20-- Histogram showing the distribution of zinc (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh streamsediment

56

Table 6 -- Results of R -mode principal factor analysis with iterationsafter varimax rotation for -30 mesh stream sediments, Batamote

Element

Mountains, Arizona

CommunalityFactor 1

Factor LoadingsFactor 2 Factor 3 Factor 4 Factor 5

Fe 0.74229 0.69705 0.33028 0.31758 0.18934 0.10304Mg 0.74964 0.84115 0.12003 0.05638 -0.07092 0.13959Ca 0.26428 0.18574 -0.07881 0.39103 0.14340 0.22382Ti 0.91213 0.35775 0.83552 0.25571 0.09664 0.01646Mn 0.46846 0.60964 0.15351 0.01800 0.21378 0.16494

B 0.41485 -0.51733 -0.05579 -0.21456 -0.20552 -0.23630Ba 0.68883 0.39648 0.48920 0.08998 0.53036 -0.05418Be 0.28242 -0.37576 0.00893 0.15277 -0.29445 0.17634Co 0.76290 0.80419 0.32809 0.07367 -0.03520 0.04324Cr 0.73356 0.72339 0.12224 -0.29935 -0.23905 0.22038

Cu 0.54530 -0.22608 -0.05215 -0.26265 -0.07471 -0.64568La 0.32292 -0.16380 0.14914 0.37634 0.33595 0.13910Ni 0.54275 0.63838 0.22980 -0.20687 -0.04416 0.20535Pb 0.31048 -0.07723 0.04165 -0.04738 0.54749 0.02800Sc 0.90160 0.85625 0.07096 0.36210 -0.14707 -0.10332

Sr 0.59892 0.44652 0.30450 0.33982 0.38647 0.20490V 0.46831 0.45452 0.46389 -0.17469 0.12519 0.01850Y 0.47772 -0.01590 0.11381 0.65063 -0.20183 0.02171Zr 0.36704 -0.05413 -0.03312 0.00217 0.01597 -0.60229

Factor Eigenvalue Percent of Variance Cummulative Percent

1 6.31778 59.8 59.82 1.64818 15.6 75.43 1.15515 10.9 86.44 0.84477 8.0 94.45 0.59299 5.6 100.0

FA

CT

OR

11.

0

Mg

Sc

Co

Cr

Ni

Fe

-Mn

FA

CT

OR

2

Ti

VB

a

Ba

Fe

Co

-Ti

Sc

.

Mnn

Ca

LaM

_ gCr

0.0

Zr

YP

bS

c

-1.0

Pb

Cu

LaC

a-C

uB

e

B

FA

CT

OR

3

a

Y

Sc

La-S

rF

eTi

Be oB

a

Mñ

gP

bS

r

Ni

V

-B

Cu

Cr

FA

CT

OR

4

Pb

Ba

Ca

Sr

Cr

Ni

LaS

rB

eM

nM

gLa

Mg

Fe

Co

Y Ba

FA

CT

OR

5

Mn

Ca

ZrT

i Co

CuM

gS

c B Be

Figure 21-- Factor loadings for 19 elements from R -mode factor analysis of stream sediments

58

As with the bulk rock analysis, the dominant factor is rela-

tively easy to explain, but the four lesser factors are problematic.

Factor 1 in stream sediments has relatively high loadings for

scandium, magnesium, cobalt, chromium, iron, nickel and manganese,

with possible associations of vanadium, strontium and barium. As

with factor 1 in the bulk rock analysis, most of the elements with

high loadings are associated with mafic rocks. Additionally, boron

and beryllium, elements associated with felsic rocks, have high

negative loadings, indicating a negative correlation with the factor.

Therefore, factor 1 probably reflects the mafic component of the

Batamote Andesite, which crops out in the majority of the sampled

area. It also corresponds to the ferride factor of Theobald and

Barton (1983).

Factor 2 is characterized by high factor loadings for titanium,

barium and vanadium; factor 3 has high loadings for yttrium, and

possibly calcium, lanthanum, scandium, strontium, iron and titanium;

factor 4 has high loadings for lead, barium, strontium and lanthanum;

and factor 5 has high negative loadings for copper and zirconium.

Of these, only factor 5 has meaning in context of this study.

In it, copper and zirconium are the controlling elements, with some

possible contribution from boron. These three elements are distinctly

separated from the other elements. Both boron and zirconium are

weakly correlated with copper (correlation coefficients are 0.4466

and 0.4153, respectively). Also high values of boron and zirconium

do occur in the anomalous areas as defined by copper. Therefore,

59

this factor might reflect the mechanism that produced the anomalous

values observed.

The factors with obscure explanations could represent contri-

butions to the sediment from a single mineral or suite of minerals.

Factor 2 could represent rutile and other titanium oxides and hydrox-

ides; factor 3 could represent the presence of xenotime or monazite

(thorium was found in the non - magnetic fraction of heavy mineral

concentrates); and factor 4 could relate to the presence of potassic

feldspar as lead, barium and strontium are common trace elements

in this mineral.

In the final factor solution, the five factors explained

less than 50% of the variance for calcium, manganese, boron, beryllium,

lanthanum, lead, vanadium, yttrium and zirconium. Additionally,

several other elements have low communalities. Therefore many other

factors are required to explain the variance beyond the five terminal

factors generated.

Results of the First Sequential Extraction

To determine the mineralogic distribution of copper within

the stream sediment samples, two sequential extractions were performed.

The first, which was performed on one sample from each site, involved

three steps. First, hot oxalic acid was used to remove the "oxide"

fraction (T.T. Chao, U.S. Geological Survey, personal communication,

1983). Then a combination of potassium perchlorate and cold hydro-

chloric acid was used to remove the "reduced" (i.e. sulfide and

organic) fraction (Glade and Fletcher, 1974). Finally an aqua

60

RANGE FREQUENCY

or 102) 0 5 10 15 20 25

0.01-0.250.26-0.500.51-0.750.76- 1.001.01- 1.25

1.26-1.501.51- 1.75

1

1.76-2.002.01-2.252.26-2.502.51-2.752.76-3.003.01-3.253.26-a5O3.51-3.753.76-4.004.01-425

Figure 22-- Histogram showing the distribution of copper normalized toiron (extracted using hot oxalic acid) in -30 mesh stream

sediment

RANGE(PPM)

1- 1011- 2021- 3031- 4041- 5051- 6061- 7071-8081 -9091 -100

101 -110

O

FREQUENCY

5 10 15 20 25

Figure 23 -- Histogram showing the distribution of copper (extractedsequentially using potassium perchlorate and hydrochloric acid

after oxalic acid) in -30 mesh stream sediment

61

regia /hydrofluoric acid leach was used to determine the residual

fraction for 20 samples (Filipek and Owen, 1978). The analytical

methods are presented in Appendix II, while the results are pre-

sented in Appendix llla. The results of each step are summarized

in the following discussion.

Oxalic Acid Leach. To minimize the effects of large vari-

ations in the concentrations of iron, copper values were normalized

to iron. Figure 22 and Plate 9 give the frequency and areal distri-

butions for this extraction. In this extraction, a unimodal

frequency distribution was produced with an upper shoulder. Assuming

the shoulder to contain the anomalous values, the threshold was set at

0.0100.

With this threshold, anomalous values occur in the areas

defined by the nitric acid extraction. Although the area covered

by the northwestern anomaly does not change, the north -central

anomaly is significantly reduced in area as anomalous values do not

extend as far to the north.

This leach accounted for between 30 and 61% of the total

copper in the stream sediments (calculated using the sum of the

different fractions as the total; for samples in which the residual

fraction was not determined, a value of 15 ppm was assumed). Within

the anomalous population, the percentage of copper extracted using

oxalic acid ranged from 40 to 61% of the total (x = 48.44 %, s = 4.51 %,

n = 21); on the other hand, in the non -anomalous population, the

percentage of total copper ranged from 30 to 57% (x = 43.20 %,

s = 6.40 %, n = 53). At the 95% confidence level, these two

62

populations are statistically different, indicating that in the

anomalous samples, the oxide fraction constitutes a greater propor-

tion of total copper than in the non -anomalous samples. This is

probably due to the increasing relative importance of copper in the

residual fraction of the non -anomalous population. While the copper

concentration in the oxide fraction decreases in the non -anomalous

samples, the residual concentration remains constant and has a

higher relative contribution.

In general, the oxalic acid extractable fraction contains

more copper than the potassium perchlorate -hydrochloric acid extract-

able fraction. Only in sample AJ001S, which came from a wash

draining the area containing the New Cornelia tailings ponds, does

the reduced fraction predominate over the oxide fraction. In all

but the lowest background samples, the oxide fraction predominates

over the residual fraction. In summary, the oxide fraction is

quantitatively the most important fraction of this sequential

extraction.

Potassium Perchlorate -Hydrochloric Acid Leach. This extract -

tion, originally designed for the analysis of base metal sulfides

(Olade and Fletcher, 1974), attacks the sulfide and organic portion of

the sample. Both the frequency and areal distributions for the copper in

this step are slightly different from those of the oxalic acid and

nitric acid extractions. Figure 23 and Plate 10 show the frequency

and areal distributions for this extraction.

The frequency distribution for this step has the appearance

of a log - normal distribution, as opposed to the bimodal distribution

63

observed in the nitric acid extraction. Due to the form of the dis-

tribution, the threshold is not obvious. However, the values in

the northwestern anomalous area increase upwards from 40 ppm,

suggesting that this is the probable threshold.

With this threshold, the north -central anomaly does show up,

but with significantly less contrast than in the other methods.

Moreover, this anomalous area is more spread out, with no distinct

highs. The northwestern anomaly does not change significantly in

either areal extent or character. As with the other techniques,

the values decrease to southeast to values around 10 to 20 ppm.

Therefore this extraction shows the same areal distribution

as the other methods; however, the frequency distribution is signif-

icantly different, suggesting additional or different processes

controlled the dispersion of copper into the sulfide and organic

fraction of stream sediments.

Aqua Regia /Hydrofluoric Acid Leach. This extraction is

designed to decompose silicate minerals, releasing copper and other

trace elements from silicate structures (Filipek and Owen, 1974).

Owing to the time required and the difficulty of the procedure,

only 20 samples were analyzed. Samples were chosen to include both

anomalous and background samples as indicated by previous analyses.

The results indicate that this fraction has a relatively uniform,

low distribution throughout the study area. Values ranged from 8 to

19 ppm with an average of 14.05 ppm (s = 3.03 ppm). By inspection,

high values from this extraction show no correlation with high

64

values from other extractions. Therefore, copper extracted using

this method probably represents the lithogeochemical background.

Summary. The first sequential extraction indicated that the

copper that constitutes the anomalous values probably resides in

both the oxide, and organic and sulfide portions of the stream sediment.

The technique does not give any indication of exactly how the copper

is held in these two chemical fractions. Copper held in the silicate

framework of the stream sediment does not contribute to the anomalous

values.

Results of the Second Sequential Extraction

To determine the mineralogic fractions that holds the copper,

a second, more selective sequential extraction (modified after Filipek

and Owen, 1978; modified after Chao and Zhou, 1983) involving five

separate steps was used. The concentrations of manganese and iron

were also determined in each step. The steps were intended to

remove the carbonate and exchangeable fraction, followed by the

easily reducible, moderately reducible, sulfide and organic, and

crystalline (silicate) fractions. Although the steps attack princi-

pally the mineralogic fractions described, they are not perfectly

selective, so the values determined cannot be taken as a strict

description of the behavior of these elements according to the

mineralogic fraction.

To further define the phases that hold the copper, samples

were separated into three parts using bromoform: the portion that

sinks (the "heavies "), the portion that remains suspended (the

65

"slimes "), and the portion that floats (the "lights "). The informal

terms "heavies ", "slimes ", and "lights" will be used in this paper

for clarity and efficiency. The heavies contain minerals that have

a specific gravity of greater than 2.90 (the specific gravity of

bromoform) -- typically amphiboles, pyroxenes, olivine, sulfides and

other heavy minerals. The slimes contain minerals that have spe-

cific gravities of about 2.90 and flocculant minerals such as clays.

The lights contain minerals that have specific gravities less than

2.90 such as feldspars, calcite and quartz. All three fractions

were pulverized to -200 mesh and analyzed using the five -step extract-

ion. Additionally a bulk sample was also analyzed, making a total

of four separates per stream sediment sample.

Owing to the length of the procedure, only ten stream sedi-

ment samples were analyzed in this manner. Four were selected from

the anomalous group of samples, three from a group considered

borderline anamalous, and three from samples representing the

background. For comparison, a sample running 300 ppm copper held as

chrysocolla was prepared and analyzed. Table 7 lists the samples

selected. All four samples from the anomalous group came from the

northwest anomaly, while samples AJ012S and AJ015S of the borderline

Table 7 -- Samples analyzed using five -step sequential analysis

Anomalous Group: AJ019S, AJ038S, AJ039S and AJ040S.

Borderline Group: AJ012S, AJ015S and AJ049S.

Background Group: AJ069S, AJ094S and AJ103S.

66

anomalous group came from the north -central anomaly. The results of

this sequential extraction are given in Appendix IIIb, and they are

graphically displayed in Figure 24.

In general, the heavies have the highest concentrations of all

elements of interest in all mineralogic fractions, while the lights

have the lowest concentrations. Because the lights comprise the

bulk of the samples (always greater than 87% by weight), the bulk

analyses reflect those of the lights.

The Distribution of Iron and Manganese. More specifically,

both iron and manganese concentrate in the silicate fraction of the

heavies, slimes and lights. In fact, the heavies contain up to 29%

iron in this fraction. The other mineralogic fractions contain

less iron and manganese by several orders of magnitude. Of the

other fractions, the moderately reducible, and the sulfide and organic

fractions contain most of the rest of the iron, whereas the manganese

content does not vary significantly. In both the moderately reducible,

and the sulfide and organic fractions, the heavies and slimes contain

the most iron. The concentrations of manganese and iron vary inde-

pendently of the concentration of copper, although the sulfide and

organic fraction of the anomalous samples does contain more iron

than that of the borderline and background samples.

The greatest variation between samples, density separates

and mineralogic fractions occurs in the concentration of copper.

The anomalous samples contain significantly more copper in all

mineralogic fractions for heavies, slimes and lights. The heavies

and slimes contain more copper than the lights.

PPM1000 --

700

0CHYSOCOLLA

500

300

BH S L

AJ019S

B H S L O H S L

AJ03BS AJ039SANOMALOUS SAMPLES

200

100

O

200

100

0

ñB H S L

AJ012SB H S L B H S L

AJO15S AJ049S

BORDERLINE SAMPLES

ii:i%

v, j.=°' ..:_ T.! 7:77.

BH S L

AJ069SB H S L B H S l

AJ094S AJ103S

BACKGROUND SAMPLES

SYMBOL

®Iilil

8 H S L

AJ04OS

FRACTION

CRYSTALLINE

SULFIDE AND ORGANIC

MODERATELY REDUCIBLE

EASILY REDUCIBLE

CARBONATE ANDEXCHANGEABLE

B BULK

H HEAVIES

S SLIMES

L LIGHTS

67

Figure 24 -- Distribution of copper among mineralogic and densityfractions of selected stream sediments, Batamote Mountains,

Arizona

68

The Distribution of Copper in the Crystalline Fraction. Of

the five fractions analyzed, the least variation occurs in the crys-

talline fraction. Although the heavies and slimes do contain more

copper in this fraction, the difference is small compared to the

variations seen in other fractions. Additionally, the concentrations

of iron and manganese in this fraction do not vary significantly

relative to total copper content. This indicates that the crystalline

fraction represents a background value; copper in other fractions

determine whether a sample is anomalous or not.

The Distribution of Copper in the Carbonate and Exchangeable

Fraction. The carbonate and exchangeable fraction shows large

variation between anomalous and background, and between heavies,

slimes and lights. Anomalous samples have a 10 to 20 times enrich-

ment over the background in this fraction. Moreover, the heavies

show a two to four times enrichment over the lights and a lesser

enrichment over the slimes. However, the percentage of total copper

accounted for by this fraction increases significantly from background

to anomalous samples; the percentage does not increase as markedly

for the slimes and heavies. This implies that the lights are

affected the most by this mineralogic fraction.

The Distribution of Copper in the Easily Reducible Fraction.

On the other hand, although the anomalous samples have higher concen-

trations in the easily reducible fraction, the concentrations do not

vary significantly between heavies, slimes and lights. The nature of

the extraction and the low variation between the density separates

suggest that this fraction occurs ubiquitously through the sample,

69

probably as coatings on grains. The relatively low contribution of

this fraction to total copper and its ubiquitous nature indicate

that it is a quaternary affect of tertiary dispersion in the stream

sediment- -i.e., it is a product of higher order dispersion of the

copper introduced into stream sediment by secondary processes.

The Distribution of Copper in the Moderately Reducible, and

Sulfide and Organic Fractions. The moderately reducible, and sulfide

and organic fractions show the greatest variability between heavies,

slimes and lights, and between anomalous and background. Both

fractions have higher copper concentrations in the anomalous samples

and in the heavies and slimes. The sulfide and organic fraction,

by far, has the largest contribution of copper in the heavies and

slimes, implying that it controls the distribution of copper within

these two density separates. The distribution of the moderately

reducible fraction in the heavies and lights mimics this pattern.

However, in the lights the easily reducible and moderately reducible

fractions control the distribution of non -silicate copper. In com-

parison, the sulfide and organic fraction contributes relatively

little copper to the lights. This distribution is prevalent in the

anomalous and borderline samples; in background samples, the moder-

ately reducible, and sulfide and organic fractions contribute little

copper in comparison to the crystalline fraction.

Summary. To summarize, the crystalline fraction represents

a regional background concentration of copper. The anomalous values

stem from concentrations of copper in the carbonate and exchangeable,

easily reducible, moderately reducible, and sulfide and organic

69

probably as coatings on grains. The relatively low contribution of

this fraction to total copper and its ubiquitous nature indicate

that it is a quaternary affect of tertiary dispersion in the stream

sediment- -i.e., it is a product of higher order dispersion of the

copper introduced into stream sediment by secondary processes.

The Distribution of Copper in the Moderately Reducible, and

Sulfide and Organic Fractions. The moderately reducible, and sulfide

and organic fractions show the greatest variability between heavies,

slimes and lights, and between anomalous and background. Both

fractions have higher copper concentrations in the anomalous samples

and in the heavies and slimes. The sulfide and organic fraction,

by far, has the largest contribution of copper in the heavies and

slimes, implying that it controls the distribution of copper within

these two density separates. The distribution of the moderately

reducible fraction in the heavies and lights mimics this pattern.

However, in the lights the easily reducible and moderately reducible

fractions control the distribution of non -silicate copper. In com-

parison, the sulfide and organic fraction contributes relatively

little copper to the lights. This distribution is prevalent in the

anomalous and borderline samples; in background samples, the moder-

ately reducible, and sulfide and organic fractions contribute little

copper in comparison to the crystalline fraction.

Summary. To summarize, the crystalline fraction represents

a regional background concentration of copper. The anomalous values

stem from concentrations of copper in the carbonate and exchangeable,

easily reducible, moderately reducible, and sulfide and organic

71

Follow -Up Phase

To check the distribution of copper in anomalous drainages,

samples were collected upstream of samples AJ003S and AJ039S.

Stream sediment samples with numbers greater than 140 are part of

this group. The samples were analyzed using semi- quantitative

emission spectroscopy (with higher detection limits, however), the

nitric acid leach, the oxalic acid leach, and the potassium perchlor-

ate- hydrochloric acid leach. These results are given in Appendices

Ia and IIIa. All analyses illustrate the same observation:

anomalous concentrations of copper do not change significantly up

drainage. Figures 25 and 26 depict this point using the results of

the oxalic acid leach.

The lack of significant variation upstream from anomalous

samples implies that the input of anomalous copper occurs through-

out the drainage area of anomalous sample sites. This argues against

input from a single structure, or localized mineralization. Instead,

the copper came from a source that does not change in intensity over

a wide area.

Summary of the Information Derived From Stream Sediments

Analysis of stream sediments yielded two anomalous areas

characterized by high concentrations of copper, bismuth and silver.

The presence of anomalous values on both sides of the Batamote

Mountains and the presence of significant copper in coarse sediment

indicate that airborne smelter contamination is unlikely.

Tba

142(1.28)

143(1.47)'Tba..3$(2.27) ` f

.

P>././

\ K137(1.40 --/ Qa

2000 FEETSCALE: 1:24,000

/

N

72

Figure 25-- Distribution of copper normalized to iron (extracted usingoxalic acid) in -30 mesh stream sediment samples upstream ofsample AJ003S (concentrations in parentheses)

¡- iL-N

4:,10(t71) )1.l

4391

\\(2.56)11

148(j.38) 1499 Iba/.(1.85)

154(2.39);50(2.50) ,rTba ( 15301

i

.1

Iba \ --`" .QaN 42(1.65)

2000 FEETSCALE: 1:24,000

N

73

Figure 26-- Distribution of copper normalized to iron (extracted usingoxalic acid) in -30 mesh stream sediment samples upstream ofsample AJ039S (concentrations in parentheses)

74

Most of the anomalous copper is held in a reducible form

(probably iron or manganese oxides), although significant copper

does occur in a oxidizable form in the heavies and slimes (probably

organics, but possibly sulfides). The source of the anomalous

copper occurs ubiquitously throughout the anomalous areas because

copper does not change concentration upstream. Although the north-

western anomaly does have a spatial association with northerly

trending normal faults, the source of the copper cannot be traced

solely to these structures because of the ubiquitous nature of the

anomaly.

INTERPRETATIONS FROM HEAVY MINERAL CONCENTRATES

During the main phase of sample collection, heavy mineral

concentrates were collected at each sample site for a total of 78

samples. Replicate samples were collected at four sites to confirm

anomalies shown in the main phase of sample collection. After

preparation, the non -magnetic heavy mineral fraction was analyzed

using semi -quantitative emission spectroscopy, and its mineralogy

was examined visually. Sulfide grains were extracted from the sam-

ples and analyzed for copper with a microprobe. Finally, the C -1

and C -2 (magnetic) fractions were analyzed for copper using the

nitric acid extraction. The methods used, results, and interpreta-

tions of this part of the study are discussed in this chapter.

Field Methods

As with stream sediments, samples were composited along a

100 foot reach of the drainage and passed through a 5 mm sieve in

the field. Between 1500 and 3500 g (usually 2000 to 3000 g) of

sample were collected. As no water was present in the field area,

samples were taken elsewhere and panned to remove the bulk of the

light minerals (e.g. feldspar and caliche). For efficient panning,

fines were removed from the sample by kneading and washing. Samples

were panned down so their dry weight was between 50 and 200 g. The

samples were then taken to the laboratory for further preparation.

75

76

Sample Preparation

The panned samples were sieved through a 30 mesh screen;

the +30 mesh material was discarded. Heavy minerals were then

separated using bromoform (s.g. = 2.90). The lights were discarded.

The heavies were split into three magnetic fractions with a hand

magnet and a Frantz Isodynamic Magnetic Separator (front slope =

5 °; side slope = 10 °). Table 8 gives the setting and typical

mineralogy of each fraction. The minerals listed in the "C -3"

fraction include all the minerals observed during the study.

Table 8 -- Magnetic fractions and representative mineralogy

Fraction Range (amps)

C-1 <0.2

C-2 0.2 - 0.6

C -3 <0.6

Mineralogy

Magnetite and ilmenite

Pyroxenes, amphiboles, olivineand iron oxides

Sphene, zircon, apatite, pyrite,chalcopyrite, covellite, arsen-opyrite, galena, barite, cerus-site, wulfenite ( ?), cassiter-

ite, copper carbonates, lead shot,caliche fragments, rock frag-ments and pyroxene

The presence of caliche fragments and pyroxenes in the C -3

(non- magnetic) fraction indicates that the process is not 100%

efficient. The presence of lead shot points out one other signifi-

cant problem with this kind of a study: contamination due to cultural

activities.

Of the three fractions the C -1 and C -2 fractions had the

greatest mass. Masses of the C -1 fraction ranged from 0.61 to 31.88

g, while those of the C -2 fraction ranged from 0.53 to 12.40 g.

77

The C -3 fraction has the least mass; it ranged from 0.04 to 1.29 g.

Both the C -2 and C -3 fractions were split. One split from

each fraction was pulverized; the C -3 fraction was hand pulverized.

The C -1 fraction of ten samples was also pulverized.

Analysis of the C -1 and C -2 Fractions

The pulverized splits of the C -2 fraction, and the pulver-

ized C -1 fraction of ten samples were analyzed using hot nitric

acid. The results of the analysis are given in Appendix IIIc.

Figure 27 and Plate 11 depict the frequency and areal distributions,

respectively, for copper in the C -2 fraction.

As with the stream sediments, this sample medium shows a

bimodal distribution, implying possible background and anomalous

populations. The modes occur at 15 ppm and 50 ppm.

However, the areal distribution is slightly different. If

40 ppm or more is considered anomalous, the northwestern and north-cen-

tral anomalies merge into one continuous anomaly with rather erratic

highs. Moreover, anomalous values do not extend as far to the

east, and an anomaly in the south -central area appears. As with

other sample media, the values fade off to the southeast.

Of possible greater significance, the values reported for

this analysis range from 30 to 260 ppm in the C -1 fraction and 15

to 100 ppm in the C -2 fraction. As shown in the previous chapter,

the concentrations of copper using the same nitric acid extraction

in the heavies and the slimes separated directly out of stream

sediments (i.e. without washing away the fines) ran upwards to

VALUE

(PPM)

1- 10

11- 20

21- 30

31- 40

41- 50

51- 60

61- 70

71- 80

81- 90

91 -100

0

FREQUENCY10 15 20 25

78

Figure 27 -- Histogram showing the distribution of copper (extracted usinghot nitric acid) in the C -2 fraction of heavy mineral concen-trates

79

1000 ppm copper. Obviously, the values observed in the C -1 and C -2

fractions cannot explain the high values of the stream sediment

heavies. Therefore, the copper must occur in some other form--

in either the C -3 fraction or in the fines washed away during the

panning process. The lost fines are the better candidate for two

reasons. First, due to its relatively small mass contribution, the

C -3 fraction cannot produce the required copper (in fact, analyses

of this fraction indicate maximum concentrations of copper to be

300 ppm). Second, the slimes --which would have been washed away

during panning --also have high concentrations of copper. Therefore

the lost fines probably contain high concentrations of copper to

account for the copper in the heavy fraction of stream sediments.

Spectroscopic Analysis of the C -3 Fraction

The C -3 fractions of all 78 initial samples and four repli-

cate samples were analyzed for 31 elements using semi- quantitative

emission spectroscopy. Because different weights of sample were

used in the analysis, the detection limits are different. The

results of this analysis and the detection limits are presented in

Appendix Ic.

The four replicate samples were collected in order to confirm

anomalies found in the original 78 samples. Replicate sample pairs

are listed in Table 9. In all cases, the anomalies were confirmed;

however, the replicate values did fluctuate significantly from the

original values. One of the most severe problems with the type of

sample is the high variation of values in samples collected at the

80

Table 9-- Replicate heavy mineral concentrate sample pairs

AJ011C - AJ132C

AJ013C - AJ128C

AJ090C - AJ127C

AJ105C - AJ117C

same site. This is due both to the small size of the analytical

sample (5 mg) and to the small amount of sample actually realized

when preparation is finished. These problems should be considered

when reading this or other studies using the non -magnetic fraction

of heavy mineral concentrates as a sample medium. The distribution

of copper and other economic and economically -related elements are

discussed in the following section.

Copper

Both the frequency and areal distributions of copper in the

C -3 fraction of heavy mineral concentrates (see Figure 28 and Plate

12, respectively) differ from those in the whole stream sediment.

The correlation coefficient between these two sample media is only

0.4395 for copper. The frequency distribution for this medium is

unimodal, with the mode occurring at 70 ppm. Assuming the top 10%

of the values to be anomalous, the threshold is 200 ppm.

With this threshold, the anomalous values of copper occur

without any systematic order. However, if a cutoff of 150 ppm

were used (this includes 63% of the samples), the northwestern two -

thirds of the study area would be anomalous. This area would be

consistent with --but much larger than --the anomalous areas observed

with stream sediments.

This sample medium does not enhance the values observed in

stream sediments. The high values reported in both media are about

81

VALUE

(PPM) O

N(2)

L (2)

2

3

5

7

10

15

20

30

50

70

100

150

200

300

FREQUENCY5 10 15 35 40

JFigure 28 -- Histogram showing the distribution of copper in the non-

magnetic fraction (C -3) of heavy mineral concentrates

82

300 ppm. Therefore, the minerals in the C -3 fraction cannot be the

major cause of the anomalies observed in stream sediments. The

distribution observed is consistent with known anomalies, but it

does not enhance them in any way.

Other Elements

A totally unexpected result of this study is the discovery

of significant anomalous values for other interesting elements besides

copper in the non - magnetic fraction of heavy mineral concentrates.

Plate 13 shows the distribution of anomalous values (upper 10 to

15% of reported values) of silver, arsenic, barium, copper, molybden-

um, lead, antimony, tin and zinc. Figures 29 through 36 show the

frequency distributions of these elements (except copper).

The distribution of anomalous values is rather widespread

within the study area. To pick out possibly significant anomalies,

the clustering of anomalous values of elements with similar geochemi-

cal associations was used as the primary criterion. Based on this,

three anomalies were considered most significant.

The first anomaly, located in the northwest portion of the

study area, consists of a tight grouping of three samples with

anomalous values of molybdenum and tin. Of the three anomalies,

this one has the easiest explanation. The samples come from washes

that drain the Childs Latite in the area that alteration was ob-

served. The Childs Latite has also produced anomalous tin in other

parts of the Ajo 1° by 2° quadrangle (P.K. Theobald, personal commu-

nication, 1983).

VALUE FREQUENCY(PPM) 0 5 10 70

N(O.2)

L(O.2)

0.20.30. 50.7

1

1.52

3

57

10

15

2030

3

J

Figure 29 -- Histogram showing the distribution of silver in the non-magnetic fraction (C -3) of heavy mineral concentrates

t l

VALUE FREQUENCY

(PPM) 0 5 10 70 75

N(1OO)

L(1OO)

100150

200300500700

83

Figure 30-- Histogram showing the distribution of arsenic in the non-magnetic fraction (C -3) of heavy mineral concentrates

VALUE FREQUENCY(PPM) 0 5 10 15

N(50)

L(50)

50

70

100

150

200

300

500

700

1000

1500

2000

3000

5000

7000

10,000

.J

jFigure 31 -- Histogram showing the distribution of barium in the non-

magnetic fraction (C -3) of heavy mineral concentrates

VALUE FREQUENCY(PPM) 0 5 10 65 70

N(10)

L(10)

10

15

20

30

50

70

100

150

200

J

3

3

84

Figure 32 -- Histogram showing the distribution of molybdenum in the non-magnetic fraction (C -3) of heavy mineral concentrates

85

VALUE FREQUENCY(PPM) 0 5 10 15 20 25 30N(5)L ( 5)

5

7

10

15

2030

5070

100

150

200300500700

100015002000

3

I

I

Figure 33 -- Histogram showing the distribution of lead in the non -magiñetic fraction (C -3) of heavy mineral concentrates

VALUE FREQUENCY(PPM) 0 5 10 70 75

N(20) l=1L(20) J20305070

100 3

Figure 34 -- Histogram showing the distribution of antimony in the non-magnetic fraction (C -3) of heavy mineral concentrates

86

VALUE

(PPM)

N(10)

LOO)

10

15

20305070

100150

200300500700

1000

FREQUENCY0 5 10 15 20 25 30 35

J

J

J

JFigure 35 -- Histogram showing the distribution of tin in the non-

magnetic fraction (C -3) of heavy mineral concentrates

VALUE

(PPM)

N(100)

L(100)

100150

200300500

FREQUENCY

0 5 10 75 80

J

Figure 36-- Histogram showing the distribution of zinc in the non -magnetic fraction (C -3) of heavy mineral concentrates

87

The second anomaly, defined by a clustering of four sample

sites showing high values of the volatile elements arsenic and anti-

mony with lesser copper, molybdenum and tin, occurs in the north -

central part of the study area. Of the four sites, two were re-

sampled, confirming the anomaly. A contiguous sample also contained

grains of chalcopyrite and covellite (see next section) although only

70 ppm was reported in the analysis. No geologic expression of the

cause of the anomaly was observed by traversing the drainage. But

owing to colluvium on the walls of the canyons, any alteration pre-

sent could easily be missed. The anomaly deserves follow -up work

in the future.

The final anomaly, located towards the southeast, consists

of a group of six samples showing high values of silver, molybdenum

and arsenic. This anomaly is the most obscure because its cause

was not seen on the ground or during visual examination of the

samples (with the exception of one sample which contained arseno-

pyrite).

Apart from the three anomalies just described, other samples

could be considered anomalous. However, they are not discussed

because they do not meet the previously described criteria.

Mineralogy of the C -3 Fraction

To determine the sources of metals in the non -magnetic frac-

tion, the non -pulverized split of each sample was examined under

the binocular microscope to determine the minerals present. Ore

88

and related minerals are commonly preserved in stream sediments under

conditions of rapid erosion.

This fraction contains sphene, zircon and apatite as the

dominant minerals. Pyrite, chalcopyrite, covellite, arsenopyrite,

galena, barite, cerussite, wulfenite ( ?), cassiterite and malachite

occurred in one or more samples. Other significant materials ob-

served in the samples include lead shot, caliche fragments, rock

fragments and pyroxene. Plates 14 and 15 show the distribution of

economically significant and related minerals.

From these data, two generalizations can be made. First,

pyrite occurs throughout the study area. Its widespread occurrence

implies pyrite is probably a minor accessory mineral in the Batamote

Andesite.

Second, high values of lead, bismuth, antimony and tin should

not be trusted. In three samples, lead shot was observed, raising

the possibility of contamination in other samples. Bismuth, anti-

mony and tin are common alloys in shot. Solitary high lead values

should be regarded with suspicion.

Other minerals reflect the analytical values to greater and

lesser degrees. Arsenic occurs as arsenopyrite; lead occurs as

galena, lead shot, cerussite or wulfenite; copper occurs as chalco-

pyrite, malachite and covellite; and tin occurs as cassiterite.

The second anomaly, as described above, is caused by the

presence of arsenopyrite, chalcopyrite, malachite and covellite. In

the third anomaly, only one sample contained arsenopyrite. Other

scattered mineral occurrences were observed through the study area.

89

The Concentration of Copper in Pyrite Grains

Pyrite grains represent a possible source of copper within

the heavies and therefore the stream sediments. To test this hypoth-

esis, pyrite grains were extracted from seven samples and analyzed

for copper using a microprobe. During this analysis, other minerals

besides pyrite were found. Although the majority of the grains did

turn out to be pyrite, grains of rutile, chalcopyrite, arsenopyrite

and covellite were also analyzed. The results of this analysis are

given in Table 10. The galena grain was analyzed to determine its

identity.

Of the samples analyzed, two are considered anomalous (based

on copper values in stream sediments), two samples are considered

borderline anomalous and three samples are at background. Although

some pyrite grains in the anomalous samples did contain significant

copper (up to 3400 ppm), the average grain from the anomalous

samples did not contain significantly more copper than grains from

the background samples. Therefore, the copper held in pyrite cannot

explain the anomalous copper present in stream sediments.

Summary

The distribution of copper in the C -3 fraction of heavy

mineral concentrates reflects that in the stream sediments in a very

general way. The northwestern anomaly shows up when the threshold

is 150 ppm; however, at this threshold 63% of the samples would be

considered anomalous. More importantly, the anomaly is not enhanced

90

Table 10-- Concentrations of copper in pyrite grains from selected heavy

Sample

mineral concentrate samples

Grain Concentration (percent)Cu Fe S As Pb Total Mineral

AJ029C 1 0.000 47.833 53.973 -- 101.806 PY2 0.010 47.358 53.912 -- 101.279 PY3 0.023 47.921 53.967 101.911 py

4 0.071 48.136 54.030 102.236 PY5 0.000 47.934 53.854 101.789 PY6 0.014 47,753 54.256 102.024 PY7 0.113 48.093 54.214 -- 102.240 PY

0.049. 47.917 54.181 -r- -- 102.146

0.091 47.433 53.962 -- 101.486

8 0.040 47.591 54.197 -- 101.827 PY9 0.029 47.715 54.012 - 101.757 PY

AJ037C 1 0.000 47.499 51.940 99.389 1Y2 0.002 47.568 52.596. -- 10-0.166 PY3 0.141 46.634 51.643 -- 98.419 PY

0.341 46.588 53.688 100.617

0.072 46.322 52.654 99.058

4 0.002 47.619 53.949 101.571 py

AJ056C 1 -- - ru

2 30.689 30.774 34.837 96.300 cp

3 64.709 0.038 27.654 92.401 cv

4 ' 0.00.0 47.814 53.65.1 101.465 py

AJ069C 1 0.003 46.558 53.003 . 99.563 py

2 0.035 47.327 53.188 100.549 py

3 0.023 47.191 53.7.11 -- 100.9.26 py

4 0.007 48.057 53.927 -- 101.991 py

AJ076C 1 0.006 47.980 54.020 -- 102.005 py

2 0.000 35.592 22.82.1 40.938 99.351 as

3 0.013 35.744 23.001 40.971 99.778 as

4 0.000 35.240 20.775 40.934 -- 96.949 as

5 0.006 35.367 22.533 40.909. 98.815 as

AJ077C 1 0.011 46.751 53.557 100.319 py

2 0.001 47.412 53.562 100.975 py

3 0.000 47.077 54.078 10.1.155 py

4 0.026 47.210 53.879 10.1.166 py

AJ091C 1 -- -11.177 -- 83.870 95.047 gn

2 0.000 46.289 54.018 100.307 py

3 0.000 47.892 53.832 -- 10.1.724 py

91

relative to stream sediments in this fraction, implying that this

fraction is not the primary source of copper in the anomalous areas.

The low values of copper in the C -1 and C -2 fractions preclude

them from being a significant source of anomalous copper. This

suggests that the bulk of the copper present in the heavy fraction

of stream sediments could occur in fines that were washed away during

the panning process. The high copper values in the slime fraction

of the stream sediments supports this assertion.

Copper is not held to a significant degree in pyrite, which

implies the copper held in a reduced form probably occurs as organics.

Since the slimes would be expected to contain organics in preference

to sulfide, the high concentrations of oxidizable copper (along with

relatively low concentrations of reduced iron) in the slimes support

this hypothesis.

The most intriguing results of this part of the study are the

presence of high concentrations of volatile and base metals in

certain parts of the study area. Of the three anomalies defined by

heavy mineral concentrates, only one has a ready explanation.

OTHER RESULTS

As a test of the hypothesis that the anomaly could be caused

by dispersion from material within or related to the normal faults,

samples containing oxide coatings along fractures or broken zones

within the Batamote Andesite were collected in both anomalous and

background areas. Three samples (AJ136R, AJ152R and AJ155R)

were collected in areas considered to be anomalous, and six samples

(AJ162R through AJ167R) were collected in areas considered to be

background (see Plate 2 for locations). The oxide coatings were

removed using a hot oxalic acid leach and analyzed using semi -

quantitative emission spectroscopy. The results are tabulated in

Appendix Id.

Because the anomaly of interest is comprised of high values

of copper, silver and bismuth, this discussion will concentrate on

these three elements. Of these, copper and bismuth showed a signifi-

cant enrichment in the samples collected the anomalous area. Copper

is enriched by factors ranging between 6 and 20, and bismuth is en-

riched by factors between 20 and 50. This indicates that these

coatings are possible sources of bismuth and copper in anomalous

stream sediments.

However, silver is concentrated in the samples from non -

anomalous areas by factors up to 15. But the highest concentrations

of silver also come from a drainage area that has high silver in

92

93

heavy mineral concentrates --part of the third anomaly discussed in

the previous chapter.

Other elements that show some enrichment in the samples from

anamalous areas include arsenic, beryllium, antimony and tin.

Therefore the enrichment of these elements -- espically copper

and bismuth --lends credence to the hypothesis that the anomalous

copper values were derived from dispersion from normal faults and

fractures within the northwestern part of the study area.

On sample AJ136R, oxides as "limonite" extend into the rock

for up to one cm. The silicate minerals within this zone were not

altered to a greater extent than in the rest of the rock. However,

calcite was observed in the zone in addition to the oxides. The

lack of alteration of silicates in this zone indicates that the

,waters that deposited the copper and bismuth in this crack were

relatively cool.

SUMMARY OF DATA PRESENTED,EVALUATION OF WORKING HYPOTHESES, AND CONCLUSIONS

The distribution of trace elements (principally copper,

silver and bismuth) in stream sediments and rocks of the Batamote

Mountains was examined in this study to determine the cause of

anomalous values of copper reported in earlier studies.

The Batamote Andesite has a copper concentration of around

30 ppm, which is relatively low for rocks of similar compositions.

The values of copper have a very tight distribution, implying that

copper has a homogeneous distribution throughout the unit. The

Batamote Andesite is the predominant bedrock in the study area,

so its copper concentration must control background copper concen-

trations in stream sediments from washes draining the mountains.

Analysis of stream sediments defined two anomalous areas

within the Batamote Mountains, which are characterized by the suite of

copper, bismuth and silver. The most significant anomaly, located in

the northwestern part of the study area, has a distinct spatial asso-

ciation with a series of northerly trending normal faults. The

second anomaly, located in the north -central part of the study area,

has no obvious lithologic or structural control. In several of the

chemical extractions, a definite trough separated the two anomalous

areas; however, in other extractions and sample media, the two

anomalous areas merged together, suggesting that they might be

part of one larger anomaly. Since copper values do not vary

94

95

significantly upstream of anomalous sample sites, the input of

anomalous material comes from throughout the drainage basin; there-

fore, anomalies cannot be traced to a localized source.

Detailed sequential extractions imply that the copper in

anomalous samples is held dominantly in a reducible state although sig-

nificant copper is held in an organic or sulfide state in the heavies

and slimes of stream sediments. Values of copper in all fractions of

heavy mineral concentrates cannot account for the values observed

in the heavies and slimes of stream sediments. Since fines are lost

during the panning process, this material could contain the missing

copper. In fact, the high values for slimes support this hypothesis,

as they would tend to be washed away during panning.

Analysis of pyrite grains extracted from the non -magnetic

fraction of heavy mineral concentrates demonstrates that coarser

grained sulfide cannot account for the copper anomalies observed

in any sample medium.

Analysis for other elements in the non - magnetic fraction

of heavy mineral concentrates produced three other anomalies not

related to the stream sediment anomalies. One anomaly, character-

ized by tin (cassiterite) and molybdenum, occurs in an area where

extensive alteration was observed in the Childs Latite. The other

two anomalies, characterized by arsenic and antimony, and silver,

molybdenum and arsenic, respectively, remained unexplained. No

alteration, other than the presence of chalcedony and zeolites, was

observed in these two areas.

Finally, analysis of oxide coatings from fractures in both

96

anomalous and non -anomalous areas (as determined from stream sedi-

ments) show that oxide coatings in anomalous areas contain signif i-

cantly more bismuth and copper than those in non -anomalous areas.

Evaluation of Working Hypotheses

In the introduction to this paper, five working hypotheses

were presented as possible explanations for the anomalies observed

by Barton and others (1982). In this section, each hypothesis is

reviewed in the light of the data generated by this study in order

to determine its relative merit.

Airborne Contamination from a Smelter in Ajo

This hypothesis calls upon wind blown smelter dust from Ajo

as the source of copper. This mechanism is unlikely because the

anomaly does not decay significantly downwind from the smelter

(anomalous values occur on both sides of the Batamote Mountains),

and the coarser fractions contain anomalous values of copper

(smelter dust is very fine grained). Therefore, this mechanism

probably did not cause the observed anomalies, although it cannot

be ruled out due to the immense amount of copper that went up the

stack of the Ajo smelter.

Abnormally High Background in the Batamote Andesíte

Another possible source of copper is the rock unit that the

washes drain. However, analysis of samples of the Batamote Andesíte

give a background value of around 30 ppm for copper. Since anomalous

values in stream sediments range upwards to 280 ppm, this mechanism

is impossible.

97

Primary Mineralization

Primary hydrothermal mineralization alone could not account for

the broad copper anomalies observed in the stream sediments. Yet, it

best explains the three anomalies observed in heavy mineral concen-

trates. The minerals that cause the anomalies include primary minerals.

But in two of the anomalies, evidence for primary mineralization

was not observed on the ground.

Dispersion Along Normal Faults

Most evidence presented in this paper suggests that the best

explanation for the anomalies observed in stream sediments is that

they were produced as the result of dispersion of metals from oxide

coatings in faults and joints in the northwestern part of the study area.

Two principal pieces of evidence point to this mechanism. First, the

anomalous values have a definite spatial association with the normal

faults. Second, analysis of oxide coatings from fractures in the anoma-

lous areas indicate that they have concentrated both copper and bismuth

relative to oxide coatings in fractures from non -anomalous areas.

On the other hand, the fact that entire drainages contribute

significantly to the anomalies implies that the actual faults were

not the only contributors to the anoalies. Mineralized fractures

and joints within the northwestern faulted block also probably

contributed significant metals.

The evidence presented to this point ties the source of

metals in stream sediments to oxide coatings in faults, joints and

fractures in the northwestern section of the study area. However,

98

a more basic and interesting problem remains to be solved: the

original source of metals in these structures. Clearly, the metal

in the faults, joints and fractures is the result of secondary or

even tertiary disperson from some other source.

Possible sources of the metals in the faults, joints and

fractures include: 1. Unusual weathering processes that somehow

concentrated metals from background andesite into weathering rinds

along openings in the rock; 2. A higher water table that allowed

groundwater to deposit the metals; 3. Solutions migrating from the

New Cornelia Deposit; and 4. An upper -level hydrothermal system in

the Batamote Andesite that deposited metals that were subsequently

concentrated into the oxide coatings. This should not be consid-

ered an exhaustive list, as many other mechanisms could be called

upon to deposit the metals; however it does include the most reasonable

(in the author's view) possibilities for a source of metal.

Weathering can and does produce oxide coatings that signifi-

cantly concentrate metals relative to their host rock. However,

oxide coatings from, the anomalous area contain significantly more

copper and bismuth than those from the background. Presumably,

weathering of the Batamote Andesite could not account for the great

differences in metal concentrations observed, and it could not

produce the observed distributions.

If a higher water table existed in the recent geologic past,

solutions enriched in metals leached from rock below could provide

the metals observed in the oxides. The original source of the metals

would have had to be relatively close, possibly directly below, the

99

observed anomaly. This would be a reasonable mechanism to produce

the metals in the faults, joints and fractures.

The third possibility, lateral migration of supergene

solutions from the New Cornelia orebody, is unlikely because of the

long distances involved (up to 10 miles), and because the observed

metal assemblage in the stream sediments (Cu- Bi -Ag) differs from

that observed around the orebody (Cu- Mo -Pb) (P.K. Theobald, personal

communication, 1984). Therefore, this mechanism is considered

unlikely.

The fourth alternative in which the primary metals were

deposited by the distal portion of a hydrothermal system and then

weathered and deposited into oxide coatings in faults and joints, is

considered the best possibility for several reasons. First, although no

extensive hydrothermal alteration is present in the Batamote Andesite,

evidence for hydrothermal circulation does exist. Chalcedony fills

joints and fractures throughout the unit, and a "limonite" multi -

spectral imaging anomaly exists around the intrusive plug. It is

not unreasonable that a hydrothermal cell developed during or shortly

after the volcanism that produced the Batamote Andesite.

Second, the anomalies observed in the heavy mineral concen-

trates are best explained as the results of hydrothermal activity.

The arsenic- antimony anomaly observed in the north -central

section of the study area would be best explained as the result

of primary low temperature hydrothermal circulation. The scattered

base metal anomalies could also be produced by hydrothermal activ-

ity. Therefore, a distal hydrothermal system could provide the

100

necessary metal as sulfide, which in turn could be weathered and

redeposited into faults, fractures and joints as oxides.

It should be remembered that the above discussion is only

speculation about the source of the metals in the faults --none of

the hypotheses presented could be confirmed by this type of a

study. They should be regarded as working hypotheses for future

investigations. Based on the data presented, the only conclusion

that can be made is that the observed anomalies are best explained

as dispersion into stream sediments from metals tied up with

faults, fractures and joints in the northwestern section of the

study area.

Contamination of the Batamote Andesite During its Eruption

The mechanism involving contamination of the Batamote An-

desite before or during its eruption is also unlikely. The back-

ground values for the Batamote Andesíte are too low to allow total

assimilation of the contaminant to be a cause. Additionally, the

copper values show no zonation relative to the central vent from

which the unit was extruded as might be expected from contamination

without assimilation. Therefore this mechanism is considered

unlikely.

Conclusions

At least two processes were involved in the production of the

observed anomalies: primary mineralization and dispersion along

normal faults. The anomalies observed in the non -magnetic fraction

of heavy mineral concentrates are best explained as a result of

101

primary mineralization. The minerals observed in this fraction

include primary sulfides of copper, lead and arsenic. These minerals

usually occur in hydrothermal environments.

The copper- bismuth -silver anomalies observed in stream

sediments are best explained as the result of higher order dispersion

from metal held as oxide coatings along fractures and joints.

The original source of the metals that were deposited in the oxide coat-

ings still remains unresolved. Viable possibilities include ground-

water solution and deposition and distal hydrothermal activity in

the Batamote Andesíte. Assuredly, these are not the only possibil-

ities, but they can serve as models for further exploration in the

area. Given the location of the study area within the porphyry

copper belt of southwestern North America and the requisite size of

the original copper source to produce such a widespread anomaly, the

potential for a porphyry copper deposit buried in the subsurface

below the Batamote Andesite as the original source of metals exists.

This potential is enhanced by the presence of a magnetic dipole coin-

cident with the copper- bismuth -silver anomaly presented in this paper

(Klein, )982). Additionally, the anomaly lies along the Jemez lineament,

upon which the New Cornelia and Casa Grande West porphyry copper depo-

sits lie. Therefore a potential for porphyry copper mineralization

exists below the Batamote Mountains.

APPENDIX Ia

ANALYTICAL RESULTS (USING SEMI -QUANTITATIVE EMISSION SPECTROSCOPY)

FOR ROCK CHIP SAMPLES, BATAMOTE MOUNTAINS, ARIZONA

102

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C.

° Gü r{ro.4.4 .r1 O .r{ .1-'1 r{ ,a U r1 .r1U) +-1 1.1 U) 4.4 1.+ U) U U) U)Cl.) ct! U) a) cd ro a) a) a) a)

G4.-4 4-4 GG c 7:).

ro u ro cd u u a1 it ror-Í U) r! r! U.

i-i +-1 U 4)-1 4-1 ).4 ri U UCO ri U rl ri r-! CK 1.1 ri rirti }-I rd 1J í4 i.d rI ri 14 4-J

U .0 U) CO ,.0 .-O U ro ro ror1 a. Cd Cl) ß. G. ri r-1 Cl) U;

CO i-, r-i Cd }-+ 3-i U) CG Cda) O u z o o a) "a Pa Aa> Pa

GPa Pa > Ñ

Cd rlU r-ir-{ r-iO ri> bC

e

x x 6 x xin co orO'r0Or 0 0 0 *-iO -4 H66666

xxxxxH N M

.--{H H H6666

104

.. CD 4 4 4 z 4 4 4,4 4 4 4 4 0 4 4 4 4 4 0 0 4 0 4 4N N N N NCL

z 4 z z z z Z Z z z z z z z z Z Z Z Q Z z z Z Z zo E .-.

. o o 0 0 0 O O O C O 0 0 0 0 0 O o 0 0 o C O o 0 0C1 E u, C O O N r- it1 n ul r- O u1 n r- O O n r, c O n un N r- n

ß. .-o .-i -o --rP.

.. Oo00ir1 O O O O O O u, -oinO OcunO 4 0 400M un ul M N N M u1 N ul ,o N N ct1 M M N

U CLCL

0 0 ul 0 2i 0 0 0 0 0 O O O Zun O Z O O Z z o z O ocf1 01 N M 01 ul O^a N N N N N u1 un un N

U O. ,-4 .-i

i-. O O O C Z C O O O O O O O Z C 0 4 4 0 Z Z O Z O Oo E N r1 N cV N N N M N-+ fV -- M N M CA CVC..) a

CL

ZzzZZ ZzzzZ ZzZZZ zzzzz zzZZzb EC.) a.,a

oa

..

CL.

ER.a._,

,.E

CL

.

Eß+a

zzzzz

oo un un u1 Zoo --i oo

O O o O OO O O O OO O O

,-a

0 0 0 0 0N N Noo un

zzzzz

un -+ un ,--r N

o 0 0 o OO O O O Oul r- en M u1

O O O O ON N N N N

zzzzz

N ul u1 n ul.

0 0 0 0 0O O O cn Or- u-) n n

O O O c 0N N ul N

zzzzz zzzzz

..,

. zzzzz ZzzzZ zzzzz zzzzz zzzzz-4 p.a

w xxxxx o4xo4 wrx x<4oaxx o4x<4Foz o4xxrxxr i 7 O\ ,so qD r, Co O 7 '-+ r1 vO in Co On 01 O .-o N M 7 unG. O O O N N 7 7 7 ul ul qD r, n r, oo O O O'--1 r-+ -+ .-+ --rE 0 0 0 0 0 O O O_ O O O O O O O O-+ -+

< 6 4 < 4 < < 4 <4 6 <4 <4 <4 <4 <4 <4 <4 <4 <4 <4 <4 <4 <4 <4

Appendix Ta -- continued

Sample

Ni

(PPm)

Pb

(PPm)

Sb

(PPm)

Sc

(PPm)

Sn

(PPm)

Sr

(PPm)

V

(PPm)

W

(PPm)

Y

(PPm)

Zn

(PPm)

Zr

(PPm)

Th

(PPm)

AJOO4R

50

20

N10

N500

100

N10

L70

N

AJOO6R

50

30

N20

N500

100

N50

L300

N

AJOO9R

20

30

N15

N500

70

N50

L200

N

AJ025R

15

20

N15

N500

70

N50

L200

N

AJ026R

NL

NN

N200

LN

NN

30

N

AJ046R

30

15

N20

N500

100

N50

L200

N

AJ047R

20

15

N20

N500

70

N50

L200

N

AJ048R

30

20

N20

N500

100

N50

500

200

N

AJO5OR

70

10

N20

N500

100

N20

L100

N

AJ054R

10

20

N10

N500

70

N30

L200

N

AJ062R

20

30

N20

N500

100

N50

200

300

N

AJ071A

10

20

N10

N500

50

N20

L150

N

AJ071B

30

20

N20

N500

100

N30

L200

N

AJ073R

N30

NN

NN

NN

20

N50

N

AJ086R

20

30

N20

N500

100

N50

L200

N

AJ095R

50

20

N20

N500

100

N50

1000

200

N

AJ108R

N20

N5

N300

50

N20

L200

N

AJ109A

15

30

N5

N2000

50

N20

N100

N

AJ109B

50

20

N20

N500

100

N50

L200

N

AJ11OR

N20

NN

NL

NN

30

N100

N

AJ111R

N20

NN

NN

NN

30

N70

N

AJ112R

70

10

N20

N500

100

N30

L50

N

AJ113R

N10

NN

NN

NN

30

N50

N

AJ114R

50

10

N15

N500

100

N30

L200

N

AJ115R

30

10

N15

N500

100

N30

L150

Nó ui

Appendix Ia-- continued

Sample

Description

Fe

(%)

Mg

Ca

Ti

Mn

(PPm)

Ag

iPPm)

As

OPm)

AJ116R

Latite

21

1.5

0.3

700

NN

AJ118R

Basaltic andesite

31

1.5

0.3

1000

NN

AJ119R

Intrusive andesite

31.5

1.5

0.3

1000

NN

AJ12OR

Basaltic andesite

31.5

1.5

0.5

1000

NN

AJ121R

Intrusive andesite

52

20.5

1500

NN

AJ122R

Intrusive andesite

32

20.2

1000

NN

AJ123R

Vesicular andesite

52

20.3

1000

NN

AJ124R

Basaltic andesite

51

1.5

0.5

1000

NN

AJ125R

Basaltic andesite

31

1.5

0.5

1000

NN

AJ126R

Vesicular andesite

31

20.5

1000

NN

AJ129R

Hydrothermally breccíated andesite

21

1.5

0.3

1000

NN

AJ13OR

Chalcedony

0.2

0.02

0.1

0.03

300

NN

AJ131R

Basaltic andesite

51

1.5

0.3

1000

NN

AJ133R

Vesicular andesite

51

1.5

0.5

1000

NN

AJ134R

Basaltic andesite

51,5

1.5

0.5

1000

NN

AJ135R

Basaltic andesite

51

1.5

0.5

1000

NN

AJ137A

Caliche

0.5

120

0.05

200

NN

AJ137B

Basaltic andesite

31

1.5

0.5

1000

NN

AJ137C

Caliche

0.3

120

0.05

100

NN

AJ137D

Caliche

0.3

120

0.05

100

NN

AJ138R

Basaltic andesite

21

1.5

0.3

1000

1N

AJ139R

Vesicular andesite

71.5

20.5

1000

NN

AJ14OR

Vesicular andesite

51

20.5

2000

NN

AJ144R

Basaltic andesite

51

1.5

0.5

1000

NN

AJ146R

Vesicular andesite

31.5

1.5

0.3

1000

5N

1-, o rn

107

r- zaaaz zaaaa .4Z1-4 aa azazZ .4a.4Ñaz áa

z Z z z z z Z z z z z z z ZZ z Z-+ z z z z z z z ZO á

C4..,

0 0 0 0 o O o o O O O o 0 0 0 o O O O O 0 0 0 0 0R1 E u1 u1unO1.01 u1u10rrO r,N O O O ONONN 0, 000r-a a rl 1-1

r`0000 00000 un,.aoo0 COOr,O 00 000N 01 M t, 01 cYi CYf N M N c+l 01 N N C'1 M c'') N NU

.. zoo 00 000oo OZO00 0001-4Z OOOOLnE N N N O O O *-4 4--1CV ,4 CJ CJ N Cr) NNr !a CV

...

00000 000u10 O Zirlul0 o Zu1Z z ul0 0u1u1O e ,- .-i N N un N c+1 N N N N --i ,4 cV CV -- r-!U aa...

"ti EZZZZZ ZZZZZ ZZZZZ ZZZZZ zzZZz

U

aa a..,

vw

cQ EPa a

-.E

Z z Z Z Z

u, u1 a.

0 0 0 0 000000CY1 u1 u1 u1 c1

00000CV 0,1 N

Z Z Z z Z

ra u1 i.n irl-; -

0 0 0 0 000000N 01 u1 u-1 t.

o0ooun.. N.-+ 4--+

z z Z Z Z

r+ Z u> irl u1

0 0 0 0 000000ul -+ u1 u1 r

00000C"1 cV -+ N N

Z z Z Z Z

u, Z u1 Z Z

0 0 0 0 0O u100 0u1 -+ u1 N r+

0,..ao.4oN N '--i

Z Z z Z Z

r+ u1 u1 u, r+- -

0 0 0 0 0CD CD 000r` O r t\ O

--+

00000N N N C1 N

Z Z Z Z Z Z Z Z z Z Z Z Z Z Z Z Z Z z Z Z Z Z Z Zá

N C4 P~ A4 P4 M Pa P4 P4 P; ß: P: P.', 04 P' P; P4 <C PI C U Q P; P4 P4 ß+ P4r-1 q D CO CT O r-+ N C1 t u1 q O CT O--+ ce) ,T ul r, r` r` 0, 00 on O-43 OCL - .-+ 4-4 N N N N N N N N M 01 on 01 01 01 C*1 CY} CM on c¡l -d- ,fE .. .. .. .-. .-a .. ,. .-4 .. .-r ...I --.1 .. .4.4 .. F.-1 F-i 1--1 1-1 ,-1

1-.1 1-1 c 6¢

Appendix Ia -- continued

Sample

Ni

(PPm)

Pb

(PPm)

Sb

(PPm)

Sc

(PPm)

Sn

(PPm)

Sr

(PPm)

V

(PPm)

W

(PPm)

Y

(PPm)

Zn

(PPm)

Zr

(PPm)

Th

(PPm)

AJ116R

20

10

N5

N500

50

N10

L150

N

AJ118R

20

10

N10

N500

70

N20

200

150

N

AJ119R

20

10

N15

N500

70

N30

200

150

N

AJ12OR

20

20

N15

N500

70

N50

200

200

N

AJ121R

100

10

N20

N500

100

N20

L50

N

AJ122R

70

10

N20

N500

100

N20

L50

N

AJ123R

70

10

N20

N500

100

N20

L70

N

AJ124R

20

20

N10

N500

70

N30

L200

N

AJ125R

15

20

N10

N500

70

N30

200

200

N

AJ126R

15

20

N15

N500

70

N30

200

200

N

AJ129R

10

20

N7

N500

50

N20

L150

N

AJ13OR

NL

NN

N100

20

NN

N10

N

AJ131R

15

20

N15

N500

70

N30

L200

N

AJ133R

10

20

N15

N500

100

N30

L200

N

AJ134R

15

20

N15

N500

100

N30

200

200

N

AJ135R

20

20

N15

N500

70

N20

200

300

N

AJ137A

510

NN

N500

LN

30

L20

N

AJ137B

20

15

N10

N500

70

N30

200

300

N

AJ137C

L10

NN

N500

NN

LN

20

N

AJ137D

LL

NN

N200

LN

LN

20

N

AJ138R

15

10

N10

N500

50

N20

L200

N

AJ139R

20

20

N20

N500

100

N50

N300

N

AJ14OR

20

20

N15

N500

100

N30

L200

N

AJ144R

20

20

N15

N500

100

N30

L200

N

AJ146R

15

20

N10

N500

70

N20

L200

Nf,- o oo

Appendix Ia-- continued

Sample

Description

Fe

(%)

Mg

Ca

(%)

Ti

CZ)

Mn

íPPm)

Ag

(PPm)

As

(PPm)

AJ147R

Vesicular andesite

31

1.5

0.3

1000

LN

AJ151R

Vesicular andesite

51

20.5

1000

NN

AJ156R

Basaltic andesite

51

1.5

0.5

1000

NN

AJ157R

Vesicular andesite

31

1.5

0.5

1000

NN

AJ159R

Basaltic andesite

31

1.5

0.3

1000

1N

AJ160A

Basaltic andesite

51

1.5

0.5

1000

NN

AJ160B

Caliche

0.5

0.7

20

0.05

200

NN

AJ161R

Vesicular andesite

51.5

20.3

2000

1.5

N

Appendix Ia -- continued

Sample

Au

BBa

Be

Bi

Cd

Co

Cr

Cu

La

Mo

Nb

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

iPPm)

(PPm)

Wm)

iPPm)

(PPm)

(PPm)

AJ147R

N20

700

1N

N15

20

20

70

NL

AJ151R

N20

700

1.5

NN

20

50

30

100

NL

AJ156R

N10

700

1.5

NN

20

70

15

100

NL

AJ157R

N20

700

1.5

N20

30

20

100

NL

AJ159R

N10

700

1.5

NN

20

30

30

70

NL

AJ160A

N20

700

1.5

NN

30

50

30

100

NL

AJ160B

N10

300

NN

NN

10

15

20

NN

AJ161R

N20

700

1.5

NN

30

70

30

50

NL

Appendix Ia -- continued

Sample

Ni

Pb

Sb

Sc

Sn

Sr

VW

YZn

Zr

Th

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPn)

AJ147R

15

10

N10

N500

70

N20

L200

NAJ151R

20

20

N15

N500

100

N30

L200

NAJ156R

20

20

N15

N500

100

N30

L200

NAJ157R

20

20

N15

N500

70

N30

L200

NAJ159R

20

20

N15

N500

70

N30

L200

N

AJ160A

50

20

N15

N500

100

N50

L300

NAJ160B

510

NN

N300

LN

LN

30

NAJ161R

50

20

N20

N500

100

N50

N200

N

L = Detected at levels below the detection limit

N = Not detected at lower detection limit

Lower detection limits:

Element

Lower

Detection

Limit

Fe

MgCa

Ti

Mn

Ag

AsAu

B Ba

0.05 %

0.02 %

0.05 %

0.002 %

10 ppm

0.1 ppm

200 ppm

10 ppm

10 ppm

20 ppm

Element

Lower

Detection

Limit

Be

Bi

Cd

Co

Cr

Cu

La

Mo

Nb

Ni

1 ppm

10 ppm

20 ppm

5 ppm

10 ppm

5 ppm

20 ppm

5 ppm

20 ppm

5 ppm

Element

Lower

Detection

Limit

Pb

10 ppm

Sb

100 ppm

Sc

5 ppm

Sn

10 ppm

Sr

100 ppm

V10 ppm

W50 ppm

Y10 ppm

Zn

200 ppm

Zr

10 ppm

Element

Lower

Detection

Limit

Th

100 ppm

APPENDIX Ib

ANALYTICAL RESULTS (USING SEMI -QUANTITATIVE EMISSION SPECTROSCOPY)

FOR STREAM SEDIMENTS, BATAMOTE MOUNTAINS, ARIZONA

112

Appendix Ib -- Analytical Results (Using Semi -Quantitative Emission Spectroscopy) for Stream Sediments,

Sample

Batamote Mountains, Arizona

Fe

Mg

Ca

Ti

(%)

(%)

(%)

(%)

Mn

(PPm)

Ag

(PPm)

As

(PPm)

Au

(PPm)

B

(PPm)

Ba

(PPm)

Be

(PPm)

Bi

(PPm)

AJ001S

31

1.5

0.5

500

LN

N50

700

1.5

N

AJ002S

51.5

21

1000

LN

N50

700

1.5

N

AJ003S

31.5

20.5

700

LN

N100

700

1.5

L

AJ005S

31

1.5

0.5

700

LN

N70

700

1.5

L

AJ007S

51.5

20.5

500

0.2

NN

70

700

1N

AJ008S

31

1.5

0.5

500

LN

N70

700

1.5

2

AJOlOS

31

20.5

500

LN

N70

700

1.5

2

AJ011S

21

20.5

500

LN

N70

700

1L

AJ012S

31

20.5

500

LN

N70

700

1L

AJ013S

31

20.5

500

LN

N100

700

1.5

L

AJ014S

31

20.5

700

LN

N100

700

1.5

L

AJ015S

21.5

20.5

700

LN

N70

700

1L

AJ016S

21

20.5

700

LN

N70

700

1L

AJ017S

21

20.5

500

LN

N50

700

1L

AJ018S

31

20.5

500

LN

N70

700

1L

AJ019S

51.5

20.5

500

0.1

NN

70

700

1L

AJO2OS

31

20.5

700

LN

N50

700

1L

AJ021S

31

20.5

500

0.7

NN

70

700

12

AJ022S

31

20.5

500

0.5

NN

70

700

1L

AJ023S

31.5

20.5

500

0.2

NN

70

700

12

AJ024S

31.5

20.5

500

0.1

NN

70

700

1L

AJ027S

31.5

20.5

500

0.1

NN

50

700

1L

AJ028S

31.5

20.5

500

0.1

NN

50

700

1L

AJ029S

51

20.5

1000

0.1

NN

50

1000

1L

AJO30S

51.5

20.5

1000

0.1

NN

50

1000

1L

114

OOOZZ zzzzz ZZZZZ zzOLrlLri ZZZZZLn N -+ N

0 Lr1 0 0 Lll 00000 O Lrl O O O Ln Ln 0 0 111 Ln Ln Lf 0 Ln,--i -I .-1 rd 1-1 4-1 1-1 .-I 14-1

Z Z Z Z Z Z Z Z Z Z z z z z z z z z z z Z Z Z Z Z

00000 0 0 0 0 0 00000 O O O O O 00000Lr'1 Lrl Ill Ln h Ln h Ln h Ln Ln Ln h Ln h h h h Lrl h h h h h h

O Ln Ln Lr11--1 .-i 11 '-1 Ln Lr1 Ln O O Lrl Ill 0 Ln O Ln 00000 0 0 0 0 0

.-a '-d .-+ -1 -I N--I N N N N N N N N N N

aaaaa aaaaa aaaa aaaaa aaaaa

zzzzLn ZZZZZ zzzzz Lnzzzz zzzzz

O O O O O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0tf'1 Lrl Ln Ln h Ln O h h h h h i11 h h h h h h h h h h 1 / l

00000Ln O Lrl Li-1 0

00000M h Ln h h

OLrIOOL.n.-i 1--1 reel

00000Ln vl 0 LnN v-1 .-1

00000 O O O O O 000000001/10 00000 000a-)0N N C''1 N Cn

00000 0 0 0 0 0 00000 O O O O Oh h Ln Ln h h h u'1 Ln h h h h h h h h h h h

in 0 0 0 O O Ln Ln Ln Lr1 Lr1 Lr'1 Ln Ln Lnrl -I e--1 rM 1-4 .-i 1 If) Ln «l O Ln'-1 1-1 1--1 N r-1

Z Z Z Z Z Z Z Z Z Z z z z z z Z Z Z Z Z z z z z z

C/D C/D C/l Cll Vl C/D C/l CO cil VI Cr) CO Cn Cr: CIl C/l CO CO cl] CO CO C/D C1]N M Lrl h 00 O - N Lrl kO h 7O O 0-1 N M .t h CO 0\ OO 00 po 0r-4'--1 r-1 r-1 .-1 .--1 .-1 r-1 ..-1 .-1 N N N N N N N N M00000 0 0 0 0 0 00000 O O 0 O O 000006 1-) 1.7 1-.1

Appendix Ib -- continued

Sample

Sr

VW

YZn

Zr

Th

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

AJ001S

500

100

N20

L100

N

AJ002S

500

150

N30

L200

N

AJ003S

500

100

N30

I.

300

N

AJ005S

500

100

N30

L200

N

AJ007S

500

100

N30

L300

N

AJ008S

500

100

N30

L300

N

AJOlOS

500

100

N30

L200

N

AJ011S

500

100

N50

L200

N

AJ012S

500

100

N30

L200

N

AJ013S

500

100

N30

L300

N

AJ014S

500

100

N30

L300

N

AJ015S

500

100

N30

I.

200

N

AJ016S

500

100

N30

L200

N

AJ017S

500

100

N30

L200

N

AJ018S

500

100

N30

L200

N

AJ019S

500

100

N30

L200

N

AJO2OS

500

100

N30

L500

N

AJ021S

500

100

N30

L500

N

AJ022S

500

100

N30

L200

N

AJ023S

500

100

N50

L500

N

AJ024S

500

100

N50

L500

N

AJ027S

500

100

N30

L500

N

AJ028S

500

100

N30

I.

500

N

AJ029S

700

100

N30

I_,

300

N

AJO3OS

700

100

N30

L300

N

116116

u1 u1 un u'1 u"1 r, u'1 un un u1 u1 u1 u'1 C'7 u'1 u1 u'1 u'1 u1 M un u'1 ui u1 unW

d) U) U) U1 C/] U] U) C7 U1 U) U1 U] U] C!] U) UJ V) co U) Cn U] U] CID U] U]Ni C1 N. 00 0T O '-+ Ni Cl 1.0) N 01 Ln ,O r` CO CT O

01 M M M C1 C'l M on C1 .1- ,T ,t ,7 7 u1 ul in u1 u1 ul i.n u1 D .O O O O O O O O O O O O O O O 0 0 0 0 0 O O O O O6

1-4 a CV N N N N N N a 1--1 a r Z,rl GFA a.

.-A .- -- .-1 . .-+ .- . r. .i ..- r-, .- ,-1 tnW E

c 0 0 0 0 00000 O O c O o 0 0 0 0 0 0 0 0 0 00000o coocO o0000 00000 00000aa a 0000O c000O OOOrO oOOOO O r. 0,Oa -r ..

..+ o O o O O O Ó 0 0 0 O 0 O o O o O o O O o O O O OPO E Ln Ln Ln Ln in Ln un h r` r` un un un u1 un u1 un Ln un un ^ un u1 r, uî

a.._,

-. Z ZZ Z Z z ZZ z Z ZZ z z z z z Z Z Z Z Z Z Z Z

E¢ a.

zzZZZ zzzzz ZzzzZ ZzZZZ zzzZZ

.. ,4 CA aar- aa N ,4 -4 aaaaa azzzz6 á. óó ó ó

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u1 u1 un u'1 u"1 r, u'1 un un u1 u1 u1 u'1 C'7 u'1 u1 u'1 u'1 u1 M un u'1 ui u1 unW

d) U) U) U1 C/] U] U) C7 U1 U) U1 U] U] C!] U) UJ V) co U) Cn U] U] CID U] U]Ni C1 N. 00 0T O '-+ Ni Cl 1.0) N 01 Ln ,O r` CO CT O

01 M M M C1 C'l M on C1 .1- ,T ,t ,7 7 u1 ul in u1 u1 ul i.n u1 D .O O O O O O O O O O O O O O O 0 0 0 0 0 O O O O O6

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117

.. z z z z z z z z z z z z z z z z z z z z z z z z zO Een a

a

un un u1 un u1 un u1 un u1 0 u1 0 o u1 ul u1 ul ul u1 o u1 u1 u1 u1 unu E ,-, .-1 .--i .-i -1 .-t .-i .-1 -1 --i -1 -1 --1 -1 .-4 .-+ ,-.1 .-i ..-i -1 .--1 -1m aa"

. - - , Z Z Z Z Z z z z z z Z Z Z Z Z Z Z Z Z Z z z z z z-0Emaa

....

-. O O O O O 0 0 0 0 0 O O O O O O O O O O O O O O O,I1 N. O r\ ul r, N. r. r r` r` N. N. O M u'1 M r r- r.- O r. r` r` r, f\Fo. a ^4 M Na

..,

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0rl E M M M N M M N M M M M N CV un n r, r, r, un un r, N N N Nz aP.

g.a44444 44444 44444 4 a,-404 4 ra a4 4a

...

z z z z z z z z z z z z z z z z z z z z Z Z Z Z ZO F.

...

00000 00000 00000 00000 00000cu E u1 r. r. o o O o o r, o 0 0 o u1 r. N. r, r, r, r, r, r, o u, Lt)4 a . - -, -1 - -, -a .

CL

O O O O O O O O O O O O O O O O O O O O 0 0 0 0 0e 0 0 0 r, 0 r 0 0 0 0 O (il r, r, O r- 0 o u1 r, O O r` O r,C) a N ,-i .-, N M N 1-1 .--i

CL

O O O O O O O O O O O O O O O O O O O O O O O O Orrrunr, un r- r, r, r.ulr-ul0 OOO Cr- un u1r,r\r.U N u1 on N .u1 OOOO

COO

C)

O ul 1/1 ul u1 u1 u1 ul ul O O O O ul ul O ul u1 O ONi N N N ,-1 r- N N

z z z z z z z z z z z z z z z Z Z Z Z Z Z Z Z Z Z

(11 Cn vo vo vo vo Cn Cn vo co Cn C/) Cf1 Cn C/1 Cn CID vo Cn Cil pl C!1 Cn CI1 Cn DOr I N M.t ul qD r. C O 01 O N M.t ul CT N M u1 .D r` co Cr) OCL MMCIMM MMMM T ,t,1 ,f ,tulu1u1u1 ulinulul.OO O O O O 0 0 0 0 0 0 0 0 0 0 O 0 0 0 0 O O O O Oc<4

Appendix Ib -- continued

Sample

Sr

VW

YZn

Zr

Th

(PPm)

(PPm)

(PPm)

(PPn)

(PPm)

(PPm)

(PPm)

AJ031S

700

100

N30

L300

NAJ032S

700

100

N50

L200

NAJ033S

700

100

N50

L500

NAJ034S

1000

100

N30

L200

NAJ035S

700

100

N30

L300

N

AJ036S

1000

150

N30

L200

NAJ037S

700

100

N30

50

200

NAJ038S

700

100

N50

L200

NAJ039S

700

150

N50

L200

NAJO4OS

700

100

N50

L200

N

AJ041S

700

100

N50

L200

NAJ042S

700

100

N30

L300

NAJ043S

700

150

N30

70

200

NAJ044S

700

100

N30

L200

NAJ045S

700

150

N30

L200

N

AJ049S

700

150

N30

L200

NAJ051S

700

150

N30

L300

NAJ052S

700

100

N50

L300

NAJ053S

700

100

N30

L300

NAJ055S

1000

100

N20

L200

N

AJ056S

1000

100

N30

L200

NAJ057S

700

100

N50

L200

NAJ058S

700

100

N50

L200

NAJ059S

1000

100

N50

L300

NAJO6OS

700

100

N50

L300

N

119

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Lr) tn tn .-r N N Ill N itl -4 N. r`yE . .Pc) 1--1 0 0 0 O

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ázzzzz zzzzz zzzzz zzzzz zzzzz

áz z zz z z z z z z z z z z z z z z z z z z z z z

z z z z z z z z z z z z z i-1 -i z< á ó ó ó

...

0 0 0 c c O o 0 0 0 0 0 0 0 0 O c O O o o c o o OE c c O o c 0 0 0 0 0 0 0 0 0 o c c o o c o o c c oa -

r` ti-) Li.) rv i.n r r. O Lc) tn-4 '--

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M N M M C*) M M CV M N In c'') tn M N c*1 M N N N N N N N N

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\ .-r - .-i

t+'1 tr1 tn tn tr1 tn tn to in in N tn N r` N to If) is) to O r` r` ul to ur1QJ i.

N C!1 C/] L!) Cn C/) C/) rn C!1 C/] Cn G] C/] C/] C/) C/: C/] C/1 C/1 C/7 Cn C/] C/) Cnr I - M to .O N. DO Ch c N Lc) .O r` CO O1 O. N c*1 r CO O1a .o O O .O .D O n r- 00 00 CO 00 Co CO C)o CO CO00000 0 0 0 0 0 00000 O O O c 0 00000

f-- h P: h h r ?c! 6 6 < 6

r7¢ < 6 d 6 <4 < 6 6

120

Z Z Z Z Z Z Z Z Z Z ZZ z z z Z Z z Z Z Z Z Z Z Zgen .

CL.

.. u Ln Ln uÌ in O Ln Ln O L1-1 Ln L:1 ul L:1 Ln Ln Ln 0 0 0 u1 ul u,U E M M N ,-a --i --

C!)C-`

Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z.=C/0

0 0 0 0 0 0 0 0 0 0 O O C C Ln O O O O C O o o O O.fl E r` r` r` Q r` r` r` r` L!1 Ln Ln r` Mr- in ul M r` Ln N M O r` r`P-i a

O O O O O O C C O O O O Ln O u-) O o Ln O O 0 0 0 0 0ri E N N M N Ln N Ln Ln o M s-1 Ln -- Ln fn Ln .'-+ M r` r` r, C`'1 u, NZ -+

.-ID aZ a

Á

.,có Ea aa

e-sE

C..J a

}+ EU

a a a a a

z z z z z

p o 0 o OO r` r, C r,r -4

O C O 0 0r,Or,rr-

O O C O OOr`u,r`

a a a a a

z z z o z

p o O o Or, r, Ln r. r,

O O O O OOr`LnCDr,1--1

0 0 0 0 0r,LnOOO

a a a a a

Z Z z z z

O O O C OO r- r r- r,

0 0 0 0 LnLnoul Ln-+

O O C O OLnOr- ON

a a a a a

z z z z z

o O C o 0r- o r. O Ln,,- ,--

O 0 0 0 0Lnr1c*1Lnr`

0 0 0 0 0r,r`LnLnO

Ln

a a a a a

Z Z Z Z Z

0 0 0 0 0Ln r- r, r,

0 0 0 O Or`Cr`OO

C O 0 0 0OOr`r`OCr) Cr)

r O C O O O u1 O O O u, O O Li-) O a O C Ln 0 0 0 0 0 «1 OO E N N N N N .1 N N N -+ r 0 . 1 - I 0 . 1 N N Ln Ln Ln N CV

a

Z Z Z Z Z Z Z Z Z z z z z z z Z Z Z Z Z Z Z Z Z ZU

a

Cl) C/) Cr) Cr) Cr) U) CI) Cl) C!] CJ) C!) CID C/) CID C/) Cf) Cf) :n en Cr) Cr) Cn CID C!) Cr) Cl)ri ,--4 M d' u l S D r` 00 C A O N , t Ln V D r, 00 CT O'-+ N M ,t Ln r` 00 CNPL. Vo L.0 V0 V0 V0 .o Lo .o r r r., r- r- r, r, r, oo co 00 00 00 00 00 00 00E O O O O O o O O o O O O o p O o O O O c O O o 0 0

Appendix Ib -- continued

Sample

Sr

VW

YZn

Zr

Th

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

AJ061S

1000

150

N50

I.

200

NAJ063S

700

100

N50

L200

NAJ064S

700

150

N50

L200

NAJ065S

700

100

N50

Lr

200

NAJ066S

700

150

N50

50

200

N

AJ067S

700

100

N50

L300

NAJ068S

700

100

N50

L300

NAJ069S

500

70

N30

L200

NAJO7OS

500

100

N30

L150

NAJ072S

500

70

N50

L150

N

AJ074S

500

70

N50

50

200

NAJ075S

700

100

N50

L200

NAJ076S

500

100

N50

50

200

NAJ077S

1000

100

N50

L200

NAJ078S

500

100

N50

L150

N

AJ079S

1000

100

N50

L200

NAJO8OS

700

100

N50

L200

NAJ081S

500

100

N50

L200

NAJ082S

1000

150

N50

50

300

NAJ083S

1000

150

N30

50

100

N

AJ084S

1000

150

N30

L100

NAJ085S

700

200

N50

L300

NAJ087S

700

100

N50

L300

NAJ088S

700

100

N30

L300

NAJ089S

700

100

N50

L300

N

122

zzzzz zzzzz zzZZZ zz..E O O O COCO OW e-IP .. .. .. ., , .. .. .. ..zzz zzzz z

ti ,r --iC

Pgl

P.

Ln Ln Ln Ln Lfl Ln u1 u1

.--i ..4 1-1 1-1 e--i

O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0c*J E 00000 00000 O O O O C O O O O O O O O O OGU CL OLnO O O Or\O O O 0000o O OLnulLfl u-) un un un u1

CL

O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 OE Lfi Ln Ln Lfi Ln Ln Ln u-) Ln Ln Ln Ln Ln Ln Ln ui u1 Ln Lf1 Ln ui Ln Ln Ln LnCLCL

6 aa

E

o) ei6 a

../

Z z z z z z z z ZZ z z z z z

zzzzz zzzzz zzzzz

zzzzz zzaaz zzzzz

.. o 0 0 0 0 0 0 0 0 0 O o 0 0 0E 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

N. U1 I, f` f\ C\ Ln r, ti t\ O 0w r, Co Lna, +

O 0 0 o O 0 0 0.. ... .. .. . .. ...zzz zzzzz

z z .. ,. .. ,. .. .. .. ..O 00 00000O O o O O O O ON N N N N N N

.,.zzz zzzzzLn Ln

tf1 ui Lfi Ln ,

ò 0 ó0o

z z z

0 0 0 0 00 0 0 0 0un u1 f, r, r,

0 0 0 0 0o c o 0 0t\ f` n t\ Ln

t\ .-+ f, r\ n n n t\ r` t\ n t\ N Lf) N N N N N M{ .-I .. . . . . . . . .H\ O 0 0 0 O O O O O O O O O O O O O O

O

O 01 M cn N N N N N N Ln N N N M N N N N N Ln N Ln Ln u1cd -U ,-I .-i ,-4 .-+

.--i N N ul N N,--i N N N N N N N Ln N N n n r\ Ln Ln un Ln N-O-'

O 0 0 oc 00 C

Ln O Lf1 Ln ul ul un u1 Ln ul Ut I- U1 Ln Ln Ln Ln M N N .-i M N N M

H

N En C/] a] u] ul V] U C/o C!7 En vo CI] vo C/] Cn C/o vo U] C/5 uIJ Cu] Cfi Cll Cn fnr-I O r+ N M7 ,O r` CO C r O N Mt ul ) . 0 n r-+ N M co O, O 01 ,i-CL a, C0 gr) c h 01 CN CN Cr, T o 0 0 0 0 0 O 0 - - -1 - u-) Ln u1E O O O C O O C_ O O, ,--I ,-+ r, .-a .-.i ,-i ,-- .-+ , .--. '-, .-

CO ; 6 6 2 r C , '1,262 : 2 ' -< , . 2 : 2 ', 2 ' <4.6

.. Z Z Z Z Z Z Z Z Z Z Z Z Z Z ZO E

cn a

123

Z Z .. ,-, ,. ,-, ,. .-N000 O O O O O... .. ../ .. `/ `/ .,.zzz zzzzz

U1 O U1 U1 U1 U1 U1 U1 in in U1 U1 U1 Ul U1 Ul v1 O O O O C O O Ori ri

cn

P4

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a

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Z Z Z Z Z

00000r. r.

o000oN U1

z z z Z Z

O O O O Oh U) Ln r` N.

OoOOOr N V'1 r` N

Z Z z z z

00000N. r` r` r` U1

o0000Cr) M U1 U1 M

/\ ,1 r\000000.-e ... ..zzz

0 0 0 0 0u'1 ul U1 M M

00 LnoinM

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0000Ln

/ a a I-- F+ I--; ra I--1 ha aZ á

zzzzz zzzzz zzzzz zzzzz ZZZZZE

..,

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COCCOO O U1 N . r`.- ,--i .-a

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0 0 0 0 0N. r` N. r. N.

0 0 0 0 0r` r, r` O r`I-I

O O O O Or r\ O Or--.N N

00000N. N. N. N.

0 0 0 0 0in r- U1 O r1--I -4

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0 0 0 0 0N. N. N- i.n

0 0 0 0 0N-0 O r` r,1--1 r-i

0 0 o c Or\ r` U1 M U1

00000Ln Ln Ln

Q0000r` O O r, Or-1 -I r-1

00000M tf1 N U1 r`

..

. 0 0 0 0 0 O Ln O O t.l1 u'1 0 0 0 0 0 0 Oinin v1 O U1 Ln OO E N M M N N cr1 N-+ ,--I N N N N N NU

Z Z Z Z Z Z Z Z Z Z z Z z,7. zEb ó o o ó ó ó ó.. zzz zzzzz

N Cln Ul Cn CID Cn Cn Cn G] CID C/) Cn Cn V] Cn Cn Cn Cf) C!] Cf) Cf) cn up Cn CI: Cn.-I O--, N M1' .O r. OJ 0 O --I N re) .1' u-1 O n.-; N M OC) O, O M-.7CL Ol O1 O) O a, Cr, O\ O", CT O O O O O O O O 7 7 T -..1' .....t u1 in tnE 00000 O O O O r1 ,-a r-+ ,-.1 r-r .--i r-a r1 r-+ r-{ .-i r-, r-r ,--i 1--1.-1

cñ < 6 < < d < < < < < 6 < 6 < < < d < ¢ < < <

Appendix Ib -- continued

Sample

Sr

VW

YZn

Zr

Th

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

AJO9OS

700

100

N30

L200

NAJ091S

1000

100

N50

L300

NAJ092S

700

150

N30

50

300

NAJ093S

700

100

N30

L200

NAJ094S

700

150

N30

L300

N

AJ096S

1000

150

N30

L300

NAJ097S

500

100

N30

L300

NAJ098S

500

150

N30

L200

NAJ099S

700

150

N30

L300

NAJ100S

700

150

N30

L300

N

AJ101S

700

150

N30

L300

NAJ102S

700

150

N30

L200

NAJ103S

1000

100

N30

L300

NAJ104S

1000

150

N30

L200

NAJ105S

700

150

N30

L200

N

AJ106S

700

150

N50

L300

NAJ107S

700

150

N30

L300

NAJ141S

300

70

N(50)

15

L(200)

150

NAJ142S

300

70

N(50)

15

N(200)

150

NAJ143S

300

50

N(50)

15

L(200)

150

N

AJ148S

300

70

N(50)

15

N(200)

150

NAJ149S

300

70

N(50)

30

L(200)

200

NAJ150S

300

50

N(50)

20

L(200)

100

NAJ153S

300

50

N(50)

20

L(200)

150

NAJ154S

300

70

N(50)

20

N(200)

300

N

Appendix Ib -- continued

Sample

Fe

Mg

Ca

Ti

Mn

Ag

As

Au

BBa

Be

Bi

(%)

(%)

(%)

(%)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

AJ158S

20.7

10.2

500

N(0.5)

N(200)

N(10)

50

500

1N(10)

Appendix Ib -- continued

Sample

Cd

Co

Cr

Cu

La

Mo

Nb

Ni

Pb

Sb

Sc

Sn

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

AJ158S

N(20)

10

20

70

50

NL

10

20

N(100)

7N(10)

Appendix Ib -- continued

Sample

Sr

VW

YZn

Zr

Th

(PPm)

(PPm)

(PPm)

(PPm)

(pptn)

(PPm)

(PPm)

AJ158S

300

50

N(50)

20

N(200)

150

N

L = Detected at levels below the detection limit

N = Not detected at lower detection limit

Lower detection limits

Element

Lower

Detection

Limit

(unless otherwise indicated):

Element

Lower

Element

Detection

Limit

Lower

Detection

Li

Element

Lower

Detection

Limit

Fe

0.05 %

Be

0.5 ppm

Pb

Th

100 ppm

Mg

0.02 Z

Bi

2 ppm

Sb

Ca

0.05 Z

Cd

5 ppm

Sc

5 ppm

Ti

0.002 Z

Co

5 ppm

Sn

5 ppm

Mn

10 ppm

Cr

10 ppm

Sr

100 ppm

Ag

0.1 ppm

Cu

1 ppm

V10 ppm

As

50 ppm

1.a

20 ppm

W100 ppm

Au

2 ppm

Mo

5 ppm

Y10 ppm

B10 ppm

Nb

20 ppm

Zn

50 ppm

Ba

20 ppm

Ni

5 ppm

Zr

10 ppm

APPENDIX Ic

ANALYTICAL RESUTLS (USING SEMI -QUANTITATIVE EMISSION SPECTROGRAPHY)

FOR THE C -3 FRACTION OF HEAVY MINERAL CONCENTRATES,

BATAMOTE MOUNTAINS, ARIZONA

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CG Gr-I

r!Cd

4-) ro

a)x

GO

.ood ß.

P.-..

G Eaa.

r1E-a \

(d i.U \

ZZZZZ

COCCOO O O O Or, r u l i.n tr1

i. ,-,N N N N NvC7 C7 C) C7 ü

O O O O N.I--I ri '-. r-I

N N N --i N

M M M M M

ZZZZZ

OOOOOO O O O OLr1 Cn rr1 r.

i.N N N N NuC.) C7 0 C7 C7

O O O O O.-i r-1 .-i .-- --

N N N N N

N M 01 M M

ZZZZZ

COCCOO O O O OCr1 r r, Cr1 r-

,-. r. r. ,-.N N N CV CV

C7 C7 C7 C_) C7

O O O O Or-I --i -- r-I .--

N N N N N

N 01 M M M

ZZZZZ

COCCOO O O O Oir1 un N. Lr1 M

,-, r-. i. r. ,-,N N N N N

).C7 C7 C7 C7 C7

O O O O O.-1 -1 r-1 ,-- --i

N N N N N

M M M M 01

ZZZZZ

OOOOOO O O O Ou r1 N. u i

i. i. .. .-. i.N N N CV N

C7 C7 CL CD C7

O O O O Or-1 ri r-1 .-i rI

N N N N

M M M N N[-

CJ `H

ri M M M M M M M M M M M M M M M M M M M M M M M M M^Cy a) CJ CJ CJ C.) U ü CJ 0 0 0J C7 CJ CJ U C) J CJ U C) U CJ CJ C) U C.7G N M.7 url ,O h- CO Oh O --r N 01 ,t r, CX) ON CO N 01 ,T r,a) p. N N N N N N N N M M M M M c+1 M MPL E O O O O O O O O O O O O O O O O O O O O O O O O OCL

6 1.-eZ

Appendix Ic-- continued

Sample

Cd

(ppm)

Co

(ppm)

Cr

(ppm)

Cu

(PPm)

La

(PPm)

Mo

(131m)

Nb

(PPm)

Ni

(PPm)

Pb

(PPm)

Sb

(PPm)

Sc

(PPm)

Sn

(PPm)

AJ011C3

NL

200

200

500

N100

L70

100

70

100

AJ012C3

NL

200

150

500

N100

L100

L50

150

AJ013C3

NL

200

150

500

N100

L70

L50

50

AJ014C3

NL

200

150

500

N100

L70

N30

50

AJ015C3

NL

100

100

500

N100

50

20

N20

30

AJ016C3

NL

200

150

500

N100

30

70

N30

50

AJ017C3

NL

150

150

500

N100

L50

N30

50

AJ018C3

NL

100

150

500

N100

L50

N30

50

AJ019C3

NL

150

150

500

N100

L200

N30

50

AJ020C3

NL

150

200

500

N100

L300

N30

70

AJ021C3

NL

200

150

500

N100

L100

N30

70

AJ022C3

NL

200

150

500

N100

L70

N30

70

AJ023C3

NL

150

200

500

N100

50

70

N30

70

AJ024C3

NL

100

150

500

N100

20

50

N30

50

AJ027C3

NL

200

150

500

N100

L50

N50

70

AJ028C3

NL

150

150

500

N100

L70

N30

50

AJ029C3

NL

150

150

500

N100

50

2000

N20

70

AJ030C3

NL

200

150

500

N100

L70

N30

100

AJ031C3

NL

150

200

500

N100

50

50

N20

50

AJ032C3

NL

150

150

500

N100

20

70

N20

50

AJ033C3

NL

200

150

500

N100

L50

N30

50

AJ034C3

NL

200

200

500

N100

L70

N30

70

AJ035C3

NL

200

150

500

N100

20

50

N30

70

AJ036C3

NL

200

150

500

N100

20

30

N30

30

AJ037C3

NL

200

200

500

N100

20

70

N30

50

w o

Appendix Ic -- continued

Sample

Sr

(PPm)

V

(PPm)

W

(PPm)

Y

(PPm)

Zn

Zr

(PPm)

(PPm)

Th

(PPm)

AJ011C3

300

200

N700

N G(2000)

NAJ012C3

300

200

N700

N G(2000)

L

AJ013C3

300

200

N500

N G(2000)

N

AJ014C3

300

200

N500

N.G(2000)

L

AJ015C3

300

200

N300

N G(2000)

N

AJ016C3

300

200

N500

N G(2000)

NAJ017C3

300

200

N500

N G(2000)

L

AJ018C3

700

200

N300

N G(2000)

N

AJOI9C3

700

200

N500

N G(2000)

N

AJ020C3

300

200

N500

N 0(2000)

L

AJ021C3

300

200

N500

N G(2000)

L

AJ022C3

500

200

N500

N G(2000)

L

AJ023C3

500

300

N500

N G(2000)

L

AJ024C3

500

200

N500

N G(2000)

N

AJ027C3

300

200

N500

N G(2000)

L

AJ028C3

300

200

N500

N 0(2000)

L

AJ029C3

300

200

N500

N 0(2000)

N

AJ030C3

300

200

N500

N 0(2000)

L

AJ031C3

300

200

N500

N G(2000)

N

AJ032C3

1000

200

N500

N G(2000)

N

AJ033C3

700

200

N500

N 0(2000)

N

AJ034C3

700

200

N500

N G(2000)

N

AJ035C3

700

200

N500

N 0(2000)

N

AJ036C3

500

200

N500

N 0(2000)

NAJ037C3

500

200

N500

N G(2000)

Nw

t!

-

132

r4a1

vaa

cuPa

PD

EC.a,

EwCL

EGLCL

a.GL

zzzzz

0 0 0 O 0oCOO oO O O u1 ON N r-e

O o 0 O CO h. O(, n-a ,

zzzzz

z z z z z

0 0 0 0 oOOOOOO(', I, 1/1 u1

O

O O O O Ou1 C n u1 ul

zzzzz

z z z z z

O O O 0 0CoCOOr, r` r. M u1

O O O 0 0111 t, u'f ul

zzzzz

z z z z z

0 0 0 0 0OOCCOO n O ul O

u1 .-a u1

O C C O OO O N h, ir1

zzzzz

z z z z z

o C O a oooOCc,r` u1 u1

--

0 0 C o 0N u"1 01 h, n

Z Z Z Z Z Z z z z z z z z z z Z Z Z Z Z z Z z z z< P1.

Z Z Z Z Z z z z z z z z z z z Z Z Z Z Z Z z z z Zz17

6 a....

zzzzz zzzzz zzzzz zzzzz zzzzzWE<4 a

...

O O o 0 0 0 O o O C O O O O C C O O o CE O O O O O o o O o o O O C o 0 C O C o 0

x a. 1, ,-, u1 u1 h, u1 u1 01 r, c1 M M u1 u1 u1 u1 111 u1 u1 u1

o 0 0 0 00 0 0 0 0u1 u1 u1 u1 Cl

.-. .. .-. .. ,-, .-. .. .-, ., .. .. .-. . .. ,-. ,-. ., .. ., .. .. ,. .. .-. ,-. ..H\ N N N N N N N N cV N N N N N N N N N N N N N N N N...i\..,u v \-,

C7 C7 C7 U U CD C" C.7 C7 CD C7 U C7 CJ C7 U U C7 C7 U CD U C.7 C.: C7

O O O O O O O O O O O O O O O O O O O C C u1 O O OcÒ r-t

C.) \

M Ci N N C1 N r*1 u1 C1 u1 N N u1 na N N N N N C1 N N N N u1On ..

C1 M M N Cl N N N 01 N M c*1 N N 01 01 M N C1 M 01 M N N N(1)

w \

c'1 cl M M M M M M M 01 r1 M M 01 M 01 M 01 c*1 M 01 01 C1 C1 01(I) U U U U U U U U U C.) C) U U U U U U U U U U U U U U

,--i o0 01 0--+ N 01 -4' ul 01 ,--1 N 01 u1 qa r, 00 01 O,--+ c+1 .t ul ,0 h, 00CL M 01 .t .t .t .T .t .t .t u1 In u1 In In u1 ul u1 AO AO AO AD AD AD AD AUa o o C 0 0 C C O O O O O 0 0 0 0 0 0 0 0 C O O 0 0c ¢

Appendix Ic -- continued

Sample

Cd

(PPm)

Co

(PPm)

Cr

(PPm)

Cu

(PPm)

La

(PPm)

Mo

(PPm)

Nb

(PPm)

Ni

(PPm)

Pb

(PPm)

Sb

(PPm)

Sc

(PPm)

Sn

(PPm)

AJ038C3

NL

200

300

500

N100

50

50

N50

50

AJ039C3

NL

200

150

500

L100

30

100

N30

50

AJ040C3

NL

200

50

500

N100

L70

N30

50

AJ041C3

NL

200

100

500

N100

L50

N30

30

AJ042C3

NL

200

100

500

N100

20

100

N50

30

AJ043C3

NL

200

100

500

N100

50

50

N20

30

AJ044C3

NL

500

70

500

N100

20

50

N30

20

AJ045C3

NL

100

150

500

N100

20

50

N20

30

AJ049C3

NI.

200

150

500

N100

20

50

N30

30

AJ051C3

NL

100

150

500

N100

20

50

N20

30

AJ052C3

NL

100

150

500

N100

10

100

N30

30

AJ053C3

NL

150

150

500

N100

50

30

N50

30

AJ055C3

NL

150

100

500

L100

50

50

N30

30

AJ056C3

NL

150

50

500

N100

50

50

N20

30

AJ057C3

NL

150

150

500

70

100

10

300

N50

50

AJ058C3

NL

200

150

500

N100

50

50

N50

150

AJ059C3

NL

150

150

500

N100

20

30

N30

70

AJ060C3

NL

150

150

500

N100

10

30

N30

20

AJ061C3

NL

200

150

500

N100

10

50

N30

30

AJ063C3

NL

200

200

500

N100

10

1000

N30

20

AJ064C3

NL

200

150

500

N100

10

100

N30

30

AJ065C3

NL

200

150

700

N100

20

50

N50

50

AJ066C3

NL

200

100

500

N100

L30

N30

50

AJ067C3

NL

200

150

500

N100

L200

N30

70

AJ068C3

NL

150

150

500

N150

L100

N30

50

134

. z azzz azzzz zzzzz zzzzz z zOa aEF 0,

,. .. .. .-. , . . .. . . .. ,, .. .-. ,1 .-. . -. .. .1. . ..1 .. .-. .-. .. ..ooOOC ooOCO 00000 COCCO 00000N a o O C o 0 o O o 0 o O O o C 0 coco 0 0 0 0 0 0C3 O C 0 0 0 co 0 0 0 0 0 0 0 0 0 0 0 0 0 00000..i N N N N N N N N N N N N N N Cl N N N N N N N N N Nv.. .. ..i .v`. .,,.

C7 V C7 C7 C7 C7 C7 C7 Cä C7 C C7 C J C,7 C7 C.7 C.:' C C7 C7 C-7 C7 O C7

EZ Z Z Z Z z z z z z Z z z z z Z Z Z Z Z z Z Z Z Z

N fS...

G.yOU

I

I

UH

r177GUp..

6

i.CL

E

CL

Ep.

..

+ EC/) P.

ß.

vr-i

O.E

co

O C O O OO O O O Ou1 u1 u1 u1 411

Z Z Z Z Z

c c c c cN Cl N N N

00000O O C O Cul O r, O

M M M M MU U CJ U U00 0h O,--1 NM M -Zr -Zr 7O o C C C

O O O O CO O O O Ou1 M M M M

z z z z z

c c c c cN N N N N

0 0 0 0 0C C O O OO Or, f\ n

M M M M MU U C.) CD UM -Zr u1 ON ,--i-Zr -Zr -Zr -Zr u1C O O O O6 6

O O O O CO C C O OM u1 01 M u1

Z z z z z

c c c c cN N N N N

00000O O O C OOr, n n u1

M M M M MCD U U U UN M ul `C nu1 u1 un u1 u1O O C O O6 6 d 6

O C O O OO O O O C

. M u1 ul u1 u1

Z Z Z Z Z

c c c c cN N N N N

O O O C OO C C O O1`, r- Cr, r,

M M M M MU U CJ U Uco Cr) O,--f Mu1 u1 JD JD gDO C O O O6 6 d

O O O O CO O O O Cu1 u1 u1 u1 ul

z z z z z

c CC c c cN N N N N

0 0000O C O O Ot\ un un (, N

M M M M MU U U U U-Zr Li-) ,D r, COJD D s.D gD ,DO C O O O6 6

Appendix Ic -- continued

Sample

Fe

Mg

Ca

Ti

Mn

Ag

As

Au

BBa

Be

Bi

(%)

(%)

(%)

(%)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

AJ069C3

31

15

G(2)

1000

NN

N20

150

NN

AJ070C3

21

10

2200

NN

N50

500

NN

AJ072C3

31

10

C(2)

1000

NN

N70

150

NN

AJ074C3

33

10

G(2)

500

NN

N20

50

LN

AJ075C3

51.5

15

G(2)

300

N(0.5)

N(200)

N(10)

150

150

1N(10)

AJ076C3

21

10

G(2)

500

N700

N50

200

LN

AJ077C3

20.7

10

G(2)

300

NN

N30

100

LN

AJ078C3

20.7

10

G(2)

500

30

NN

50

1000

LN

AJ079C3

21

10

G(2)

300

2N

N50

200

LN

AJ080C3

20.7

10

G(2)

300

NN

N50

1000

LN

AJ081C3

31

10

G(2)

700

NN

N20

1000

LN

AJ082C3

10.7

15

1500

NN

N20

150

LN

AJ083C3

10

710

11000

NN

N20

700

LN

AJ085C3

52

10

2500

NN

N20

700

LN

AJ087C3

30.7

10

G(2)

300

NN

N20

700

LN

AJ089C3

30.7

10

G(2)

500

NN

N30

5000

LN

AJ090C3

20.7

10

G(2)

500

NN

N70

1500

LN

AJ091C3

21.5

10

G(2)

700

NN

N50

500

LN

AJ093C3

21.5

10

G(2)

700

NN

N50

700

LN

AJ094C3

32

10

G(2)

500

NN

N70

300

LN

AJ096C3

32

10

G(2)

500

NN

N50

300

LN

AJ098C3

31.5

7G(2)

500

NN

N50

500

LN

AJ100C3

32

10

G(2)

500

0.5

NN

100

1500

NN

AJ101C3

32

10

G(2)

500

NN

N50

500

LN

AJ102C3

35

10

G(2)

500

NN

N100

200

LN

Appendix Ic-- continued

Sample

Cd

(PPm)

Co

(PPm)

Cr

(PPm)

Cu

(PPm)

La

(PPm)

Mo

(PPm)

Nb

(PPm)

Ni

(PPm)

Pb

(PPm)

Sb

(PPm)

Sc

(PPm)

Sn

(PPm)

AJ069C3

NL

70

70

700

L100

10

70

N30

100

AJ070C3

NL

70

150

200

N200

L30

N20

NAJ072C3

NL

100

100

500

10

100

L70

N30

1000

AJ074C3

NL

200

30

506

N100

L50

N50

500

AJ075C3 N(100)

N(20)

200

150

700

N(20)

200

10

20

N(50)

50

70

AJ076C3

NL

50

50

500

N100

L150

N20

50

AJ077C3

NL

150

50

500

N150

L50

N20

30

AJ078C3

NL

150

30

700

L100

L50

N20

50

AJ079C3

NL

150

100

700

N100

L50

N20

50

AJ080C3

NL

100

100

700

N100

L50

N20

50

AJ081C3

NL

200

100

1000

N100

L50

N20

100

AJ082C3

NL

20

100

1000

N100

L20

NN

20

AJ083C3

NL

500

100

200

N100

100

10

N50

NAJ085C3

NL

150

150

500

N100

L30

N30

20

AJ087C3

NL

50

70

500

N100

L30

N20

50

AJ089C3

NL

100

150

500

N100

L300

N30

50

AJ090C3

NL

100

150

500

N100

L200

N20

30

AJ091C3

NL

200

300

500

100

100

L2000

N20

50

AJ093C3

NL

300

100

500

N100

L100

N20

50

AJ094C3

NL

200

70

500

N100

L30

N30

50

AJ096C3

NL

300

70

700

L100

L200

N20

50

AJ098C3

NL

150

100

500

N100

L30

N20

30

AJ100C3

NL

300

100

500

N100

L50

N30

50

AJ101C3

NL

300

150

500

L200

L30

N20

50

AJ102C3

NL

500

30

500

L150

L50

N30

50

w ch

137

zzzOr. zzzaz zzzzz zzzzo oazza. o 0 o 0E-I a, ' N O N ina ,n

z¡-s i. i. i. i. .. i. r. ..$.4 C o o O O O C O 0 0 C O C O O C O O C C o 0 0 0 0N O. O O O O O O O O O O 0 o C C 0 0 0 0 0 0 O C O O O

G. O C O o 0 O O C O 0 C o 0 0 0 O C O 0 0 0 0 0 0 0N N N N N N N N N N N N N N N N N N N N N N N N NC7 U C.7 C7 G 0 0 0.7 C7 U C7 C7 C7 C7 C7 C.7 U :7 C.7 U C: C7 C7 U C.7

z z ZZ Z Z z z z z z z z z z ZZ Z Z Z Z ZE ON C, CN

z0 0 0 0 0 O 0 o C o O o C o 0 0 0 0 0 o O O o 0 0E oOOCO OoOOO ooOOO 000OO OooOO

CL O M O M to 01 M M u1 to u1 ul . M u1 u1 in un u'1 u1 u") M ur1 u'1 u1C. -+

i. zzzzr, Z Z Z Z z Z Z Z Z Z Z Z Z Z Z Z Z Z Z ZE OCL Ca u1... .zr. o C o o C O C C O O o C o C o C o o O C C C C O OD> E CCOCC ululCO C OoOu10 OOOOC o000ON-- N N Cn N N N N-+ N N N N N N cg N N N N

C.`.

O O O O O O C O O C 0 0 0 0 0 O O O O O C C O 0 0>+ E O o O O c o 0 o O O o C O 0 0 O 0 o O o O C O O OCO p., M r, M N r` M N i11 M u'1 ul N u1 ur1 in r, u1 r, r, Grl un N ul u un

CL

M M M M M M M M M M M M M M M M M M M M M M M M Ma) U C.J U C) CJ C) U U CJ CJ C7 CJ U C) CJ C) CJ U C) U CJ C) U U C)

O1 O cg . t ul u ) r - c l ) C N M u1 n Q1 C M,.7 O CO CD .-i Nt3 O r\ r, r, r- r, n t\ r, co co 00 co 00 co co Oh Oh ch ch CT Ch O O C00000 00000 00000 00000 00.-+-+cif r, ro

<4 <4 <4 -4 <4 <4 -4 <4 <4 <4 <4

Appendix Ic -- continued

Sample

Fe

Mg

Ca

Ti

Mn

Ag

As

Au

BBa

Be

Bi

(X)

(X)

(%)

(X)

(PPm)

(PPn)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

AJ103C3

33

10

G(2)

700

NN

N70

200

LN

AJ105C3

35

15

G(2)

700

NN

N50

700

LN

AJ107C3

35

15

G(2)

700

NN

N50

5000

LN

AJ117C3

52

30

G(2)

5000

N(1)

700

N(20)

200

700

520

AJ127C3

10

220

G(2)

5000

N(1)

700

N(20)

200

2000

5L(20)

AJ128C3

21

15

G(2)

2000

N(1)

L(500)

N(20)

200

2000

5N(20)

AJ132C3

31

15

G(2)

2000

N(1)

1000

N(20)

200

2000

5N(20)

Appendix Ic -- continued

Sam

ple

Cd

Co

Cr

Cu

La

Mo

Nb

Ni

PbSb

ScSn

(PPm

)(P

Pm)

(PPm

)(P

Pm)

(PPn

)(P

Pm)

(PPm

)(P

Pm)

(PPm

)(P

Pm)

(PPm

)(P

Pm)

AJ103C3

NL

500

50500

N150

L30

N30

50

AJ105C3

NL

500

200

500

200

100

20

700

N30

50AJ107C3

NI.

500

5050

0L

150

20

70

N30

100

AJ117C3

N(5

0)N

30

500

500

N10

0L

200

300

N50

AJ127C3

N(5

0)N

150

500

500

N10

0L

200

200

N50

AJ128C3

N(5

0)N

50300

500

N10

0L

150

200

N50

AJ132C3

N(5

0)N

70

200

500

N10

0L

150

200

N200

Appendix Ic -- continued

Sample

Sr

VW

YZn

Zr

Th

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

(PPm)

AJ103C3

300

200

N500

N G(2000)

L

AJ105C3

700

200

N500

500 G(2000)

N

AJ107C3

700

200

N500

N G(2000)

L

AJ117C3

1500

200

N(100)

500

N(500) G(2000)

N

AJ127C3

2000

200

N(100)

500

N(500) G(2000)

N

AJ128C3

2000

200

N(100)

700

N(500) G(2000)

N

AJ132C3

2000

100

N(100)

500

N(500) G(2000)

N

L = Detected at levels below the detection limit

N = Not detected at lower detection limit

G = Greater than value shown

Lower detection limits (unless otherwise indicated):

Element

Lower

Detection

Limit

Element

Lower

Detection

Limit

Element

Lower

Detection

Limit

Element

Lower

Detection

Limit

Fe

0.1 %

Be

1 ppm

Pb

5 ppm

Th

200 ppm

Mg

0.05 %

Bi

5 ppm

Sb

20 ppm

Ca

0.1 %

Cd

10 ppm

Sc

10 ppm

Ti

0.005 %

Co

10 ppm

Sn

10 ppm

Mn

20 ppm

Cr

10 ppm

Sr

200 ppm

Ag

0.2 ppm

Cu

2 ppm

V20 ppm

As

100 ppm

La

50 ppm

W200 ppm

Au

5 ppm

Mo

10 ppm

Y20 ppm

B Ba

20 ppm

50 ppm

Nb

Ni

50 ppm

10 ppm

ZnZr

100 ppm

20 ppm

}-, ó

APPENDIX Id

ANALYTICAL RESULTS (USING SEMI -QUANTITATIVE EMISSION SPECTROGRAPHY)

FOR OXIDE COATINGS ALONG JOINTS AND FRACTURES, BATAMOTE MOUNTAINS, ARIZONA

141

Appendix Id-- Analytical Results (Using Semi -Ouantitative Emission Spectroscopy) for Oxide Coatings

Along Joints and Fractures, Batamote Mountains, Arizona

Sample

Fe

(1)

Mg

(%)

Ca

U.)

Ti

Mn

(70)

(PPm)

Ag

(pPm)

As

(PPm)

Au

(PPm)

B

(PPm)

Ba

(PPm)

Be

(PPm)

Bi

(PPm)

AJ136R

50

15

0.2 G(10,000)

2500

N(20)

500

5000

20

100

AJ152R

50

110

0.2 G(10,000)

1700

N(20)

100

1000

15

150

AJ155R

50

75

0.7 G(10,000)

1L(500)

N(20)

500

2000

15

100

AJ162R

75

20.1

5000

7N(200)

N(10)

100

700

25

AJ163R

10

23

0.2

G(5000)

7N(200)

N(10)

100

700

72

AJ164R

15

23

0.15

G(5000)

1N(200)

N(10)

100

2000

72

AJ165R

20

1.5

30.15

G(5000)

30

N(200)

N(10)

100

1500

77

AJ166R

15

1.5

20.2

G(5000)

2N(200)

N(10)

100

2000

75

AJ167R

51

0.5

0.02

1500

5N(200)

N(10)

100

150

23

Appendix Id-- continued

Sample

Cd

(PPm)

Co

(PPm)

Cr

(PPm)

Cu

(PPm)

La

(PPm)

Mo

(PPm)

Nb

(PPm)

Ni

(PPm)

Pb

(PPm)

Sb

(PPm)

Sc

(PPm)

Sn

(PPm)

AJ136R

N(50)

700

200

2000

200

50

L(50)

150

1500

1000

20

500

AJ152R

N(50)

500

50

2000

500

100

L(50)

100

1500

300

50

20

AJ155R

N(50)

500

150

3000

100

50

100

300

1000

200

20

100

AJ162R

10

200

150

500

50

70

20

500

700

20

5N(10)

AJ163R

10

70

100

200

100

50

20

70

700

20

10

N(10)

AJ164R

20

200

100

200

100

50

20

100

200

N(10)

20

N(10)

AJ165R

20

500

50

500

200

70

20

100

1000

30

20

N(10)

AJ166R

20

500

50

100

200

70

20

100

200

10

30

N(10)

AJ167R

N(10)

50

100

100

50

N(5)

L(20)

50

150

N(l0)

L(5)

N(10)

Appendix Id -- continued

Sample

Sr

(PPm)

V

(PPm)

W

(PPm)

Y

(PPm)

Zn

(PPm)

Zr

(PPm)

Th

(PPm)

AJ136R

200

300

N(100)

200

1500

500

N(200)

AJ152R

200

200

N(100)

700

500

500

N(200)

AJ155R

200

500

N(100)

50

2000

700

N(200)

AJ162R

200

500

N(50)

10

500

100

N(100)

AJ163R

200

200

N(50)

50

500

300

N(100)

AJ164R

200

200

N(50)

150

500

300

N(100)

AJ165R

200

200

N(50)

150

500

200

N(100)

AJ166R

200

150

N(50)

200

500

300

N(100)

AJ167R

N(100)

30

N(50)

10

L(200)

50

N(100)

L = Detected at levels below the detection limit

N = Not detected at lower detection limit

G = Greater than value shown

APPENDIX II

ANALYTICAL TECHNIQUES

145

146

Appendix II-- Analytical Techniques

Nitric Acid Extraction (Modified after Ward and others, 1969)

1. Weigh 0.50 grams of sample into 20 ml disposable test tube contain-ing boiling chip.

2. Add 2.5 ml of concentrated nitric acid.

3. Heat for 30 minutes to drive off nitrous oxides.

4. Dilute to 10 ml with distilled water and bring to a boil.

5. Cool and centrifuge.

6. Analyze extract using atomic absorption spectrophotometry (expansion20).

First Sequential Extraction (T. T. Chao, 1983, personal communication;modified after Olade and Fletcher, 1974; modified after Filipek andOwen, 1978)

Oxide Fraction

1. Weigh 0.50 grams of sample into 50 ml centrifuge tube.

2. Add 25 ml of.3% oxalic acid, cap and shake.

3. Heat in preheated block at 100 °C for 15 minutes.

4. Centrifuge and decant liquid into 50 ml beaker.

5. Wash and dry remnant sample in test tube.

6. Evaporate liquid in beaker to dryness.

7. Place beaker in furnace at 500 °C for 4 hours to burn off oxalic acid.

8. Dissolve residue in 25 ml of 4 N nitric acid (2.4 N hydrochloricacid is also adequate) and stir.

9. Analyze extract using atomic absorption spectrophotometry (expansion= 50).

Sulfide and Organic Fraction

10. Add 0.50 grams of potassium perchlorate to remaining sample.

11. Add 5 ml of concentrated hydrochloric acid.

147

Appendix Il -- continued

12. Let stand for 30 minutes.

13. Dilute to 25 ml with distilled water and shake.

14. Centrifuge.

15. Analyze extract using atomic absorption spectrophotometry (expan-sion = 50).

16. Decant off extract and wash remaining sample.

Crystalline Fraction

17. Wash sample into 50 ml teflon beaker and evaporate to dryness.

18. Add 10 ml of concentrated hydrofluoric acid and digest at 120 °C todryness.

19. Add 6 ml of aqua regia (3 parts nitric acid to 1 part hydrochloricacid), cover and heat to dryness.

20. Repeat steps 18 and 19.

21. Extract with 25 ml of 2.4 N hydrochloric acid and stir.

22. Analyze extract using atomic absorption spectrophotometry (expan-sion =_50).

Second Sequential Extraction (Modified aftermodified after Chao and Zhou, 1983)

Carbonate and Exchangeable Fraction

1. Weigh 1.00 grams of sample into 50 ml centrifuge tube.

2. Add 20 ml of 1.0 M acetic acid and agitate for 2 hours in a mechani-cal shaker.

3. Centrifuge.

4. Analyze extract using atomic absorption spectrophotometry (expansion= 20).

5. Decant off extract and wash remaining sample.

Easily Reducible Fraction

6. Add 40 ml of 0.1 N nitric acid to sample and agitate for 30 minutes

148

Appendix Il -- continued

7. Centrifuge.

8. Analyze extract using atomic absorption spectrophotometry (expansion= 40).

9. Decant off extract and wash remaining sample.

Moderately Reducible Fraction

10. Add 40 ml of 0.25 M hydroxylamine hydrochloride in 0.25 M aceticacid and agitate for 30 minutes in a 50 °C water bath.

11. Centrifuge.

12. Analyze extract using atomic absorption spectrophotometry (expan-sion = 40).

13. Decant off extract and wash remaining sample.

Organic and Sulfide Fraction

14. Add 15 ml of 30% hydrogen peroxide acidified to a pH of 2.

15. Heat at 80 °C.

16. After 1 hour, add an additional 5 ml of acidified 30% hydrogen per-oxide.

17. Continue heating until dry.

18. Extract with 40 ml of 1 M ammonium acetate in 6% nitric acid for30 minutes.

19. Analyze extract using atomic absorption spectrophotometry (expan-sion = 40).

20. Decant off extract and wash remaining sample.

Crystalline Fraction

21. Wash sample into 50 ml teflon beaker and evaporate to dryness.

22. Add 10 ml of concentrated hydrofluoric acid and digest at 120 °C todryness.

23. Add 6 ml of aqua regia (3 parts nitric acid to 1 part hydrochloricacid), cover and heat to dryness.

24. Repeat steps 22 and 23.

149

Appendix II-- continued

25. Extract with 25 ml of 2.5 N hydrochloric acid and stir.

26. Analyze extract using atomic absorption spectrophotometry (expan-sion = 25).

APPENDIX IIIa

ANALYTICAL RESULTS OF THE NITRIC ACID EXTRACTION AND

THE FIRST SEQUENTIAL EXTRACTION ON STREAM SEDIMENTS,

BATAMOTE MOUNTAINS, ARIZONA

150

151

Appendix IIIa -- Analytical Results of the Nitric Acid Extraction and theFirst Sequential Extraction on Stream Sediments, BatamoteMountains, Arizona

Sample Extraction Technique

HNO3 Oxalic Acid HCl -KC103 . HF /Aqua Regia

Cu Cu Fe Cu /Fe (x102) Cu Cu

AJ001S 170 47 3800 1.24 106

AJ002S 90 46 3600 1.28 21

AJ003S 140(150) 52 3300 1.58 51

AJ005S 120(120) 51 5300 0.96 33

AJ007S 110(130) 52 3200 1.63 43

AJ008S 190(180) 76 4300 1.77 61 13

AJOlOS 130(140) 67 5100 1.31 36

AJO11S 60(70)AJ012S 90 32 3300 0.97 33 16

AJ013S 140 44 3800 1.14 38

AJ014S 110 46 3900 1.18 36

AJ015S 100 35 3400 1.03 35 18

AJ016R 140 63 4800 1.31 41

AJ017S 130 53 4700 1.13 43AJ018S 160 64 3600 1.78 58 10

AJ019S 280 109 2600 4.19 104 16

AJO2OS 160 66 3500 1.89 50 10

AJ021S 170(180) --

AJ022S 130 53 4800 1.10 39

AJ023S 200 105 6100 1.72 67

AJ024S 150 55 3600 1.53 48

AJ027S 150 54 4100 1.32 51

AJ028S 140 55 4500 1.22 43AJ029S 170(180)

AJO3OS 130(130)

AJ031S 150 64 5400 1.19 45

AJ032S 90 42 8700 0.48 24

AJ033S 80 29 6000 0.48 30 15

AJ034S 80 37 10,300 0.36 20AJ035S 130 50 6400 0.78 39

AJ036S 110(110)

AJ037S 160 56 4000 1.40 61 15

AJ038S 200 75 3300 2.27 80 15

AJ039S 230 105 4100 2.56 85 13

AJO4OS 170 70 4100 1.71 62 12

Appendix IIIa- continued

Sample

152

Extraction Technique

HNO3 Oxalic Acid HC1 -1(C103

HF /Aqua Regia

Cu Cu Fe Cu /Fe (x102) Cu Cu

AJ041S 160 76 4700 1.62 60 14

AJ042S 140 79 4800 1.65 36

AJ043S 75 33 6200 0.53 22

AJ044S 95 38 7600 0.50 32

A.J045S 80 28 7700 0.36 21

AJ049S 95 33 4700 0.70 25 19

AJ051S 110 40 6200 0.65 26

AJ052S 130 50 6900 0.72 42

AJ053S 120 44 6200 0.71 44

AJ055S 60 24 4700 0.51 16 8

AJ056S 120 55 8000 0.69 27

AJ057S 150 58 4100 1.41 63 12

AJ058S 100 44 10,700 0.41 22

AJ059S 95 37 7500 0.49 25

AJO6OS 90 38 8500 0.45 20

AJ061S 70 26 4200 0.62 21

AJ063S 80 27 3500 0.77 31

AJ064S 70 23 4300 0.53 18

AJ065S 110 44 6000 0.71 33

AJ066S 70 26 6100 0.43 24

AJ067S 120 46 5800 0.79 42

AJ068S 70 27 6200 0.44 25

AJ069S 50 20 4300 0.47 15 18

AJO7OS 60 22 6800 0.32 30

AJ072S 55 22 4300 0.51 16

AJ074S 50 26 5200 0.50 11

AJ075S 65 28 6200 0.45 16

AJ076S 55 21 4800 0.44 14 17

AJ077S 40 17 12,200 0.14 1]

AJ078S 50 18 4500 0.40 13

AJ079S 40 13 5700 0.23 10

AJO8OS 45 13 4600 0.28 12

AJ081S 55 21 7000 0.30 9

AJ082S 45 17 9400 0.18 9

AJ083S 30(25) 10 4100 0.24 3

Appendix IIIa-- continued

Sample

153

Extraction Technique

HNO3 Oxalic Acid HC1 -KC103 HF /Aqua Regia

Cu Cu Fe Cu /Fe (x102) Cu Cu

AJ084S 30(25)AJ085S 80 40 7800 0.51 16

AJ087S 80(70) 35 5300 0.66 30

AJ088S 80(70)AJ089S 75 33 5400 0.61 28

AJO9OS 70 33 7100 0.46 23

AJ091S 95(100) 30 4400 0.68 26 16

AJ092S 90(90)AJ093S 55 23 7100 0.32 16

AJ094S 40 13 4700 0.28 11 10

AJ096S 60(55) 23 9100 0.25 19

AJ097S 70(50)

AJ098S 60(60) 24 10,100 0.24 17

AJ099S 70(50) --AJ100S 60 21 9700 0.22 15

AJ101S 70 30 8600 0.35 20AJ102S 70 23 8800 0.26 19

AJ103S 35(35) 13 7100 0.18 17 14

AJ104S 45(45)AJ105S 50(40) 19 6300 0.30 13

AJ106S 60(60)AJ107S 65 28 5300 0.53 24

AJ141S 95 45 4000 1.13 49AJ142S 75 46 3600 1.28 42

AJ143S 75 50 3400 1.47 42

AJ148S 80 55 4000 1.38 54

AJ149S 100 63 3400 1.85 52

AJ150S 130 70 2800 2.50 60AJ153S 130 80 2600 3.08 71

AJ154S 140 67 2800 2.39 64

All values in parts per million unless otherwise indicated.Parantheses indicate duplicate analyses.

APPENDIX IIIb

ANALYTICAL RESULTS OF THE SECOND SEQUENTIAL EXTRACTION

ON STREAM SEDIMENTS, BATAMOTE MOUNTAINS, ARIZONA

154

Appendix IIIb-- Analytical Results of the Second Sequential Extraction on Stream Sediments, Batamote

Sample

Mountains, Arizona

Density

Separate

Carbonate /Exchangeable

Cu

Fe

Mn

Mineralogie Fraction

Easily Reducible

Cu

Fe

Mn

Moderately Reducible

Cu

Fe

Mn

AJ012S

Bulk

613

40

15

61

40

17

400

50

Heavies

23

52

70

23

260

50

64

1900

50

Slimes

912

65

28

66

50

27

600

65

Lights

620

40

13

61

35

14

400

40

AJ015S

Bulk

411

40

14

62

40

17

400

45

Heavies

12

30

60

19

200

65

51

1600

100

Slimes

612

50

19

65

40

22

600

75

Lights

415

35

13

61

35

12

200

35

AJ019S

Bulk

24

13

55

49

113

35

38

400

25

Heavies

57

56

75

46

270

25

120

1400

60

Slimes

36

16

90

52

121

30

49

700

40

Lights

25

14

60

45

129

30

35

400

15

AJ038S

Bulk

18

11

40

31

142

45

29

400

20

Heavies

65

52

65

46

300

30

180

2800

80

Slimes

33

19

50

50

160

125

65

1400

55

Lights

18

18

45

31

139

40

27

500

20

AJ039S

Bulk

26

13

50

41

114

40

39

500

20

Heavies

56

59

60

46

305

30

125

3000

80

Slimes

46

22

70

67

200

30

75

1100

45

Lights

25

20

50

40

118

35

30

300

15

Appendix IIIh- continued

Sample

Density

Separate

Mineralogic Fraction

Sulfide /Organic

Crystalline

Cu

Fe

Mn

Cu

Fe

Mn

AJ012S

Bulk

9320

15

34

18,000

140

Heavies

240

750

25

59

270,000

2650

Slimes

39

740

30

66

41,000

340

Lights

1230

10

22

13,000

65

AJ015S

Bulk

10

220

10

46

26,000

220

Heavies

180

500

25

105

290,000

2450

Slimes

15

280

20

58

40,000

440

Lights

4170

10

26

18,000

100

AJ019S

Bulk

52

430

10

54

15,000

70

Heavies

460

1350

25

115

105,000

1950

Slimes

200

1100

25

82

31,000

280

Lights

32

580

10

32

12,000

45

AJ038S

Bulk

33

420

15

44

17,000

95

Heavies

520

1500

20

105

65,000

1200

Slimes

240

1100

30

77

51,000

580

Lights

9290

10

36

10,000

40

AJ039S

Bulk

38

450

10

46

18,000

90

Heavies

480

1450

20

95

95,000

1950

Slimes

360

1100

25

115

45,000

580

Lights

14

310

10

40

13,000

60

Appendix Illb -- continued

Sample

Density

Separate

Carbonate /Exchangeable

Cu

Fe

Mn

Mineralogic Fraction

Easily Reducible

Cu

Fe

Mn

Moderately Reducible

Cu

Fe

Mn

AJO4OS

Bulk

15

14

40

27

62

25

31

400

40

Heavies

41

54

65

31

290

35

110

2000

,95

Slimes

27

16

75

53

89

50

70

1000

70

Lights

14

22

40

23

60

30

25

400

30

AJ049S

Bulk

513

45

12

74

50

17

800

55

Heavies

9120

150

15

350

90

42

3800

115

Slimes

512

50

19

62

40

35

900

135

Lights

517

40

11

49

40

14

400

50

AJ069S

Bulk

215

45

898

45

10

600

30

Heavies

5160

170

8335

60

24

3800

90

Slimes

213

65

976

40

22

800

135

Lights

220

45

768

35

8200

20

AJ094S

Bulk

215

45

491

45

7700

40

Heavies

6130

130

7340

55

27

3000

140

Slimes

211

55

973

40

14

1100

19

Lights

221

45

482

40

6500

30

AJ103S

Bulk

223

45

5110

60

81500

85

Heavies

7240

180

9485

60

21

5800

90

Slimes

210

60

12

68

50

17

2000

135

Lights

236

50

593

50

61300

75

Chrysocolla

Standard

230

14

523

17

L(5)

20

N(100)

N(5)

Appendix IIIb -- continued

Sample

Density

Separate

Mineralogie Fraction

Sulfide /Organic

Crystalline

Cu

Fe

Mn

Cu

Fe

Mn

AJO4OS

Bulk

21

340

15

44

17,000

85

Heavies

460

1250

20

90

65,000

1250

Slimes

250

980

30

125

50,000

560

Lights

5250

10

36

13,000

85

AJ049S

Bulk

8420

15

43

26,000

200

Heavies

80

730

30

100

85,000

1500

Slimes

63

1050

35

64

44,000

150

Lights

4390

15

30

21,000

130

AJ069S

Bulk

6360

15

28

23,000

120

Heavies

40

450

15

60

115,000

2400

Slimes

41

420

25

75

55,000

760

Lights

4230

10

22

15,000

70

AJ094S

Bulk

7410

20

26

19,000

90

Heavies

35

420

20

52

75,000

960

Slimes

19

720

40

48

60,000

680

Lights

2370

15

22

17,000

70

AJ103R

Bulk

3450

20

29

28,000

170

Heavies

36

610

30

70

330,000

3050

Slimes

18

890

40

52

43,000

270

Lights

3400

20

17

17,000

60

Chrysocolla

Standard

780

N(5)

5L(1000)

L(5)

All values in

parts per million.

APPENDIX IIIc

ANALYTICAL RESULTS (USING NITRIC ACID EXTRACTION) FOR COPPER

IN THE C -1 AND C -2 FRACTIONS OF HEAVY MINERAL CONCENTRATES,

BATAMOTE MOUNTAINS, ARIZONA

159

160

Appendix IIIc-- Analytical Results (Using Nitric Acid Extraction) for

Copper in the C -1 and C -2 Fractions of Heavy Mineral

Concentrates, Batamote Mountains, Arizona

Sample C -1 C -2 Sample C -1 C -2 Sample C -1 C -2

AJ011C 45 AJ043C 55 AJO81C 20

AJ012C 85 35 AJ044C 20 AJ082C 20

AJOI3C 50 AJ045S 50 AJ083C 15

AJ014C 35 AJ049C 60 20 AJ085C 20

AJ015C 90 20 AJ051C 15 AJ087C 60

AJ016C 45 AJ052C -- 20 AJ089C 50

AJ017C 60 AJ053C 25 AJ090C 55

AJ018C 55 AJ055C 30 AJ091C 35

AJO19C 70 60 AJ056C 30 AJ093C 15

AJ020C 55 AJ057C 100 AJ094C 40 25

AJ021C 65 AJ058C 55 AJ096C 20

AJ022C 50 AJ059C 65 AJ098C 15

AJ023C 70 AJ060C 60 AJ100C 25

AJ024C 55 AJ061C 55 AJIOIC 25

AJ027C 65 AJ063C 45 AJ102C \20

AJ028C 70 AJ064C 25 AJ103C 30 15

AJ029C 45 AJ065C 40 AJ105C 30 15

AJ030C 50 AJ066C 20 AJ107C 20

AJ031C 60 AJ067C 50

AJ032C 50 AJ068C 15

AJ033C 45 AJ069C 45 15

AJ034C 70 AJ070C 10

AJO35Ç 55 AJ072C 15

AJ036C 50 AJ074C 10

AJ037C 65 AJ075C 10

AJ038C 260 120 AJ076C 25

AJ039C 90 85 AJ077C 10

AJ040C 75 45 AJ078C 25

AJ041C 50 AJ079C 10

AJ042C 55 AJ080C 20

All values in parts per million.

REFERENCES

Barton, H. N., Theobald, P. K., Turner, R. L., Eppinger, R. G.,and Frisken, J. G., 1982. Geochemical data for the Ajo two degreequadrangle, Arizona. U.S. Geological Survey Open File Report82 -419. 119 p.

Bryan, K., 1925. The Papago country, Arizona. U.S. GeologicalSurvey Water -Supply Paper 499. 436 p.

Chao, T. T., and Zhou, L., 1983. Extraction techniques for selectivedissolution of amorphous iron oxides from soils and sediments.Soil Science Society of America Journal, 47, p. 225 -232.

Cooper, J. R. Bismuth in the United States. U.S. GeologicalSurvey Mineral Inventory Resource Map MR -22. 19 p., 1 sheet.

DeKalb, C., 1918. Ajo copper mine. Mining and Science Press, 116,p. 115 -116 and 153 -156.

Dixon, D. W., 1966. Geology of the New Cornelia mine, Ajo, Arizona.In: Titley, S. R., and Hicks, C. L., eds. Geology of thePorphyry Copper Deposits -- Southwestern North America, p. 123 -132.

Filipek, L. H., and Owen, R. M., 1978. Analysis of heavy metaldistributions among different mineralogical states in sediments.Canadian Journal of Spectroscopy, 23, p. 31 -34.

Gilluly, J., 1935. Ajo district (Arizona). In: Copper Resourcesof the World, 16th International Geological Congress, 1,p. 228 -233.

, 1937. Geology and ore deposits of the Ajo quadrangle, Ari-zona. Arizona Bureau of Mines Geological Series, No. 9,Bull. 141. 83 p.

, 1942. The mineralization of the Ajo copper district, Ari-zona. Economic Geology, 37, p. 247 -309.

, 1946. The Ajo mining district, Arizona. U.S. GeologicalSurvey Professional Paper 209. 112 p.

Grimes, D. J., and Marranzino, A. P., 1968. Direct- current andalternating- current spark emission spectrographic field for thesemi -quantitative analysis of geological materials. U.S.Geological Survey Circular 591. 6 p.

161

162

Harris, J. 0., 1984. Emplacement and crystallization of the Cor-nelia zoned pluton, Ajo, Arizona: An analysis based on compo-sitional zoning of plagioclase and field relations. UnpublishedM.S. Thesis, The University of Arizona. 78 p.

Haxel, G., Wright, J. E., May, J. E., and Tosdal, R. M., 1980.Reconnaissance geology of the Mesozoic and Lower Cenozoic rockof the Southern Papago Indian Reservation: A preliminary report.Arizona Geological Society Digest, 12, p. 17 -29.

Ingham, G. R., and Barr, A. T., 1932. Mining methods and costs atthe New Cornelia Branch, Phelps Dodge Corporation, Ajo, Arizona.U.S. Bureau of Mines Information Circular 6666. 18 p.

Jones, W. C., 1974. General geology of the northern portion of theAjo Range, Pima County, Arizona. Unpublished M.S. Thesis,

The University of Arizona. 77 p.

Joralemon, I. B., 1914. The Ajo copper mining district. AmericanInstitute of Mining, Metallurgical and Petroleum EngineersTransactions, 49, p. 593 -610.

Kahle, K., Conway, D., and Haxel, G., 1978. Preliminary geologicmap of the Ajo 1° by 2° quadrangle, Arizona. U.S. Geological

Survey Open File Report 78 -1096. 2 sheets.

Klein, D. P., 1982. Residual aeromagnetic map of the Ajo andLukeville 1° by 2° quadrangles, southwestern Arizona. U.S.

Geological Survey Open File Report 82 -599. 1 sheet.

Levinson, A. A., 1980. Introduction to Exploration Geochemistry.Second edition, 924 p.

May, D. J., Peterson, D. W., Tosdal, R. M., LeVeque, R. A., andMiller, R. J., 1981. Miocene volcanic rocks of the Ajo Range,

south -central Arizona. In: Tectonic Framework of the Mojaveand Sonoran Deserts, California and Arizona, p. 65 -66.

National Oceanic and Atmospheric Administration, 1981. Annual

Summary of Climatalogical Data for Arizona, No. 13. 19 p.

Nie, N. H., Hull, C. H., Jenkins, J. G., Steinbrenner, K., andBent, D. H., 1975. Statistical Package for the Social Sciences.

675 p.

Olade, M., and Fletcher, K., 1974. Potassium chlorate -hydrochloric

acid: A sulfide selective leach for bedrock geochemistry.Journal of Geochemical Research, 3, p. 337 -344.

163

Raines, G. L., and Theobald, P. K., 1981. Remote sensing in theAjo 1° by 2° quadrangle, Arizona. In: Geological Survey Re-search, 1981. U.S. Geological Survey Professional Paper 1275,p. 21 -22.

Shafiqullah, M., Damon, P. E., Lynch, D. J., Reynolds, S. J.,Rehrig, W. A., and Raymond, R. H., 1980. K -Ar geochronologyand geologic history of southwestern Arizona and adjacentareas. Arizona Geological Society Digest, 12, p. 201 -260.

Theobald, P. K., and Barton, H. N., 1983. Statistical parametersfor resource evaluation of geochemical data from the Ajo 1° by2° quadrangle, Arizona. U.S. Geological Survey Open File Report83 -734. 44 p.

Wadsworth, W. B., 1968. The Cornelia pluton, Ajo, Arizona.Economic Geology, 63, p. 101 -115.

Ward, F. N., Nakagawa, H. M., Harms, T. F., and VanSickle, G. H.,1969. Atomic- absorption methods useful in geochemical explora-tion. U.S. Geological Survey Bulletin 1289. 45 p.

Wedepohl, K. H., ed., 1969. Handbook of Geochemistry. 6 vols.

Wilson, E. D., Moore, R. T., and Cooper, J. R., 1969. GeologicMap of Arizona. 1 sheet.

32°30

112°50' 4 112° 40'

iN

Tba

Qa

EXPLANATION:

112'50

3025

CONTACT, DASHED WHERE APPROXIMATEOR UNCERTAIN, DOTTED WHERECOVERED.

FAULT, DASHED WHERE APPROXIMATE ORUNCERTAIN, DOTTED WHERE COVERED.

,a.ATTITUDE

O

O

45"2 3 4 MILES

2 3 4 5 KILOMETERS

SCALE: 1:62500

PLATE I- SKETCH GEOLOGIC MAP,BATAMOTE MOUNTAINS, ARIZONA

DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984

g.ha i4itËeve cP,adFnsr 'RoomDEPART : GEOSCIcNCESUNIVERSITY FSZJNA

DESCRIPTIONr4Z

O W1-

OF UNITS

Qa QUATERNARY ALLUVIUM. POORLY SORTEDBY EXTENSIVE

NSIVE ANDVALLEY FILL. CEMENTED IN PLACES BY EXTENSIVE CALICHEDEVELOPMENT.

32° 30'

QTa UNCONSOLIDATED ALLUVIUM PREDATING Oa. FORMS SINUOUS LOWMOUNDS IN THE NORTH AND DISSECTED PEDIMENTS IN THESOUTH.

Tbi BATAMOTE ANDESITE, INTRUSIVE UNIT. APHANI TIC TO FINEGRAINED HYPERSTHENE OLIVINE ANDESITE. OCCURS IN TWODISTINCT PHASES A FINE GRAINED SALT AND PEPPERHYPERSTHENE OLIVINE ANDESITE AND A WEAKLY PORPHYRITIC-APHANITIC OLIVINE ANDESITE. WEATHERS GRAY TO YELLOWON OUTCROP.

Tba BATAMOTE ANDESITE, EXTRUSIVE UNIT. APHANITIC OLIVINEBASALTIC ANDESITE WITH HIGHLY VARIABLE TEXTURES.OCCURS IN FLOWS UP TO 50 FEET THICK, AS A TUFF ANDA VOLCANIC BRECCIA. THE FLOWS TYPICALLY GRADEUPWARDS FROM A GRAY APHANITIC COARSELY FISSILESECTION, THROUGH A MASSIVE INTERMEDIATE ZONE, AND INTOA HIGHLY VESICULAR UPPER SECTION. ALSO INCLUDES

H

rclTb,I

MINOR VOLCANOCLASTIC SEDIMENTS. WEATHERS GRAY, YELLOW,MAROON AND BLACK ON OUTCROP.

BATAMOTE ANDESITE, VENT FACIES. RED TO MAROON VOLCANICBECCIA. TEN CENTIMETER TO ONE METER BLOCKS IN A RED,OXIDIZED, VESICULAR, APHANITIC TO MEDIUM GRAINED

GROUNDMASS.

II

ANDESITIC

w Tai CHILDS LATITE. FLOW BANDED PORPHYRI TIC AUGITE LATITE.l1111 TYPICALLY PORPHYRITIC -APHANITIC WITH SUB- TO ANHEDRAL,

'GRAINEDMEDIUM TO COARSE POTASSIC FELDSPAR PHENOCRYSTSIN A PINK APHANITIC GROUNDMASS. FORMS FLOWS UP TO 80FEET_ THICK. LAHARIC BRECCIA ALSO PRESENT. WEATHERSrFROM WHITE TO MAROON ON OUTCROP. FORMS ROUNDED,POINTED HILLS. .

32° 25'

112° 40'

I32° 30'

112° 50' 45' 112° 40'

112° 50'

EXPLANATION: 32°25'N

0e--/ LINE OF EQUAL CONCENTRATION/ ON PPM)

BOUNDARY OF SAMPLED AREA

1 0 1

45'3 4 MILES

2 3 4 5 KILOMETERS

SCALE: 1:62500

PLATE 10-COPPER, LEACHED USING POTASSIUM PERCHLORATE ANDHYDROCHLORIC ACID, SEQUENTIALLY AFTER AN OXALIC ACID LEACH,

FROM -30 MESH STREAM SEDIMENT, BATAMOTE MOUNTAINS, ARIZONAN, AEevt /Ceadinff DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCES

DEPARTMENT 0F GEOSCIENCES

UNIVERSITY OF ARIZONAUNIVERSITY OF ARIZONA, 1964

32° 30'

32° 25'

112 °40'

32° 30'

112° 50' 45 112° 40'

i EXPLANATION:

112°50'

32° 25

/1 LINE F EQUAL CONCENTRATION

BOUNDARY OF SAMPLED AREA

1 0 4 MILES

1 0 1 2 3 4 5 KILOMETERS

SCALE : 1:62500

PLATE 1 I- COPPER, LEACHED USING NITRIC ACID,IN THE C -2 FRACTION OF HEAVY MINERAL CONCENTRATES,

BATAMOTE MOUNTAINS, ARIZONA`:7h. 04"ntevs %Ceading( WooersOEPARTI'ÍLNT OF GEOSCIENCESUNIVERSITY OF ARIZONA

DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984

112° 40'

32° 30

112°50'

N

45' 112° 40'

112° 50'

EXPLANATION: 32 °251

°o' LINE OF EQUAL CONCENTRATION/ (IN PPM)

./ BOUNDARY OF SAMPLED AREA

45'1 0 1 2 3 4 MILES

1 O 1 2 3 4 5 KILOMETERS

SCALE: 1:62500

PLATE 12- COPPER IN THE C -3 FRACTION OF HEAVYMINERAL CONCENTRATES, BATAMOTE MOUNTAINS, ARIZONA

DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984

CAlevs 9eaC>!inff /'Coon.DEPARTP? i'il ' G[OSCIENCES

UNIVERSI-fiY or ;,RiZOt`iA

32° 30

32° 25'

112° 40'

32° 30'

112° 50' 45, 112° 40'

112° 50'

iEXPLANATION 32 °25'

N ELEMENT CONCENTRATION RANGES(PPM)

1 2Ag L(0.2) -10 15 -30As L(100)-500 700Ba 2000 -5000 7000 -10,000Cu 200 300Mo L(10)-50 70-100Pb 200 -500 700 -2000Sb L(20) 20 -100Sn 100-300 500-1000Zn L(100) -500

OANOMALOUS DRAINAGE BASIN

"°. BOUNDARY OF SAMPLED AREA

1 0 1

2

45,3

2 3 4 5 KILOMETERS

SCALE: 1:62500

PLATE 13- ANOMALOUS SILVER, ARSENIC, BARIUM, COPPER, MOLYBDENUM,LEAD, ANTIMONY, TIN AND ZINC IN THE C -3 FRACTION OF HEAVY

MINERAL CONCENTRATES, BATAMOTE MOUNTAINS, ARIZONAg %a Ctnfç-vF lrCeading' WoQmDEPARTNE:N GEOSCIENCES

UNIVERSITY OF ARIZONA

DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984

32° 30'

112 °50' 45' 112° 40'

\\ J

t

i-

EXPLANATION:

N o SAMPLE SITE

WASH

MINERALS PRESENT

PYRITE

.0 CHALCOPYRITEA MALACHITE

V COVELLITEOARSENOPYRITE

112 °50'

32° 25'

---- --> > \..,-- .r.

_ ,

..--1./ .; i \f / : . (-/*- -)

..Jr- . ?r-e....: - - --(.i- _ _;---l -- `. \.-, /

.. . S._ . ) .). i\ . ..` : \ / o ^..¡.:-. .-...-- .J 1 i _\.\ ../ /.. 1 .1\ --

. ),.:<- .,-i :\.\.."N..------ ' ' ._ -- . . . _ \..

1\ L_..

/ti

. ---.45'

O 1 2 31

. \ /1 Y ..l I

1 / /4 MILES

1 0 1 2 3 4 5 KILOMETERS

SCALE: 1:62500

PLATE 14- PYRITE, CHALCOPYRITE, MALACHITE, COVELLITE ANDARSENOPYITE IN THE C -3 FRACTION OF HEAVY MINERAL CONCENTRATES,

BATAMOTE MOUNTAINS, ARIZONA;14ntdVr /Q.4lidlMff ROCYH

pEF'AR`i`WhlÌ' (.', G"._OSCIENCES

UIdIVERSIT! OF ARIZONA

DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984

32° 30'

32 °25'

112 °40

32° 3Ó

112° 50' 45,

'r~`.

112° 40'

EXPLANATION:

o SAMPLE SITE

r r WASH

MINERALS PRESENT

BARITE

AVO

O

CERRUSITE

GALENA

LEAD SHOT

WULFENITE

CASSITERITE

r `o»

. I:

%

..)4

. , !- ' -- (

r-11 Os...

f -./112°50'

32° 25'

r\O

45'2 3 4 MILES

0 1 2 3 4 5 KILOMETERS

SCALE: 1:62500

PLATE 15- BARITE, CERUSSITE, GALENA, LEAD SHOT, WULFENITE ANDCASSITERITE IN THE C-3 FRACTION OF HEAVY MINERAL CONCENTRATES,

BATAMOTE MOUNTAINS, ARIZONA43.4 ,gevs leadingDEPARTfa9 i ï ; GEOSCIENCESUNIVERSITY OF ARIZONA

DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984

32°3d

112 °50' 45 112° 40'

N

147157

15'4E152 +1s5 161

561 159 6160A, B

138 135137A-D 136

112° 50'

32 °25'

134

254126

9 140139

£144

146

i133

412944131130

54±A,48

47 46

50

12211162

121g 123120119,118

86A.

124125

62 164 126

71A,B

73

.113111

112 110

EXPLANATION:95

25 ROCK CHIP136. OXIDE COATING

1 O

109A,B

£108

165

/1166

115 116

114167

1 2

45"3 4 MILES

1 0 1 2 3 4 5 KILOMETERS

SCALE: 1:62500

PLATE 2 -ROCK CHIP AND OXIDE COATING SAMPLE SITESBATAMOTE MOUNTAINS, ARIZONA

'JAe C4intevs 92eading ieoarwDEPARTMENT ,.;= GEOSCIENCES

- UNIVERSITY OF ARIZONA

DAt/ID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF AR ZONA, 1984

32° 30'

3 2° 25'

112 °40'

32 °30

112 °50' 45, 112° 4d

40 \t\ jA\ 2 5P).\\.

g- \ 0 / 53 52 511.49

544, S `--

5,11,132 )

kL.2 ).' 13,128

< 7,21 ' .41 ;"-

J . 22~ )sy

\1 /"56

.-. 1, ( 7

l\ '.'.

I

69

- \S \ 1 15 \ ) , / \\ 34

N

EXPLANATION:

. WASHES7 SAMPLE SITE

ghe nEevs eadin8 /oamDEPART:T (=7 GEOSCIENCES

UNIVERSITY OF 'r,rILONA

112°50'

32 °25

427`3,36 . ;35 '

Ì

11,, \2

\ ' % '8 .n r 3k '. i75

--...

(.

10.30 )( 85' ts3,84 ( )

c ._ ..,t

(

64c \ 1 ' 1 l J J38..i ` ^ 11 l37 \ l \.. ,s7,8á 89.--- \.r7 ) L. .63. fr

1' 67 .. 98,9g

58 59 "0,127 /60 /r % '101

1

93t921 102

\..',

78

9 100 \ 1 r 1

79

` /103,104 . 182(2 . ..-.c . .1 -..

/...

! - - eo

\ Í ` )i i

\ \,.`..TEN/s4/\ ._fE _.SH"'"\'

' 94 96,9% :. 1. --..

/ ('-1SIK .'..LÇHUgAo

1 0 1

107 : n05, / /Y- . -_ i'.

106117 --, . '.2

45'3 4 MILES

1 O 1 2 3 4 5 KILOMETERS

SCALE: 1:62500

PLATE 3- DRAINAGE MAP SHOWING STREAM SEDIMENTAND HEAVY MINERAL CONCENTRATE SAMPLE SITES,

BATAMOTE MOUNTAINS, ARIZONADAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCES

UNIVERSITY OF ARIZONA, 1984

32° 30'

32° 25

112 °401

32° 30

112° 50' 45' 112° 40'

40.39

+

' % `- -7, 2141¡ 11J23`_1 r i42 \ \ I 24

/,_,720

N

EXPLANATION:

\

55 +5153 52 4544 6856

/

)\_,49/\l

,11,1328 7

13 128

rc\\ \ 7 691 1

1 I

(

27 --\36

34131 14f 15 l )

28\ J (----, y-I'l

721

16

\I ' ,8,2 -I

"941.-\, t_,. f I

\ \,/ ) /6 '\ l ( -- ).8,54.84/10, 30 I

1 1 ,./., - r64 > `>v

38<i37 \- f--,, / /1

\ C 78 88¡g/I /'67

\ \ / 7775\ `~ /

57¡___ 1 63? \-\61

580' -40_,/'

7 SAMPLE SITE

DRAINAGE BASIN BOUNDARY

o

59 t_ f 90, 12760 l.

93 t91,92 \/ -- 81

!103, 104 r"-82

\394 96,97

1 2

45,3 4 MILES

1 0 1 2 3 4 5 KILOMETERS

PLATE 4- STREAMSAMPLE

431'¢ .a4ritevg CPeading 92oa,yDEPAR M; CEúSCIENCES11fVIVFRSITY OF ARI7nNa

SCALE: 1 :62500

SEDIMENT AND HEAVY MINERAL CONCENTRATESITES, SHOWING AREAS OF INFLUENCE,BATAMOTE MOUNTAINS, ARIZONA

DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984

32° 30'

32° 25'

112 °40'

32° 30

112°50' 45, 112°40'

N

112° 50

EXPLANATION: 32° 25

LINE OF EQUAL CONCENTRATION(IN PPM)

BOUNDARY OF SAMPLED AREA

1 0 1 2 3 4 MILES

0 1 2 3 4 5 KILOMETERS

SCALE: 1:62500

PLATE 5- COPPER, LEACHED USING NITRIC ACID,FROM -30 MESH STREAM SEDIMENT,

BATAMOTE MOUNTAINS, ARIZONA4Eí4'4a riti CF

ding 9eoóm DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY

OF ARIZONAUNIVERSITY OF ARIZONA, 1984

32 °30

112 °50' 45 112° 40'

iN

EXPLANATION:

112° 50'

32° 25'

BOO/ LINE OF EQUAL CONCENTRATION/ (IN PPM)/ BOUNDARY OF SAMPLED AREA

1 0 1

1 0 1

2

45,3 4 MILES

2 3 4 5 KILOMETERS

SCALE: 1:62500

PLATE 6 SILVER IN -30 MESH STREAM SEDIMENT,BATAMOTE MOUNTAINS, ARIZONA

`1e cAtevs,-

jDEPlR7ivi{i7 eading

,COOn,

CGEOSCIcNCESUNIVERSITY

OF ARIZONA

DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984

32 °30'

32° 25'

112 °40'

32 °30/

112 °50 45, 112 °40

N

112 °50'

EXPLANATION: 32 °25

° LINE OF EQUAL CONCENTRATION/ (IN PPM)y BOUNDARY OF SAMPLED AREA

1 O 1 2 4 MILES

1 0 1 2 3 4 5 KILOMETERS

SCALE: 1 :62500

PLATE 7- BISMUTH IN -30 MESH STREAM SEDIMENT,BATAMOTE MOUNTAINS, ARIZONA

é cri cvs Vading WoonDEPARTM_NT CF. GEOSCIENCESUNIVERSITY OF ARIZONA

DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIECESUNIVERSITY OF ARIZONA, 1984

112°40'

32° 30'

112°50' 45, 112° 45'

EXPLANATION 32 °25

N ELEMENT CONCENTRATION(PPM)

1

RANGES

2Mo L(5)-5 7 -10Pb 100-150 200 -300Sn L(5) -5 7 -10Zn 50 70

4

OANOMALOUS DRAINAGE BASINS

BOUNDARY OF SAMPLED AREA

1 0

1 0 1 2 3 4 5 KILOMETERS

SCALE: 1:62500

PLATE 8- ANOMALOUS MOLYBDENUM, LEAD, TIN AND ZINCIN -30 MESH STREAM SEDIMENT, BATAMOTE MOUNTAINS, ARIZONA

isadevs Weadi»DEPARTrviIPT ;;,-

t7 CooUNIVERSITY OF ARIZONA

DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984

32° 30

112° 50' 45, 112° 40'

N

112° 50'

EXPLANATION: 32° 2

°° LINE OF EQUAL CONCENTRATIONRATIOS (Cu /Fe x 10 -2)BOUNDARY OF SAMPLED AREA

1 O 1 2

32° 30'

32°25'

45' 112°40'3 4 MILES

1 0 1 2 3 5 KILOMETERS

SCALE: 1:62500

PLATE 9- COPPER (NORMALIZED TO IRON), LEACHED USING OXALIC ACID,FROM -30 MESH STREAM SEDIMENT,

ghe :4nfevs `12eading %ooI BATAMOTE MOUNTAINS, ARIZONADEPARTMENT OF GEOSCIENCES DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA UNIVERSITY OF ARIZONA, 1984

THE SIGNIFICANCE OF A WIDESPREAD STREAM SEDIMENT COPPER ANOMALY

IN THE BATAMOTE MOUNTAINS, PIMA COUNTY, ARIZONA

by

David Lowell Huston

A Thesis Submitted to the Faculty of the

DEPARTMENT OF GEOSCIENCES

In Partial Fulfillment of the RequirementsFor the Degree of

MASTER OF SCIENCES

In the Graduate College

THE UNIVERSITY OF ARIZONA

1 9 8 4

STATEMENT BY AUTHOR

This thesis has been submitted in partial fulfillment of re-quirements for an advanced degree at The University of Arizona and isdeposited in the University Library to be made available to borrowersunder the rules of the Library.

Brief quotations from this thesis are allowable without specialpermission, provided that accurate acknowledgement of source is made.Requests for permission for extended quotation from or reproduction ofthis manuscript in whole or in part may be granted by the head of themajor department of the Dean or the Graduate College when in his or herjudgement the proposed use of the material is in the interests ofscholarship. In all other instance however, permission must beobtained from the author. l n

This thes

SIGNED:

APPROVAL BY THESIS DIRECTOR

Ms been approved f the date shown below:

S. R. TITLEYProfessor of Geosciences

ACKNOWLEDGEMENTS

This research was undertaken with the assistance of many indivi-

duals associated with the U. S. Geological Survey and The University of

Arizona. First of all, I would like to thank Spencer Titley and Chris

Eastoe of The University of Arizona, William Payne of Getty Mining, and

Henry Alminas of the U. S. Geological Survey for their criticisms and

assistance during the fieldwork and the preparation of this paper. I

would especially like to thank Paul Theobald of the U. S. Geological

Survey for suggesting the topic, for his invaluable assistance and advice

in conducting the research, and for providing funding.

Additionally, I acknowledge the help of T. T. Chao and Lori

Filipek of the U. S. Geological Survey, Burt Lamoureux, and all the

other individuals who helped me in analyzing my samples. A special thanks

must be given to E. F. Cooley of the U. S. Geological Survey for reading

my spectroscopic films.

Finally, I thank my father Richard Huston, my step- brother Larry

Green, and my friends Roy Jemison and Greg Zeihen their assistance in

collecting samples. Without the help of all these people, the completion

of this project would have taken much longer, and the research would not

have been as complete.

iii

TABLE OF CONTENTS

Page

LIST OF ILLUSTRATIONS viii

LIST OF TABLES xi

LIST OF PLATES xii

ABSTRACT xív

INTRODUCTION, PURPOSE AND SCOPE OF THE STUDY 1

LOCATION, PHYSIOGRAPHY AND CLIMATE 4

PREVIOUS WORK 8

Geology 8

Surficial Geochemistry 9

Geophysics 10

REGIONAL GEOLOGY 11

Stratígraphy 11

Structure 17

LOCAL GEOLOGY 19

Stratígraphy 19

Childs Latíte 19

Distribution and Physiography 19

Petrology and Mineralogy 20Batamote Andesite -- Extrusive Facies 22

Distribution and Physiography 22

Petrology and Mineralogy 22

Batamote Andesite- -Vent Facies 24Distribution and Physiography 24Petrology 24

Batamote Andesite -- Intrusive Facies 27Distribution and Physiography 27Petrology and Mineralogy 27

iv

TABLE OF CONTENTS -- Continued

V

Page

Older Alluvium 28

Quaternary Alluvium 31

Structure 31

Faulting 31

Folding 31

Alteration 32

LITHOGEOCHEMISTRY 33

Major and Minor Elements 33

Trace Elements 35

R -Mode Factor Analysis 37

STREAM SEDIMENT GEOCHEMISTRY 44

Preliminary Phase 44

Main Phase 47

Field Methods 47

Sample Preparation 47

Results of the Hot Nitric Acid Extraction 48

Results of Semi -Quantitative Emission. SpectroscopicAnalysis 48

Copper 50Silver and Bismuth 50Other Base Metals 53

R -Mode Factor Analysis 53

Results of the First Sequential Extraction 59Oxalic Acid Leach 61

Potassium Perchlorate -Hydrochloric Acid Leach . . . 62

Aqua Regia /Hydrofluoric Acid Leach 63

Summary 64Results of the Second Sequential Extraction 64

The Distribution of Iron and Manganese 66

The Distribution of Copper in the CrystallineFraction 68

The Distribution of Copper in the Carbonate andExchangeable Fraction 68

The Distribution of Copper in the Easily ReducibleFraction 68

The Distribution of Copper in the ModeratelyReducible, and Sulfide and Organic Fractions 69

vi

TABLE OF CONTENTS -- Continued

Page

Summary 69

Summary 70

Follow -Up Phase 71

Summary of the Information Derived From Stream Sediments . . 71

INTERPRETATIONS FROM HEAVY MINERAL CONCENTRATES 75

Field Methods 75

Sample Preparation 76

Analysis of the C -1 and C -2 Fractions 77

Spectroscopic Analysis of the C- tion 79

Copper 80

Other Elements 82

Mineralogy of the C -3 Fraction . 87

The Concentration of Copper in Pyr ains 89

Summary 89

OTHER RESULTS 92

SUMMARY OF DATA PRESENTED, EVALUATION OF WOR !YPOTHESES, ANDCONCLUSIONS 94

Evaluation of Working Hypotheses . . 96

Airborne Contamination from a Sm, in Ajo 96

Abnormally High Background in th mote Andesíte 96

Primary Mineralization . . . . 97

Dispersion Along Normal Faults 97

Contamination of the Batamote to During itsEruption 100

Conclusions l00

APPENDIX Ia: ANALYTICAL RESULTS (USING SEMI -QUANTITATIVE EMISSIONSPECTROSCOPY) FOR ROCK CHIP SAMPLES, BATAMOTE MOUNTAINS,ARIZONA 102

TABLE OF CONTENTS -- Continued

APPENDIX Ib: ANALYTICAL RESULTS (USING SEMI -QUANTITATIVE EMISSIONSPECTROSCOPY) FOR STREAM SEDIMENTS, BATAMOTE MOUNTAINS,ARIZONA

V11

Page

112

APPENDIX Ic: ANALYTICAL RESULTS (USING SEMI -QUANTITATIVE EMISSIONSPECTROSCOPY) FOR THE C -3 FRACTION OF HEAVY MINERALCONCENTRATES, BATAMOTE MOUNTAINS, ARIZONA 128

APPENDIX Id: ANALYTICAL RESULTS (USING SEMI -QUANTITATIVE EMISSIONSPECTROSCOPY) FOR OXIDE COATINGS ALONG JOINTS AND FRACTURES,BATAMOTE MOUNTAINS, ARIZONA 141

APPENDIX II: ANALYTICAL TECHNIQUES 145

APPENDIX IIIa: ANALYTICAL RESULTS OF THE NITRIC ACID EXTRACTIONAND THE FIRST SEQUENTIAL EXTRACTION ON STREAM SEDIMENTS,BATAMOTE MOUNTAINS, ARIZONA 150

APPENDIX IIIb: ANALYTICAL RESULTS OF THE SECOND SEQUENTIALEXTRACTION ON STREAM SEDIMENTS, BATAMOTE MOUNTAINS, ARIZONA . 154

APPENDIX IIIc: ANALYTICAL RESULTS (USING NITRIC ACID EXTRACTION)FOR COPPER IN THE C -1 AND C -2 FRACTIONS OF HEAVY MINERALCONCENTRATES, BATAMOTE MOUNTAINS, ARIZONA 159

REFERENCES 161

LIST OF ILLUSTRATIONS

Figure

Page

1. Location of study area 6

2. Photograph, looking east, of the high point, BatamoteMountains 7

3. Stratigraphy of the Ajo area 12

4. Simplified geologic map of the Ajo and Sikort Chuapo 15- minutequadrangles, Arizona 13

5. Photomicrograph of Childs Latite 21

6. Photomicrograph of the basal section of a typical flow,Batamote Andesite 25

7. Photomicrograph of the upper unit of a typical flow, BatamoteAndesíte 26

8. Photomicrograph of the dioritic unit of the intrusive facies

of the Batamote Andesite 29

9. Photomicrograph of the porphyritíc unit of the intrusivefacies of the Batamote Andesite 30

10. Histogram showing the distribution of copper in theBatamote Andesíte 39

11. Histogram showing the distribution of lead in the BatamoteAndesíte 39

12. Histogram showing the distribution of zinc in the BatamoteAndesíte 40

13. Factor loadings for 18 elements from R -Mode factor analysisof the Batamote Andesite 42

14. Histogram showing the distribution of copper (extractedusing hot nitric acid) in -30 mesh stream sediments 49

viii

LIST OF ILLUSTRATIONS -- Continued

Figure

ix

Page

15. Histogram showing the distribution of silver (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh streamsediment 51

16. Histogram showing the distribution of bismuth (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh streamsediment 51

17. Histogram showing the distribution of molybdenum (analyzedusing semi -quantitative emission spectroscopy) in -30 meshstream sediment 54

18. Histogram showing the distribution of lead (analyzed usingsemi- quantitative emission spectroscopy) is -30 mesh streamsediment 54

19. Histogram showing the distribution of tin (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh streamsediment 55

20. Histogram showing the distribution of zinc (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh streamsediment 55

21. Factor loadings for 19 elements from R -Mode factor analysisof stream sediments 57

22. Histogram showing the distribution of copper normalized toiron (extracted using hot oxalic acid) in -30 mesh streamsediments 60

23. Histogram showing the distribution of copper (extractedsequentially using potassium perchlorate and hydrochloricacid after oxalic acid) in -30 mesh stream sediments 60

24. Distribution of copper among mineralogic and density fractionsof selected stream sediment samples, Batamote Mountains,Arizona 67

25. Distribution of copper normalized to iron (extracted usingoxalic acid) in -30 mesh stream sediment samples upstreamof sample AJ003S 72

LIST OF ILLUSTRATIONS -- Continued

Figure

X

Page

26. Distribution of copper normalized to iron (extracted usingoxalic acid) in -30 mesh stream sediment samples upstreamof sample AJ039S 73

27. Histogram showing the distribution of copper (extractedusing hot oxalic acid) in the C -2 fraction of heavy mineralconcentrates 78

28. Histogram showing the distribution of copper in thenon - magnetic fraction (C -3) of heavy mineral concentrates . 81

29. Histogram showing the distribution of silver in thenon - magnetic fraction (C -3) of heavy mineral concentrates . 83

30. Histogram showing the distribution of arsenic in thenon -magnetic fraction (C -3) of heavy mineral concentrates . 83

31. Histogram showing the distribution of barium in thenon -magnetic fraction (C -3) of heavy mineral concentrates . 84

32. Histogram showing the distribution of molybdenum in thenon -magnetic fraction (C -3) of heavy mineral concentrates . 84

33. Histogram showing the distribution of lead in thenon -magnetic fraction (C -3) of heavy mineral concentrates . 85

34. Histogram showing the distribution of antimony in thenon -magnetic fraction (C -3) of heavy mineral concentrates . 85

35. Histogram showing the distribution of tin in thenon -magnetic fraction (C -3) of heavy mineral concentrates . 86

36. Histogram showing the distribution of zinc in thenon - magnetic fraction (C -3) of heavy mineral concentrates . 86

LIST OF TABLES

Table

Page

1. Summary of major element oxide analyses of the Childs Latiteand the Batamote Andesite 34

2. Summary of emission spectroscopic analyses on the ChildsLatite and Batamote Andesite 36

3. Results of R -Mode principal factor analysis with iterationsafter varimax rotation for the extrusive facies of theBatamote Andesíte, Batamote Mountains, Arizona 41

4. Concentrations of copper in selected stream sediment samplesrelative to particle size 46

5. Replicate stream sediment sample pairs 47

6. Results of R -Mode principal factor analysis with iterationsafter varimax rotation for -30 mesh stream sediments,Batamote Mountains, Arizona 56

7. Samples analyzed using five -step sequential analysis 66

8. Magnetic fractions and representative mineralogy 76

9. Replicate heavy mineral concentrate sample pairs 80

10. Concentrations of copper in pyrite grains from selectedheavy mineral concentrate samples 90

xi

LIST OF PLATES

Plate

1. Sketch Geologic Map, Batamote Mountains, Arizona

2. Rock Chip and Oxide Coating Sample Sites, Batamote Mountains, Arizona

3. Drainage Map Showing Stream Sediment and Heavy Mineral ConcentrateSample Sites, Batamote Mountains, Arizona

4. Stream Sediment and Heavy Mineral Concentrate Sample Sites, ShowingAreas of Influence, Batamote Mountains, Arizona

S. Copper, Leached Using Nitric Acid, from -30 Mesh Stream Sediment,Batamote Mountains, Arizona

6. Silver in -30 Mesh Stream Sediment, Batamote Mountains, Arizona

7. Bismuth in -30 Mesh Stream Sediment, Batamote Mountains, Arizona

8. Anomalous Molybdenum, Lead, Tin and Zinc in -30 Mesh Stream Sediment,Batamote Mountains, Arizona

9. Copper (Normalized to Iron), Leached Using Oxalic Acid, from -30Mesh Stream Sediment, Batamote Mountains, Arizona

10. Copper, Leached Using Potassium Perchlorate and Hydrochloric Acid,Sequentially After an Oxalic Acid Leach, from -30 Mesh StreamSediment, Batamote Mountains, Arizona

11. Copper, Leached Using Nitric Acid, in the C -2 Fraction of HeavyMineral Concentrates, Batamote Mountains, Arizona

12. Copper in the C -3 Fraction of Heavy Mineral Concentrates, BatamoteMountains, Arizona

13. Anomalous Silver, Arsenic, Barium, Copper, Molybdenum, Lead,Antimony, Tin and Zinc in the C -3 Fraction of Heavy MineralConcentrates, Batamote Mountains, Arizona

14. Pyrite, Chalcopyrite, Malachite, Covellité and Arsenopyrite in theC -3 Fraction of Heavy Mineral Concentrates, Batamote Mountains,Arizona

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LIST OF PLATES -- Continued

Plate

15. Barite, Cerussite, Galena, Lead Shot, Wulfenite and Cassiteritein the C -3 Fraction of Heavy Mineral Concentrates, BatamoteMountains, Arizona

ABSTRACT

To determine the cause and distribution of a widespread copper

anomaly in the Batamote Mountains discovered by the U. S. G. S. (Barton

and others, 1982), detailed stream sediment and heavy mineral concentrate

sampling and reconnaissance geologic mapping were undertaken in the area.

The stream sediments yielded two anomalous areas characterized

by copper, silver and bismuth, separated by a narrow trough of low values.

The anomalous values are spatially associated with a series of northerly

trending normal faults.

The anomalous copper is held predominantly in iron and manganese

oxides, but a significant portion is held in a reduced form (probably

organics). Analysis of pyrite grains from heavy mineral concentrates for

copper indicates that pyrite cannot contribute enough copper to cause the

observed anomalies.

Analysis of the non -magnetic fraction of heavy mineral concen-

trates produced a similar anomaly pattern for copper, but no enhancement

was realized relative to stream sediments. This analysis also yielded

three other anomalous areas characterized by a volatile element assem-

blage, a tin -molybdenum assemblage and a silver- arsenic -molybdenum assem-

blage, respectively. The cause of these anomalies remains problematic.

The primary anomaly is best explained as the result of disper-

sion along normal faults. The original source of the metals in the normal

faults could not be absolutely determined in the present study.

xiv