a study of uranium favorability of cenozoic...
TRANSCRIPT
A STUDY OF URANIUM FAVORABILITYOF CENOZOIC SEDIMENTARY ROCKS
BASIN AND RANGE PROVINCE,ARIZONA
Part IGeneral Geology and Chronology of Pre-late Miocene
Cenozoic Sedimentary Rocks
byRobert Scarborough and Jan Carol Wilt
Arizona Geological SurveyOpen-File Report 79-1
1979
Arizona Geological Survey416 W. Congress, Suite #100, Tucson, Arizona 85701
U. S. GEOLOGICAL SURVEY OPEN FILE REPORT 79-1429
This report is preliminary and has not been editedor reviewed for conformity with Arizona Geological Survey standards
FOREWORD
This report by Robert Scarborough and Jan Carol Wilt summarizes the
results of a study made for the U,S. Geological Survey jointly by the
Bureau of Geology and Mineral Technology and the Laboratory of Isotope
Geochemistry, College of Earth Sciences, University of Arizona, under
Grant No. 14-08-0001528. Age dating by the K/Ar method was cost~shared
with' NSF Grant No. EAR78-ll535 which supports volcanic rock studies by
the Laboratory of Isotope Geochemistry.
It is considered that this report adequately fulfills the agreement
objectives.
Principal Investigator: H. Wesley Peirce, Principal GeologistGeological Survey BranchBureau of Geology and Mineral TechnologyUniversity of Arizona, Tucson
(, Co-Principal Investigator: Paul E. Damon, Chief ScientistLaboratory of Isotope GeochemistryDepartment of GeosciencesCollege of Earth SciencesUniversity of Arizona, Tucson
Abstract •.•.
CONTENTS
" ... " ..... "
Page1
Introduction .General statementPurpose and scopeAcknowledgmentsLocation and physiographicApproach .•....•
• • • • • ! •
setting .
• 1 0 I.
333445
General Cenozoic geology of Basin and Range Province sediments .General statement . . . . . . • . . • . •Group I localities with radioactive anomalies
Mineta Formation . . • .Cardinal Avenue sediments .Teran Basin sequenceSwisshelm Valley . . . .Adair Park Redbeds . . . .East side of Plomosa MountainsMuggins Mountains . . . . .Western Gila Bend Mountains . .
Group I localities without known radioactive anomalies .Pantano Formation • . .Helmet Fanglomerate . •Threelinks ConglomerateWhitetail Conglomerate • . . •Redbeds of Babocomari RanchRedbeds of Three Buttes •Hackberry Formation . . .Apsey ConglomerateLocomotive Fanglomerate .Sil Murk Formation ...•Clanton Hills section .Osborne washPhoenix region . . . •
7799
10111213141516
1717181818191919202020212122
Group II localities withBlack Butte •New River . • . . .Cave Creek ..•..Rifle Range sectionArtillery FormationWickenburg area . .Lincoln Ranch beds
radioactive anomalies . 2525262727283031
,CONTENTS CONT'D
Group II localities without known anomalies .Harcuvar Mountains-Bullard Peak . . • .
Page3232
Group III localities withHorsehoe Dam . • • • .Lake Pleasant regionBig Sandy Valley • •
radioactive anomalies 33333436
Group III localities without known radioactive anomaliesHassayampa River . • • • • • . . • . . .. ••••
Others - Without known radioactive anomaliesBiery # 1 State . . . • . . . • • • • . .
3737
3838
Cenozoic sediments - structure - uranium - favorability exploration • . • • .
General statement . . • •Pre-basin fill Cenozoic sediments
Summary and conclusion
References cited
Illustrations .
Tables
. "
393939
45
49
55
91
. .
Figure
Figure A.Figure B.Figure :t..Figure 2.Figure 3.Figure 4.Figure 5.Figure .6.Figure 7.Figure ,_8.Figure "9.Figure 10.Figure 11.Figure 12.Figure 13.Figure 14.Figure 15.Figure 16.Figure 17.
Figure 18.Figure 19.Figure 20.Figure 21.Figure 22.Figure 23.Figure 24.Figure 25.Figure 26.Figure 27.Figure 28.
Figure 29.Figure 30.Figure 31.Figure 32.Figure 33.Figure 34 •.
Tables
Table 1.
Table 2.
ILLUSTRATIONS
Index map of cross-sections • . . . . . • . . • . • • •Index map of uranium localities . . . . . • . . • . . .Cross-section - Tucson Basin to Galiuro Mountains • • .Cross-section - Mineta FormationCross-section - Teran Basin . . . • • .Cross-section - Adair Park redbedsCross-section - Northern Plomosa MountainsCross-section - Western Gila Bend Mountains •Cross-section - Swisshelm Valley . • . . . .Cross-section - Clanton Hills . . . • . • •Cross-section - Locomotive fanglomerate, AjoCross-section - Sil Murk beds at Gila BendCross-section - Metropolitan PhoenixCross-section - Near Fort McDowell, lower Verde River .Cross-section - Osborne Wash, near Parker • • .Cross-section - Black Butte, western Vulture Mtns.Cross-section - New River Mesa area, Cave CreekCross-section - New River • • . . • . • . . . •Cross-section - Rifle range section at Carefree
Highway and 1-17 . • • • . . • • .Cross-section - Artillery formation - Masterson claimsCross-section - Artillery formation - Lucky four claimsCross-section - Harcuvar Mtns., Rudy Pass ....•Cross-section - Harcuvar Mtns., Bullard PeakCross-section - Horseshoe Dam, lower Verde RiverCross-section - Lake Pleasant, Agua Fria RiverCross-section - Big Sandy beds near Wikieup . . .Cross-section - Big Sandy beds - Tule Wash sectionCross-section - Hassayampa River at Wickenburg • • • .Physiographic provinces of Arizona . . • . . . . .Tertiary dip directions and gneissic-crystallinecomplexes in Arizona . . . • . . • • . • . .Prospecting permits for uranium, 1975-1978Space-time plot for Arizona Tertiary deposits .Floor of Cenozoic deposits in Arizona • •. .•.•.Alkaline rocks in Arizona . . . • • • • • . • . . • •Transport directions of Tertiary sedimentsMap of post-15 m.y. old cover rocks ..•••
LIST OF TABLES
Uranium in pre-basin fill Tertiary sedimentsin the Basin and Range Province of Arizona .
Potassium-argon ages of volcanic rocks determinedfor this study . . • • • . • • • . . . . . . .
Page
555657585960616263646566676869707172
7374757677787980818283
84858687888990
91
98
ABSTRACT
This study focuses attention on Cenozoic sedimentary rocks in the
Basin and Range Province of Arizona. The known occurrences of uranium
and anomalous radioactivity in these rocks are associated with sedi~
ments that accumulated in a low energy environment characterized by
fine~grained clastics, including important tuffaceous materials, and
carbonate rocks. Most uranium occurrences in these rocks appear to be
stratabound.
Emphasis was placed on those sedimentary materials that pre~date
the late Cenozoic Basin and Range disturbance. They are deformed and
crop out on pedimented range blocks and along the province interface
with the Transition Zone. Three tentative age groups are recognized:
Group I ~ Oligocene, pre~22 m.y., Group II ~ early Miocene - 22 m.y.
~ 16 m.y., and Group III ~ middle Miocene ~ 16 m.y. to 13~10.m.y.
Regionally, these three groups contain both coarse to fine~grained red
clastics and low energy lighter colored "lacustrine" phases.
Each of the three groups has been the object of uranium exploration.
Group II, the early Miocene strata, embraces the Anderson Mine - Artillery
region~. host rocks and also the New River - Cave Creek early Miocene
beds along the boundary with the Transition Zone.
These three groups of rocks have been tectonically deformed to the
extent that original basins of deposition cannot yet be reconstructed.
However, they were considerably more extensive in size than the late
Cenozoic basins the origin of which deformed the former.
Group II rocks are judged to be of prime interest because of:
(1) the development and preservation of organic matter in varying
lithologies, (2) apparent contemporaneity with silicic volcanic
centers, (3) influence of Precambrian crystalline rocks, and (4)
relative outcrop continuity near the stable Transition Zone.
The Transition Zone, especially along its boundary with the
Basin and Range Province, needs additional geologic investigation,
especially as regards the depositional continuity of Group II sedi
ments.
INTRODUCTION
GENERAL STATEMENT
This report summarizes the uranium related highlights of a general
geologic and age-dating study conducted on pre-10 to 13 m.y. old sedi
mentary rocks of the Basin and Range Province of Arizona. The project
began June 1, 1978, and ended April 30, 1979. The study was carried out
under the office of Energy Resources, United States Geological Survey,
Denver Federal Center, Denver, CO 80225.
The English system of measurement is used throughout this report.
PURPOSE AND SCOPE
This field study is Part I of a larger study designed to assess the
uranium favorabi1ity of Cenozoic sedimentary rocks of the Basin and Range
province of Arizona. Part I is intended to be an overview of the general
geology of pre-10 to 13 m~y. old pre-Basin and Range disturbance, Tertiary
sedimentary rocks with emphasis on those having known uranium occurrences
or anomalous radioactivit~. A major objective was the collection
and K/Ar dating of 25 volcanic units suitable for providing chronological
information regarding closely associated Cenozoic stratigraphic sequences.
Other objectives included:
(1) establishment of the character, tectonic position, and state of
deformation of the various sedimentary packages,
(2) correlation of Cenozoic events,
(3) compilation of an appropriate bibliography,
(4) evaluation of problems and avenues for additional research, and
(5) preparation of data for an eventual Bureau of Geology and Min-
eral Technology publication.
-3-
ACKNOWLEDGMENTS
In a problem so regionally extensive it is essential that advantage
be taken of various assists wherever possible. Assists in the field were
generously provided by Principal Investigator H. W. Peirce, Professor Don
Clay of Arizona Western College, Stephen J. Reynolds, University of Ari
zona, prospectors Tom Howell and Harold Best, and consultant Richard
Cribbs. Consultant Edgar B. Heylmun, Tucson, provided important guidance.
The age-dating work was conscientiously guided by Dr. M. Shafiqullah of
the Laboratory of Isotope Geochemistry, University of Arizona. Discussion
of a diversity of geologic problems with colleagues H. Wesley Peirce and
Stanley B. Keith proved indispensable. U.S. Geological Survey project
officer James K. Otton willingly provided important information. Both the
State of Arizona and the University of Arizona provided valuable supports
not elsewhere acknowledged.
LOCATION AND PHYSIOGRAPHIC SETTING
It is customary to subdivide Arizona into physiographic-geologic
provinces. The subdivision used here is illustrated in Figure 27 (All
figures are together near the end of the report). It includes the Colora
do Plateau Province to the northeast and the Basin and Range Province to
the southwest. In the central part of the state these are separated
by a Transition Zone. The southwestern boundary of the Plateau is fre
quently called the Mogollon Rim.
Whereas the Plateau region is characterized by an erosLonally stripped
surface cut upon outcropping Mesozoic-Paleozoic sedimentary rocks, the
Basin and Range country is typified by alternating ranges and basins.
Ranges consist of rocks of sedimentary, igneous, and metamorphic origin
A-
whereas intervening valleys (basins) frequently are underlain by thou
sands of feet of sedimentary materials that infi11ed the basins as they
came into existence as a manifestation of the Basin and Range disturbance
13-10 m.y. ago. Our principal concern here is the nature of
the Cenozoic geologic history prior to the Basin and Range disturbance.
The Transition Zone, consisting largely of Precambrian crystalline
and Tertiary volcanic and sedimentary rocks, contains a few mountains and
valleys. Its post-Precambrian rocks are not severely tectonically dis
turbed although the region has undergone some late Cenozoic normal
faulting. This zone, as regards the Tertiary sedimentary record, bears
a closer relationship to the Basin and Range Province than it does the
Colorado Plateau Province.
APPROACH
A review of the uranium favorabi1ity of Cenozoic sedimentary rocks of
the Basin and Range Province in Arizona was stimulated by several factors:
(1) a growing interest in exploring for uranium in this part of
Arizona,
(2) uranium occurrence precedents place emphasis on the Cenozoic
sedimentary rocks, and
(3) a general paucity of regionally oriented geologic data suitable
for developing an overview of Cenozoic geologic history.
For the Phase I study it was decided that attention would be focused
on what is here called the pre-basin fill sedimentary sequences. In
effect, this limited the study to the older, more deformed, discontinu
ous, scattered, erratically preserved sections exposed in either range
structural blocks or along the more stable southern edge of the
-s~
Transition Zone. Emphasis was placed on those sections associated with
previously published uranium occurrence data especially the AECls Pre
liminary Reconnaissance Reports (PRR). An attempt was made to extract
the geologic highlights including: lithology, thickness, state of defor
mation, extent of outcrop, transport directional parameters, relationship
to volcanic products, and age through all available data including new
K/Ar dating done for this project. Background radioactivity was checked
and anomalous readings noted. These data were synthesized and appropriate
regional generalizations made. Our basic data and preliminary conclusions
are depicted in this report. Although extensive mapping was not a part of
this general study, 26 sketch geologic sections were constructed and con
stitute an important part of this report.
All radiometric readings were made with a Geometries model GR-IOIA
single channel gamma ray scintillometer. Readings generally were taken
against or very close to a given rock exposure. Readings judged to be
twice background or more were considered anomalous.
K/Ar age dates are listed on Table 2 and the sketch geologic sections
appear as Figures 1 through 26.
-6~
GENERAL CENOZOIC GEOLOGY OFBASIN AND RANGE flROVINCE$EDTMENTS
GENERAL STATEMENT
An outgrowth of this investigation is the overall recognition of
four different time packages of sediments that contain uranium occurrences
(Figure 36). The youngest, the late Cenozoic basin fill, is believed to
be younger than 13 to 10m.y. in age, depending upon locality. Although
this sedimentary group is the object of important uranium exploration,
it is not discussed in this report. For a summary of these materials
see Peirce, 1976; Eberly and Stanley, 1978; and Scarborough and Peirce,
1978. However, it should be pointed out that we are limiting the Basin
and Range disturbance to the block faulting event that produced the depo-
centers exploited by the late Cenozoic basin fill deposits. This event,
and subsequent sedimentation, in places tectonically disrupt and cover
the three older uranium-bearing sedimentary sequences.
The three older age group assignments are:
(1) Oligocene sediments interbedded with variable amounts of
volcanics, but_ mostly pre~volcanic in the southeastern
part of the state. Includes the Mineta and Pantano forma~
tions.
(2) Early Miocene sediments in the central and west central part
of the state contemporaneous with much silicic volcanism.
Includes the Anderson area host rocks.
(3) Middle Miocene sediments and volcanics in the central part of
the state. Includes the Lake Pleasant
deposits.
. -,7-
and Horseshoe dam
For this report Cenozoic epochal boundaries are taken as:
Oligocene 38-22 m.y., Miocene 22-6 m.y., Pliocene 6-1.8 m.y. It is
useful to further subdivide the Miocene: early 22-16 m.y., middle
16-11 m.y., late 11-6 m.y.
Some generalized structural and stratigraphic relations of Tertiary
volcanics and sediments in the Basin and Range Province are illustrated
in Figure 1, a cross-section from the Sierrita Mountains through Tucson,
the Rincon Mountains, the San Pedro Valley, the Galiuro Mountains and
ending in the Winchester Mountains. The Basin and Range faults are those
which lie more or less symmetrically disposed about present valley axes
and form the boundaries of the mountain and basin blocks. However, it is
easily noticed that the present valleys are now almost always larger than
the basin blocks because of pediment backwearingof i:the mountain Thlock
edges. This Basin and Range "process" has had the net effect of deform
ing and plastering older Cenozoic materials against the older still rocks
of the mountains. Thus, units such as the Mineta Fm. (figure 1) are found
at the edge of, but commonly in tectonic contact with, the materials of the
mountain blocks. More rarely, the older Cenozoic materials are found in
the valleys where recent dissection has exposed pedimented terrains con
taining these rocks, as in the San Pedro Valley (Figure 1).
Following is a brief geologic summation of the areas and localities
identified for this report as containing pre-basin fill Cenozoic sedimen
tary rocks. Not all contain known anomalous radioactivity. Table 1 is a
list of 41 localities having known anomalous radioactivity, 36 of which
are largely sedimentary and five of which involve other host rock types.
Of these 41 occurrences, 25 were visited.
-8-
The order of presentation is from the oldest to the youngest of the
three chronological groupings. Where appropriate the number of PRR's
associated with either a formation or topic area is shown as is the
reference number to Table 1 and Figure B, which list and locate localities
with radioactive anomalies.
GRPUKJ" LOCALITIES WITH RADIOACTIVE ANOMALIES
Mineta Formation(3PRR's-Nos. 26-28)
The Mineta Fm. crops out on the eastern flank of the Rincon Mountains
Figures 1 and 2). It was named and mapped by Chew (1952) and mapped by
Clay (1970). Bissett, 1958, Granger and Raup, 1962, and Thorman and
Drewes, 1978, have discussed uranium occurrences in the Mineta Fm. It is
a 2-3000 ft. thick deformed nonmarine section, dipping ENE at 30-700, con-
sisting of a basal conglomerate overlain by a red and yellow colored
sha1e-mudstone-1imestone sequence which becomes gypsiferous and white
colored at the top. The Formation is in both high angle fault contact
with older rocks of the Rincon Mountain block, and locally depositional
on granite. The entire formation is unconformably overlain by a 27 m.y.
old basaltic andesite (Shafiqu11ah and others, 1978) and hence is con-
sidered to be Oligocene or older in age. The sediments are in high angle
fault contact to the east with late Cenozoic basin fill materials. A
rhyolite which outcrops discontinuously at or near the base of the forma-
tion yields a 25 m.y. K/Ar age (this study-Table Z), which overlaps
analytical error limits of the over1ying i basa1tic andesite. Hence if the
K/Ar dates are to be trusted, deposition of at least 2000-3000 feet of
Mineta formation and 400 of eastward homoc1ina1 tilting took place in a
very short time.
"":9-
Two PRR localities were visited. Radioactive zones (lOOx) of
light and dark gray mudstones occur as discontinuous lenses up to 10 feet
thick in the basal conglomerate, some of which are very near the basal
depositional contact. The granites beneath the contact also contain
anomalous radioactivity. One to two hundred (100-200) feet higher in
the sequence, radioactivity (to 5x) is associated with slightly fetid
limestones and varicolored shale beds (to 100 feet thick). In general,
the anomalous zone extends for at least 5 miles along strike but individ-
ual anomalous areas are discontinuous at the surface. The section is
essentially devoid of intercalated volcanics except for a welded rhyolite
tuff bed whi6h outcrops discontinuously at or very near the base of the
section for several miles (Clay, 1970).
Cardinal Avenue Sediments(lPRR-No. 30)
This occurrena8 mapped by Brown (1939), Wilson and others, (1960),
and studied by Grimm (1978), is an isolated outcrop of Tertiary low energy
nonmarine sediments which is in the southeast corner of the Tucson Moun.,..
tain structural block and is exposed as part of a stripped pediment
(Figure 1). The limestone outcrop covers less than one square mile and is
in fault contact to the west with Cretaceous andesites, and covered to the
south and east by coluvium. The contact with older Cretaceous volcanics
to the northeast has been interpreted as depositional (Grimm, 1978) but
the contact is very poorly exposed. The sediments consist of a mixture of
well-bedded strongly fetid limey strata with 1-2 ft. thick beds, with
lesser amounts of gypsiferous mudstones and gypsum beds, folded into a
symmetrical shallow syncline, the axis of which occupies a knoll ~
at the present time owing to the resistance of the limestones to weather-
ing. No more than 20 feet of section is now visible. The contained
hydrocarbons are believed to have been derived from plants. Anomalous
radioactivity (to 5x) and carnotite fracture coatings are found in various
spots in the limestone beds. Silicification is not noted at this locality.
These beds are difficult to place in time because of the limited amount of
section visible. The unit can perhaps be best placed within the Oligocene
along with the Pantano and Mineta Formations because they all contain sim-
ilar lithologies. They may represent a once continuous low energy depos-
itional domain.
Teran Basin Sequence(No PRR-No. 41)
The Teran Basin sequence along the southwestern flank of the Galiuro
Mountains is not described in the literature, but was visited during this
study (Figures 1 and 3 for general stratigraphy). The sequence is basi-
cally a homoclinally eastward dipping high and low energy clastic section
whose major lithologies include a lower fanglomerate, a thick mudstone-
shale-sandstone section, and apparently an upper thick fanglomerate
section. An andesite concordant above the middle fine-grained clastics
has a 27 m.y K/Ar date (this study-Table 2). The entire sequence is judged
to be Oligocene based on late Oligocene K/Ar ages on Galiuro volcanic
flows which unconformably overlie the section (Creasey and Krieger, 1978).
The section is here judged to be correlative with the Mineta and Pantano
Formations based upon general structural setting and lithologies .
. Radioactive anomalies of- 2x and 3x:were-noted in-two different mottled
yellow and_brown gypsiferous mudstone units .in the fine-grained clastics.
Anomalous limestone beds that had been rumored to be in the area were not
located. Anomalies were very localized, and attempts to develop them
along strike failed. Those detected were apparently confined to particu-
lar beds and were not notably structurally controlled.
Swisshelm Valley(No PRR-No. 40)
This region was mapped by Cooper (1959). Figure 7 summarizes the
general geologic setting. The valley that lies between the Swisshelm
Mountains and the Pedregosa Mountains in southeast Cochise County is here
called the Swisshelm Valley. The southwest-flowing Mesa Draw has recently
incised its way through basin fill, and a pedimented terrain containing
presumed Oligocene rhyolites, tuffs, and pyroclastic bedded deposits has
been exposed in an east-west arcuate swath across the valley in the general
area of the Bar Boot Ranch, sec 36, T20S, R28E. The pedimented rocks can
be seen in channel bottoms in much of this area where they may only be
covered by thin, Pleistocene gravel caps. The structure of the area was
not investigated except that a high angle basin and range fault was seen
separating the eastern Swisshelms from the low relief pedimented terrain
in west 1/2 sec 29, T20S, R28E.
The sandine-bearing rhyolite vent complex south of the Bar Boot ranch
house counts to 240-300 cps, which is a high count rate for rhyolites.
(Similar anomalous rhyolites of the Chiricahua sequence in west Turkey
Creek of the Chiricahua Mountains 15 miles north, count to 400 cps).
A complexly deformed section of tuffs and tuffaceous sediments north
and west of the Bar Boot Ranch count to 200-250 cps which normally
would be a value of 2x. Whether or not any anomalous uranium exists in
-12~
these sediments depends upon the source of the high count rate not only
in these sediments but also in the rhyolites nearby.
Adair Park Redbeds(No PRR-No.' 35)' -
This is an unnamed stratal sequence just north of Yuma in extreme
western Arizona. These rocks were mapped by Olmstead and others, (197~'3)
and are depicted in Figure 4. This is a rather thick sequence of steeply
SW-dipping redbeds which is exposed in the Southern Laguna Mountains.
Assuming the section is not overturned, it appears DO represent a generally
coarsening upward clastic sequence with lowermost sandstones and partially
gypsiferous mudstones, middle fanglomerates and high energy fluvial red-
beds with minor lacustrine limestones or calcic soil horizons, and an
upper very coarse boulder conglomerate or debris flow deposit. This se~
quence is apparently unconformably overlain by the nearly flat-lying Kinter
Formation, which, in this immediate area, contains a dated 23 m.y. old
bentonitic ash bed. Nearby silicic volcanic flows, tilted in a similar
fashion as the Adair Park beds, yield 26 and 29 m.y. ages (all age dates
reported in Olmstead and others, 1973). Along the north and east boundary
of the redbed outcrops, is a high angle fault contact with a gneissic
granite terrain shown as Mesozoic in age on the 1969 Arizona State geo~
logic map (scale 1:500,000).
Anomalous radiation (to 3x) was noted within the lower part of the
package in some orange and yellow mottled gypsiferous mudstones within 20
feet of the fault contact. The radioactive zone was confined to a 10 foot
or so thick interval, but the nearby fault zone itself was not noted to be
anomalous. The remainder of the redbeds, particularly the higher energy
units, apparently are devoid of anomalous radiation.
· -13...;.
East Side of Plomosa Mountains(2PRR's-Nos. 7-8)
A brief survey was conducted and the general geologic relationships
are shown in Figure 5. A SSE dipping Tertiary section is exposed in a
dissected pediment area on the east side of the Plomosa Mountains. It is
in tectonic contact to the west with, and possibly overridden by, Mesozoic
(?) metasediments which in the general area have very similar structural
attitudes as the Tertiary section (Jemmett, 1966). Owing to almost certain
structural complexities, the Tertiary -strafaJ sequ~ncecann'ot be described
with confidence. Noted were abundant silicic to intermediate volcanic
flows with associated lenses of intercalated low energy clastics including
buff colored mudstones, 1-3 ft. beds of medium gray limestones, and a few
red brown fluvial conglomerates containing clasts of Mesozoic metasedi-
ments. The limestones are somewhat fetid and attain local thicknesses of
up to 100-150 ft. Eberly and Stanley (1978) report a 24 m.y. age date on
a silicic flow that apparently is high in the section.
P~dioactivity was noted in three areas. The first is that reported
in the PRR report on the Rayvern Claim Gp, namely, a 3 ft. thick white
calcareous mudstone layer (9x) with visible carnotite fracture coatings
sandwiched in the middle of the 100-150 ft. thick gray limestone section
noted above, down which a shaft has been dug. The second occurrence is
farther north by 1.0 mile and consists of a minenl.lized NW treridingv.erti-
cal fault that cuts, a dark red-brown ; fluvialcong1.ome.rilte::-iilolJg
which rather new dozer cuts have been placed. Radioactivity (to 90x)
is clearly confined to red clay-rich fault gouge. Nearby surface out-
crops of the conglomerate are anomalous (to 5x) but nearby sub"",parallel
"';'-14-
faults are not anomalous. The third occurrence is 0.25 miles farther
north and is confined to anomalies (to 4x) in a 4 ft. thick chert nodule-
rich light gray limestone bed that, along with a 20-50 ft. thick light
colored mudstone layer, is sandwiched into a volcanic-pyroclastic part
of the section.
Muggins Mountains(7PRR's-Nos. 10-16;Access problems-not visited)
Existing PRR's and reports indicate anomalous radioactivity and uranium
occurrences in at least six different sites in the Southern Muggins
Mountains. These occur within a SW-dipping Tertiary section and several
appear to lie along strike and hence may be sampling an anomalous zone or
trend in the Tertiary section. Mineralization appears to be confined to
fine-grained clastic and limestone beds in most areas, but, in one, it
seems to be related to the margins of a near-vertical dike of dark
volcanic rock. Judging from the amount· of interest and the number of
PRR's located in the vicinity, further recon studies are warranted.
(Access problems are governmental). A 22 m.y. K/Ar age has been determined
on a tuff bed which is probably intercalated into this general strati-
graphic section (Damon and others, 1968).\
This dated horizon is 400 ft.
stratigraphically below a vertebrate fossil locality of Late Arikareean
(?) age (24-21 m.y. from Tedford 1974 Land Mammal age compilation) re-
ported by Lance and Wood (1958). They suggest the presence here of a
4000 ft. thick stiatal section with dips of up to 600 • The fossil site and
the K/Ar dated horizon is in the upper one fourth of the section. An
. Oligocene age assignment appears reasonable.
-15,...
Western Gila Bend Mountains(lPRR-No. 25)
This is the area of the Duke, \-Thite and Hyder uranium claims. ~'The
general geology is indicated in Figure 6.
The region contains at least two en echelon,tilted, downthrown
fault blocks that contain pedimented Tertiary clastic sequences. The
sections dip 15-300 NNE, and consist basically of calcareous, fairly well
sorted, arkosic sandstones with many thin individual beds (0.5-1 ft. thick)
of dark gray fetid laminated limestone. Mudstones and shales are not
common in the westernmost block, but comprise greater than 20% of the
section in the eastern fault block. Both sections contain a single inter-
bedded biotite-bearing silicic volcanic flow dated at 23.7 m.y. (This
study-Table 2). An exploration well drilled in the western block pene-
trated 270 ft. of sediments before intercepting crystalline basement.
An entirely younger clastic and tuffaceous sequence underlies Yellow
Medicine Butte, whose capping basalts have not been dated in this area,
but similar mesa forming flows farther to the east produce 22-16 m.y.
K/Ar ages (Miller and others, 1977). Because these suspected early
Miocene volcanics dip 5-100 in this region, and the Tertiary sediments
in question dip 20_400, the sedimentary section is believed to be Oligo-
cene in age because it is apparently involved in an older tilting episode
that does not affect the early Miocene rocks. These older sedimentary
rocks are shown as Cretaceous-Tertiary on existing County and State
geologic maps.
Radioactivity in the area is confined to a few thin fetid dark gray
colored limestone beds in the western block (to 3x) and is interestingly
-16 -
absent from the mudstones of the eastern block. The arkosic sandstones
do not count above general background. The radioactivity of the limestone
beds does not continue far along strike.
GROUP I LOCALITIES WITHQUT KNOWN RADIOACTIVE ANOMALIES
Several areas in southeast Arizona are recognized as containing
thick clastic sequences of deformed Oligocene sediments, sediments not
known to be anomalously radioactive.
Pantano Formation(lPRR,....No. 29)
The Pantano Formation was named by Brennan (1958) and has been mapped
and discussed, in part, by Finnell (1970; 1971) and Drewes (1978). It
consists of a 6000 ft. or thicker homoclinally dipping sequence of clas~
tics which, according to Finnell, consists of a basal mudflow sequence,
overlain in turn by a thin somewhat fetid limestone unit, a fanglomerate
unit with minor mudstones, an andesite unit variously thin and thick, and
a locally thick relatively pure claystone unit containing gypsum seams and
monolithologic "megabreccia" clasts and beds. Several age dates have been
obtained on intercalated volcanics that indicate that the Pantano Forma~
tion is Oligocene in age (Finnell, 1970). One PRR locality (the Red
Hills claims) near Colossal Cave, Rincon Mountains is in a structurally
complex terrain where some Pantano (?) fine,....grained redbeds are faulted
against Rincon Valley granodiorite. However, these sediments may just as
well be related to the Miocene Rillito beds of Pashley (1966). Radio~
activity (to 2x) was noted in some varicolored sandstones and mudstones
at one spot, and in the Precambrian Granite (to 5x) near some of the
high angle faults at another nearby locality. (Subsequently, we've been
told that some of the thin, fetid limestones count to 4x).
-17-
Helmet Fanglomerate(No PRR-Not visited)
The Helmet Fanglomerate of Cooper (1960) in the eastern Sierrita
Mountains is a poorly exposed 10,000 ft. thick sequence of high energy
clastics composed of fanglomerate mudflows with intercalated monolitho-
logic megabreccia beds and volcanic flows which have K/Ar dates which
place the sequence into Oligocene time. The sequence is notable in that
the entire section and juxtaposed older rocks is demonstrably allochthon-
ous, being separated from lower plate rocks by the low angle, shallow
eastward dipping "San Xavier thrust fault" (Jansen, 1978; Shafiqu.ll.ah_
and Langlois, 1978) (Figure 1).
Threelinks Conglomerate(No PRR)
The Threelinks Conglomerate of Cooper and Silver (1964) is a pre-
volcanic high energy mudflow sequence with minor intercalated limey mud-
stone beds and undated volcanic flows. It is highly contorted and
beveled beneath late Oligocene volcanics of the Galiuro Mountains. It
was visited only in the Winchester Mountains (Figure 1), and not in the
Steele Hills further south.
Whitetail Conglomerate(No PRR~Not visited)
The Whitetail Conglomerate (Peterson, 1969) is a unit of variable
thickness largely because of a high-relief lower contact. It frequently
is faulted and tilted and consists mostly of light to moderate colored
high energy fanglomerates and minor low energy tuffaceous heds. It con-
tains a 32 m.y. old K/Ar dated ash bed intercalated high in the section
in the Sonora Quadrange (Cornwall and others, 1971), and a 33.5 m. y. old
-18 ...
K/Ar dated ash bed at Aravaipa Creek in the Ga1iuro Mountains (Krieger
and others, 1979).
Redbeds of Babocomari Ranch(No PRR-Not visited)
These redbeds are exposed in the northern Huachuca Mountains and
have been described by Vice (1970). They consist of arkosic gravels and
tuffaceous sediments tilted westward and are overlain by a thrust plate
of Paleozoic limestones. They apparently contain, according to Vice,
late Oligocene K/Ar dated volcanic flows.
Redbeds at Three Buttes(No PRR-Not visited)
These redbeds, discussed by Banks and others (1977) are a northeast-
dipping section of fluvial sediments in the northern Tortolita Mountains,
and is composed predominantly of sandstones with a minor component of
fine-grained beds. The section contains a basalt flow dated at 21 m.y.
and hence likely is Oligocene-Miocene in age (Jennison, 1976).
Hackberry Formation(No PRR-Not visited)
The Hackberry Formation near Hayden of Schmidt (1971) is a 10,000 ft.
thick section of clastics which contains diversified coarse and fine-
grained units including massive 'megabreccia" lenses (Krieger, 1977). It
is folded and unconformably overlain by less deformed Miocene fang1omer_
ates. Ages of 20.5, 23.5, and 25.6 m.y. on biotite, hornblende, and
plagioclase, respectively, were obtained from an air-fall ash bed inter-
ca1ated into a "granite-wash" facies of the unit (Table 2). In this
vicinity, the Hackberry Fm. and the Paleozoic and Cretaceous section upon
which it is depositional are folded into an assymetric syncline whose
west limb is overturned.
-19'-
Apsey Conglomerate(No PRR-Not visited)
The Apsey conglomerate of the northern Ga1iuro Mountains around
Aravaipa Creek is a blanket of light colored high energy fang10merates
which sits atop the volcanic tablelands of the area. The underlying
Ga1iuro volcanics date at 28.2-22.5 m.y. (Creasey and Krieger, 1978),
while an andesite overlying the Apsey conglomerate at Table Mountain
+dates at 22.8 - 0.5 m.y. (Table 2-this report). This age bracketing of
the conglomerate at about 22 m.y. assumes some importance in regional
pre-basin fill correlation schemes (see Heindl, 1958). For example, this
age casts doubt on the correlation of Apsey Conglomerate with the prob-
able late Cenozoic basin fill Hell Hole Conglomerate of Simons (1964),
or the 14-17 m.y. Big Dome Formation of Krieger and others (1974) near
Kearny. All of these units are typically coarse textured.
Locomotive Fanglomerate(No PRR)
The Locomotive Fanglomerate (Gi11u1y, 1946) at Ajo is a thick SW
dipping assemblage of high energy sediments including extensive thick
mudf10w units and coarse fluvial fanglomerate deposits. See Figure 9 for
cross-section.
Si1 Murk Formation(No PRR)
The Si1 Murk Formation of Heindl and Armstrong (1963) crops out near
Gila Bend. See Figure 10 for cross-section. The Formation as mapped
consists of lower, more highly deformed sediments and a less deformed
series of overlying volcanics and sediments. Basal well-sorted red
arkosic sandstones which are locally depositional on Precambrian granite
-20""-
display large scale trough cross-bedding of aeolian origin, and are
500-1000 ft. thick. Overlying red-brown fang10merates are 1000-2000
ft. thick, and contain dominant debris flows and subordinate fluvial
high energy beds. Together, these two lower units dip SW.at 20-600
•
The overlying predominately volcanic section dips SWat 3_100 and con-
tains a welded ash flow sheet high in the section dated at 27 m.y.
(Eberly and Stanley, 1978) along with andesite flows and poorly exposed
high energy fluvial sediments.
Clanton Hills Section(No PRR)
This section is discussed by Wilson (1933) and Ross (1922). See
Figure 8 for cross-section. The section visible in the main watergap
(Sec 12, T2S, R12W) consists of the following ascending sequence: a
dense rhyolite flow dated at 23 m.y. (Eberly and Stanley, 1978), red
arkosic sandstones and mudstones capped by a thin cherty limestone, more
red arkosic sandstone that grades upward into a rhyolitic ash fall, and
then into a rhyolite explosion breccia or high energy flow breccia, than 'a
capping, partially brecciated, black chert nodule limestone bed about
10-15 ft. thick. The entire sequence is probably no thicker than 300 feet,
is highly faulted, but is not generally tilted. However, nearby isolated
hills contain a uniformly SW dipping dark volcanic sequence which dates
at 28 m.y. (Eberly and Stanley, 1978). The Clanton Hills Limestones are
only locally fetid and display anomalies no greater than 1. 5x.
Osborne Wash(No PAA)
Figure 13 shows a cross-section through the area of Osborne Wash,
about 10-20 miles east of Parker. A sequence of high to moderate energy
fluvial redbeds and a Tertiary limestone section dip to 40° and trend
along a large NW-trending antiform, are beveled by pedimentation, and
are overlain in the eastern area (see cross""'section) by undeformed sedi-
ment and basalt series with a basal flow dated at 9.7 m.y. Farther west,
the older sediments are apparently in high angle fault contact with other
blocks of volcanics and sediments which dip 5~10o SW and have two K/Ar age
dates of 16 and 21 m.y. Hence by circumstantial evidence, the older sedi-
ments are likely pre~2l m.y. in age.
The older redbeds and limestones in places are in low angle tectonic
contact with the cataclastically deformed crystalline rocks of the western
Buckskin Mountains. The limestone section is about 1200 ft. thick, dips
30~40o SW, and is the thickest Tertiary limestone sequence observed during
this study. It is present in a separate area from the redbeds, and their
stratigraphic relationship is unknown at this time. Most limestone units
are somewhat recrystallized. Chert nodule horizons are uncommon. Copper-
iron-uranium mineralization at the Pride Mine is confined exclusively to
the lower plate rocks. Radioactive anomalies of 3x are found in "pods"
of limonite rich hydrothermally altered crystalline rocks. Light colored
fluvial channel and overbank sediments (locality 2b in Figure 13) underlie
and are deformed with the l6~2l m.y. old volcanics. They contain no
apparent anomalous radioactivity.
Phoenix Region(No PRR)
Several areas in the south-central part of the state contain high
energy clastic redbed packages which are not known to contain radioactive
anomalies.
-22-
In the Phoenix metropolitan area (Figure 11), southwest dipping red
laminated mudstones are exposed at Tempe Butte where they are overlain
concordantly by a 17 m.y old dark volcanic flow (Table 2-this report).
Peters (1979) suggests that the Tempe Butte beds represent flash flood
deposition on the floodplain of a large fluvial system. Farther north, in
Papago Park, a thick sequence of SW dipping mudflow or debris flow depos
its, in places containing large rounded boulders of Precambrian granite,
are seen to grade downward into the fine-grained Tempe B~tte beds. These
coarse redbeds are intruded by a series of N250 W trending rhyolite dikes
which form some of the rock spires of Papago Park. Farther north, at the
west end of Camelback Mountain (total distance from Tempe Butte about
seven miles), thick mudflow sequences underlain by red colored laminar
bedded granite-derived grus deposits of probable moderate energy piedmont
fan origin, are clearly depositional to the east upon Precambrian crys
talline rocks. Cordy (1978), who mapped the Camelback Mountain area, has
divided the 600 ft. thick Tertiary sedimentary section, which she calls
the Camels Head Formation, into four members. The Echo Canyon Member con
tains considerable evidence of massive landsliding which she likens to
some "megabreccia lenses" described in the San Manuel Formation by
Krieger (1977). Some of the landslide deposits contain "metarhyolite"
clasts which resemble some of the rhyolite dike material of Papago Park
mentioned above. She cites earlier workers who correlate some of the
Camels Head Pm. sediments with redbeds at Papago Park and Mt. McDowell to
the east, based upon lithologic similarities.
A 5400 ft. deep hole (Biery-State #1) was drilled in northern Para
dise Valley in 1951. Beneath 4900 feet of fine to coarse-grained clastics
-23-
occur, in descending order, 80 feet of impure gray limestone with abundant
gray and brown chert (see under Miocene sediments), 320 feet of dark vol~
canics, and 500 feet of redbeds to the bottom of the hole. Eberly and
Stanley (1978) K/Ar dated a "oasaltic andesite" from the volcanic section
+at 22 - 1.2 m.y. (#62). Peirce (oral communication, 1979) provisionally
correlates the redbeds under these volcanics in the drillhole with the I[
outcropping redoeds of the Phoenix area. Hence, some, if not all, of the
above outcropping redbeds are likely to oe Oligocene in age.
Along the lower Salt River, 24 miles east of downtown Phoenix, is ex~
posed a section of gently westward dipping high energy redoeds with inter~
.bedded volcanic flows, which are depositional upon a stack of andesite
flows (Figure 12). To the southeast, this section is in high angle fault
contact with a sequence of tuffs and pyroclastic units, while to the north
the andesites are in high angle fault contact with Precambrian granite.
However, the redbeds appear to oe depositional upon both the andesite and
the Precambrian granite. The redoeds here are a mixture of 2/3 mudflows
and 1/3 fluvial beds. Their age is uncertain. None of the other redbed
localities previously discussed contain andesite flows beneath the red~
beds except at Osborne Wash where the redoed package is circumstantially
pre~2l m.y. in age. Andesite oeneathredbeds at the Hassayampa locality
near Wickenburg date at 16.s"ml'Y. (Taole 2) and demonstrate the presence of
likely middle Miocene redbeds at that locality. Thick redoeds of the Sil
Murk 'Formation are p:t'e~26 m.y •. in age. At the edge of the Town of Casa
Grande, a lone hill upon which the community has built a water tank, is
composed exclusively of high energy redbeds which are mostly mudflow units
with very thin fluvial sand lenses. These are tentatively correlated
with the Oligocene redbeds of the Phoenix area.
:GROUP IJ LOCALITIES WITH RADIOACTIVE ANOMALIES
Black Butte(4PRRts-Nos. 19..-21- - see below)
Black Butte is located in the westernmost Vulture Mountains (Hewett,
1925; Kam, 1964). See cross-section Figure 14. The Black Butte section
can be most easily interpreted as a SW..-dipping sequence of andesites with
a basal thin arkosic conglomerate that is depositional (12 on a leuco-
granite and overlain by a fine..-grained mudstone....air fall ash sequence that
is unconformably (?) capped by a volcanic flow K/Ar dated at 15 m.y.
(Table 2...this study). The lower andesite volcanic flow (see Figure 14)
dates at 20 m.y (this study) and hence the fine..-grained uraniferous hori....
zons are indicated to be 20-15 m.y. in age. In one bulldozer trench cut
into a 30....50 ft. thick, light colored mudstone'I""Vitric ash sequence, some
carnotite was noted as fracture coatings. Low radioactivity (Lx) indi~
cates the possibility of uranium disequilibrium. No attempt was made to
visit each PRR. On-ly three of ~the four, because of location problems ,are
shown on Figure B. Farther southeast by two miles or so, other more
diversified low energy sediments are seen to occupy a roughly equivalent
stratigraphic position as the mudstones. This section includes mudstones
containing a ripple marked tuff bed, somewhat fetid limestone beds, one
of which is brecciated and contains chert replacements, veinlets, massive
pods, and veins. Slope.....forming units appear to consist of tuffaceous and
pyroclastic units. Radioacti'Vity here was no greater than 2x, and no
visible uranium mineralization was noted.
~25~
New River(lPRR-No. 23)
The New River area is the western part of a larger region that repre~
sents the interface between the Transition Zone to the north and the Basin
and Range Province to the south (Figure 1b). A significant part of this
general area contains terrain consisting of a complex assemblage of basalt
flows, tuff and pyroclastic beds, and mudstones, overlain by mesa~capping
basalts. Thick basalt caps (14-15 m.y Hickey~aged basalts, this report)
protect the tuffaceous assemblage on New River Mesa, but the assemblage
has been downthrown to the south along high angle east~west normal faults,
and pedimented and mostly covered by thin deposits of young gravels in the
valleys of the general area.
A PRR locality (No. 23 ~ Table 1) about nine miles WNW of Cave Creek
is an important occurrence at the junction of the two provinces. The Los
Cuatros claim group is in the pedimented, low relief zone. It consists
of a somewhat faulted and folded sequence of outcropping 1edgy dolomites
about two feet thick~ interbedded with calcareous mudstones, a thin vitric
air fall ash bed, and zeo1itized units. Recent exploration indicates that
the do1omite~bearing sequence is underlain by mudstones. The Los Cuatros
sediments are about 200-300 feet thick and overlie dark-colored volcanics.
To the west these beds are cut by a high angle fault. At the surface,
radioactivity (to lOx) is confined to the thin ledge-forming nonsi1icified
dolomite beds. No visible uranium minerals are present. Chemical ana1y-
ses conducted by private parties confirm the presence of uranium in these
radioactive beds up to about .07% U308 , Exploration drilling is in pro-
gress in the area and more should be expected in the near future.
Two age dates were obtained during this study that relate to the age
of these sediments. A basalt flow at a!nearby peak (Pyramid Peak),
thought to be below the section, dates at 17.7 m.y. (Table 2). A basalt,
interpreted to be a dike intruding the mineralized sediments, dates at 13
m.y. (Table 2). According to the scheme used here the sediments are
classed as being early Miocene in age.
Cave Creek(No PRR-No. 42)
About three miles NNE of the community of Cave Creek, exposed along
the banks of Willow Springs Wash in a growing residential area, is a
poorly exposed section believed analogous to that just described several
miles to the west. The exposed beds are a SW-dipping, white colored
tuffaceous assemblage containing a thin vitric ash bed, marls and thin
limestones with chert stringers and vein1ets, and tuffaceous marly beds.
Notably, the assemblage here contains but sparse dolomitic zones and much
chert. Radioactivity in certain very confined zones in some limestone
beds measures 5-8x and chert frequently is radioactive. No visible uran-
ium minerals were noted. These beds, by reasons of analogy, are believed
to be lower Miocene in age.
Rifle Range Section(No PRR,....No. 43)
The Rifle Range section is a relatively small northeast tilted basalt
capped range block that forms a cuesta near the junction of I~17 and Care-
free Highway (Figure 17). There are poorly exposed tilted sediments be-
neath the capping basalt. However, one south-facing wash, on the rifle
range side, exposes about 150-200 feet of section.. The arrangement of
lithologies is analogous to that at New River (No. 23) in that a
carbonate~bearing section overlies a lower, relatively thick clastic
zone. There are two dolomitic units each about 20 ft, thick. The lower
dolomitic unit is brecciated and contains extensive chert replacements
and stringers. The upper unit also contains some chert stringers and re~
placements. Anomalous radioactivity (to 3x) is associated with the cherty
portions of the dolomites. The basalt cap appears to overlie the dolo-
mites with a slight angular unconformity, and has a K/Ar age of 15.9 m.y.
(this project~Table 2). The New River locality is about eight miles to
the northeast. By a combination of analogy with New River and the 15.9
m.y. minimum date, we assign a lower Miocene age to this sedimentary se-
quence. Contrasts with New River include some conglomeratic materials
in the lower clastic section and much chert at the Rifle Range locality.
Artillery Formation(5PRR's-Nos. 2-6;3PRR'snot visited)
The Artillery Formation was named, mapped and discussed by Lasky and
Webber (1949). More recently Otton (1977, 1978) discussed preliminary
results of his continuing regional studies. The general geologic settings
of the two localities visited are shown in Figures 18 and 19. The forma-
tion ranges up to at least 2500 feet in thickness.
Two localities in the type Artillery Formation as defined by Lasky
and Webber were visited, the Masterson Claims and the Lucky Four Claims.
The Masterson Claims are west from Artillery Peak, and are contained in
the lower part of the westward dipping Artillery Formation (Figure 18).
Uranium mineralization is found in laminated mudstone-shale-limestone beds
just above a basal 150 ft. thick red arkosic conglomerate believed to be
depositional on porphyritic granite. The low energy clastics contain
many bright colors, and radioactivity is found in many individual units
especially in a bright green colored shale-mudstone sequence (to 5x),
but the most pronounced anomaly (16x) was found in a somewhat cherty,
dark colored, thinly bedded limestone unit about three ft. thick. Much
recent dozer activity and drilling in the area is evident.
The Lucky Four claim group is located south of Artillery Peak in a
thick sequence of limestones and marlstones with minor mudstones 2000 ft.
or more above the base of the Artillery Formation (Figure 14). Here the
section dips generally southward away from Artillery Peak. Much recent
drilling and dozer activity has been centered in these limestones. The
PRR discusses a black carbonaceous layer that was not relocated in this
study, but several wavy-bedded, yellow colored limestones up section from
the black layer, count to 5x at the surface. This material, at depth, is
probably the target for the drilling. The limestones are overlain by a
section of poorly exposed red mudstones. Further south the Artillery beds
either underlie some basalt-capped mesas or are in fault contact with
younger volcanics at the base of the mesa cliffs.
The geology of the Artillery Peak region is complicated by complex
tectonism involving allochthonous stratigraphic sequences. This fact has
tended to obscure the age of the Artillery Formation.. Between the Master
son claim group low in the Artillery Formation and the Lucky Four group
high in the formation there is a densely welded rhyolite flow that out
crops discontinuously along strike. This rock is dated at 19.9 m.y.
(this study.,-Table 2). Some will question the validity of this date on
the basis that it is a whole rock determination on silicic material and
such material is often thought to incompletely retain radiogenic argon.
-29-
However, the material appears densely welded and shows no signs of
deuteric alteration. Still younger rhyolite volcanism is noted from 20
miles or so west where Suneson and Lucchitta (1979) have recently reported
15~1~10.J m.y. KjAr ages on sanidine and biotite separates from silicic
flows, dikes, and domes, thus providing a precedent for middle to late
Miocene silicic volcanism in the region.
On the assumption that this date is reliable the Artillery Formation
will be considered lower (?) Miocene in age. The Anderson Mine is about
18 miles east of Artillery Peak. The host rocks, low energy carbonaceous
andtuffaceo,us sediments; also are" thought to be lower Mioceue in age.
This is based upon a minimum age of 13.2 m.y. obtained on a stratigraphi-
cally higher basalt flow (this study-Table 2) and a paleontological age
of 21-17 m.y. (Hemingfordian) for a rhinoceros and a camel (Lindsay and
Tessman, 1974). Also, Otton (oral communication, 1979) considers the
underlying volcanics to be late Oligocene in age. These data suggest that
the Artillery Formation and the Anderson Mine area host rocks may chrono-
logically overlap.
Wickenburg Area(lPRR-No. 24)
Uranium occurs in rhyolitic volcanic rocks that were extruded onto a
Precambrian granitic terrain (Table I-Figure B). Uranium as visible tor-
bernite and some invisible mineralization is found in various areas in the
extrusive complex (to 25x), and concentrated to 8x-10x along shear zones
and high angle fault surfaces. No basal arkosic conglomerate was seen in
the section, as had been suggested in the PRR report. The rhyolites are
undated, but probably relate to the early Miocene rhyolitic volcanics of
the Vulture Mountains 12 miles to the west.
":'30;.:..
Lincoln Ranch Beds(No PRR-No. 9)
A section of moderately deformed fluvial-lacustrine-tuffaceous strata,
la.rgely redheds, is located in the Lincoln Ranch Basin just south of the
Bill Williams River. The exposed partial section is estimated to be 1400
feet thick by Gassaway (1972). At the northeastern boundary these rocks
are in the footwall of the NW-trending Lincoln Ranch reverse fault (Wilson,
1962, p. 76), with crystalline rocks of the Buckskin Mountains in the hang-
ing walL To the southeast the section is in low-angle '.tectoniocontactL :with
cataclastically deformed Buckskin Mountain crystalline rocks. Near this
contact the redbeds contain manganese oxide mineralization. Farther north-
ward thin, very light colored tilted beds in the section count 2-3x in a
very limited interval. According to Otton (1978), the Lincoln Ranch sec-
tion contains lacustrine units that intertongue with the coarser Mh-rich
strata, the lacustrine rocks containing some uranium in fractures and as
uraniferous silica in bedded chert. Gassaway (oral communication, 1979)
reports finding Miocene vertebrate tracks in the Lincoln Ranch beds. As
noted by Shackelford (1976) the Lincoln Ranch beds are allochthonous
above a detachment surface, therefore the beds pre-date the detaching
episode. Chronological constraints developed during the present and
previous studies indicate that the detachment phenomenon is regional in
extent and was developed in the interval 16 to 13.,...10 m.y. ago (Figure 29).
With this in mind, plus regional stratigraphic similarities, we place
these s'ediments in the lower half of the Miocene, tentatively the early
Miocene.
....31_
GROUP ,11---- LOCALITIES WITHOUT KNOWN ANOMALIES
Harcuvar Mountains-Bullard Peak
The general geologic setting of these two localities is shown on
Figures 20 and 21 and the positions of these sections is shown on Figure
A. In both localities the stratigraphic section is tilted towards the
southwest.
Along the southeast "arm" of the Harcuvars, a section (Figure 20)
of SW-dipping silicic trachytic flows and pyroclastics with a thin basal
red arkosic conglomerate is depositional upon a granite. A flow in the
middle of this section K/Ar dates at 17 m.y. (this report-Table 2).
Farther west near Bullard Peak, a steeply SW-dipping section (Figure 21)
is in probable low angle tectonic contact with the cataclastically deform
ed rocks of the southern Harcuvars. The section consists (barring
structural complications) of a few thin lowermost silicic flows and pyro
clastic units, an unstratified cobble and boulder conglomerate, a 3000 ft.
thick sequence of andesite flows and flow breccias that grade upward into
lahar deposits with some poorly exposed fine-grained redbeds. An andesite
flow from the thick sequence has a K/Ar age of 15.8 m.y. (this report
Table 2). The Bullard Peak section appears to be on the order of 8500
ft. thick. Neither of these sections contains detected radioactive ano
malies.
The Bullard Peak section is allochthonous above a dislocation or
detachment surface. The lower plate consists of brecciated, cataclasti
cally deformed plutonic crystalline rocks. The 15.8 m.y. date within the
deformed upper plate Bullard Peak section suggests not only that the rocks
involved, both volcanic and sedimentary, accumulated during the lower half
of the Miocene (likely lower Miocene), but that the dislocating event
took place less than 15 m.y ago. Subsequent to this event the region
was arched, the various arches forming the present transverse ranges.
Indications are that these tectonic events post-date both the Artillery
Formation and the Anderson Mine host rocks. Therefore, any attempt at
paleogeographic reconstruction during lower Miocene time must remove the
foliation arches (Rehrig and Reynolds, 1977), and restore the affected
Miocene rocks to their original accumulation site. Davis and others,
(1977) suggest that northeastward directed low-angle transport of analo-
gous upper plate rocks took place in the Buckskin-Rawhide Mountain area
between 15 and 13 m.y. ago. Likely, this event was synchronous with the
positioning of upper plate rocks in the Bullard Peak region of the Har-
cuvar Mountains. In the general area of the type Artillery Formation,
low-angle tectonism emplaced at least one "slide breccia" (Otton, 1978)
either post-2l m.y. (Eberly and Stanley, 1978) or post-15.9 m.y. and pre-
9.6 m.y. ago (Shackelford, 1976). The confusion appears to stem from the
K/Ar age of and/or the selection of the youngest basalt beneath the over-
lying tectonically disturbed zone.
(}ROUPTU.
Horseshoe Dam(No PRR-No. j9)
LOCALITIES WITH RADIOACTIVE ANOMALIES
The general geologic setting of the Horseshoe Dam section along the
Verde River is depected in Figure 22. The section is tilted towards the
southwest, is in fault contact with Precambrian granitic rocks on the
west and flat-lying clastic sediments on the south. The partial section
exposes about 1000 ft. of light-colored tuffs, marls, mudstones, and
-33~
sandstones derived from volcanic rocks. An underlying, tilted ~ndesite
from the dam spillway gives a K/Ar date of 15 m.y. (this report-Table 2).
An indicated mid-Miocene maximum age, and involvement in faulting and
tilting, suggest that this sedimentary sequence should be placed in middle
Miocene Group 3.
Radioactivity was noted in several places in tuff beds (to 3x) and
cross-cutting chalcedonic stringers (to 4x). Minor amounts of carnotite
as fracture coatings were noted. Most of the tuffaceous beds are devitri-
fied, some zeolitized (Eyde_and Irvin, 19:78).
North of Horseshoe Dam by four miles is Chalk Mountain, a relatively
flat-lying remnant assemblage of materials similar to the Horseshoe Dam
sequence. Tuffaceous and marly beds low in the sequence contain visible
carnotite fracture coatings that appear to be local in extent (Tom Howell,
personal communication). Because of high water conditions at Horseshoe
Dam, the Chalk Mountain area was not visited. Also, a similar appearing
remnant assemblage up Lime Creek, a rugged tributary on the west side of
the Verde River, was not visited.
Lake Pleasant Region(No PRR-No •. · 38) .
The general geologic setting 0D the Lake Pleasant region is shown on
Figure 23, It is thought that both groups 2 (early Miocene) and 3 (middle
Miocene) are represented in this region bordering the Transition Zone on
the south.
Wild Burro Mesa, northeast of Lake Pleasant on the Agua Fria River,
consists of a basalt_tuff,..pyroclastic.,-mudstone assemblage very similar to
-34-
the Group 2 assemblage of the New River area to the east. The capping
basalt series is believed to be correlative with
the 15-14 m.y. old basalts
of the region. This entire package overlies an older, more tectonically
deformed andesite-agg1omerate-tuff sequence which yields a 27 m.y. K/Ar
age (this report). Unconformably against the basalt-capped mesa terrain
is a younger (Group 3?) set of white colored, gently folded beds consist
ing of tuffaceous sediments, thin to thick gray to brown cherty limestone
beds and minor mudstones. And younger still are some fine-grained low
energy beds that fill the present basin and probably represent late Ceno
zoic (post-13-10 m.y.) basin fill.
The Lake Pleasant Group 3 strata are relatively widespread and ex
posed by tributaries to the Agua Fria River. Initially, some carnotite
paint on white tuffaceous bedded material was observed in outcrop. Sub
sequently, two exploration programs were conducted by drilling. The base
of the Lake Pleasant lacustrine beds is irregular, the sequence ranging
in thickness from zero to over 1000 feet. Rapid facies change accounts
for a wide variance in the amount of limestone present. Apparently,
drilling failed to reveal unusual amounts of uranium mineralization.
Just west of Lake Pleasant there is an eastward dipping basa1t-tuff~
mudstone terrain that projects beneath the Group 3 deposits (Figure 23).
A dated basalt in this older sequence, likely Group 2, gives a K/Ar date
of 16.6m.y. (this report). A rough correlation with the Wild Burro Mesa
section seems justified.
The gently folded Lake Pleasant Group 3 strata are believed to be no
older than 15 m.y. However, direct data that constrain the minimum age
are not yet known. Tentatively, we have placed them in Group 3 and there-
fore generally correlative with the section at Horseshoe Darn. However,
they could be younger rocks - possibly late Miocene in age.
Big Sandy Valley(lPRR-No. 1)
The Big Sandy Valley is north trending and about 40 miles in length,
bordering the western edge of the Transition Zone. The valley is noted
for its eroded, flat-lying basin fill deposits. However, in places on the
east side deformed pre-basin fill rocks are exposed. Ten to 15 miles
northeast of Wikieup, along Tule Wash, there is an estimated 6500 feet of
NE-dipping section. The section is largely low to moderate energy, light
red to light~colored clastics, with occasional dark volcanic flows, devi-
trified bedded tuffs, and limestones. The sequence is in high angle fault
contact to the east with Precambrian crystalline rocks of the Aquarius
Mountains.
To the south thin remnants of the section are preserved as eastward
dipping downthrown fault blocks. Dip directions of both thin and thick
sections coincide, and the most plausible explanation of the observed
structures is that the sedimentary package has been rotated along westward~
bowing Basin and Range disturbance listric normal faults that served to
define this part of the Big Sandy Valley. Figures 24 and 25 depict some
of these relationships. The original Catherine and Michael uranium claim
is believed to be situated in the easternmost of two small tilted fault
blocks. However, limestones with abundant black chert nodules and
stringers were noted in both of these fault blocks and counts ranged from
2x to l6x in various places in these limestones. In both areas the
~36~
limestones are associated with partially devitrified air fall ash beds,
mudstones and sandstones. The limestones at the easternmost fault block
contain well preserved silicified casts of palm roots (?) in its lower
part.
In another tilted fault block just to the north and west of the PRR
locality, a 500-1000 ft. section is preserved that contains an interca
lated basalt flow that gives a K/Ar date of 12 m.y. (This study-Figure
24). Limestones are included in the section both stratigraphically higher
and lower than this volcanic unit. With no reason to doubt this date, and
in the absence of confirmatory data, we are assigning these deformed rocks
to Group 3. However, they may partially be younger, perhaps late Miocene
in age. Deformation, in turn, is younger than these rocks, which are over
lapped by the undeformed basin fill sequence.
Anomalous radioactivity was noted in two stratigraphic horizons at
Tu1e Wash. The first was in Toreva (slide) block of clay rich gypsiferous
mudstones containing numerous 1/8-1/4 inch thick dark chert stringers
where anomalies of 3x were noted. The other (to sx) was higher in the
section in a white colored wavey bedded laminated limestone bed about 10
15 ft. thick. Farther south, in the farthest west outcrop of Figure 24,
2-sx anomalies were noted in gray medium bedded cherty limestones.
LOCALITIES WITHOUT KNOWN RADIOACTIVE ANO~~IES
Hassayampa River
Just northeast of Wickenburg a NE-dipping section of predominantly
fluvial high energy redbeds unconformably (?) overlies a 500 ft. thick
section of andesites and andesite flow breccias. A sample near the top of
the volcanic section gave a K/Ar date of 16.5 m.y. (this report). This
date, plus the deformation, suggest that the redbeds are middle Miocene
in age (Figure 26).
OTHERS.,... WITHOUT KNOWN RADIOACTIVE AN()MALI~--:
Biery Ifl State
The Biery Ifl Federal is a petroleum exploration test hole drilled in
1951 in Paradise Valley to a depth of 5396 feet (Peirce and Scurlock,
1972). The hole is about 10 miles south of Carefree in Sec. 8, T4N, R4E.
An apparent stratigraphic thickness of about 150 feet occurs in the inter
val 4430-4580. The samples indicate a lacustrine sequence containing
cherty limestones that overlies about 300 feet of basalts. As mentioned
previously, the basalt is underlain by redbeds that we correlate with
similar strata that crop out in the Phoenix region. The basalt gives a
K/Ar date of about 22 m.y. (Eberly and Stanley, 1978).
Although the age of the lacustrine rocks is not known, the data per.,...
mit possible correlation with the Group 2 radioactively anomalous rocks
of the Cave Creek area. If so, these rocks have undergone structural
separation of at least 4500 feet. This could be an example of the pres.,...
ervation of relatively down-faulted older lacustrine strata beneath late
Cenozoic basin fill. There is no record of the existence of a gamma ray
log and the relatively small volume of well cuttings did not noticeably
affect the scintillometer. Chemical tests have not been made. A log of
this hole is available from the American Stratigraphic Company (Catalog
No. D,..330l}.
-38.,...·
CENOZOIC SEDIMENTS ~ STRUCTURE ~ URANIUMFAVORABILITY ~ EXPLORATION
GENERAL STATEMENT
As previously emphasized the focus of this Phase I study is the
chronological ordering of deformed,pre-late Cenozoic sedimentary packages
that contain identified anomalous radioactivity. A result of this attempt
is the preliminary recognition of at least three age groups: (1) Oligo-
cene, (2) early Miocene, and (3) Middle Miocene (this may spillover into
the early late Miocene in areas of youngest Basin and Range disturbance
faulting),
The following paragraphs attempt to provide a general summary of our
Phase I study and to place in perspective some aspects of relatively re~
cent uranium exploration in the Basin and Range Province of Arizona.
PRE~BASIN FILL CENOZOIC SEDIMENTS
Across the Basin and Range Province of Arizona these Oligocene and
Miocene strata have been deformed and are now- seen as tilted remnants on
the structurally high blocks that characterize the Province, Regionally~
each of the three identified sedimentary groups contains two gross litho"'"-
logic packages: (1) redbed clastics, and (2) low energy, light-colored
"lacustrine" clastic and chemical rocks. Thus far, radioactive anomalies
favor the low energy clastics and chemical rocks (carbonates). Frequent-
lY,outcrops tend to be either redbeds or "lacustrine" deposits. Rare
interbedding suggests that these two lithologic types might well be facies
in each of the three groups.
Preliminary correlations strongly suggest that the original e~tent
of the basins of sedimentation associated with each of the three groups
was much larger and generally unrelated to the basins presently charac
teristic of the Province. As an example, the so-called Date Creek Basin
of much past and present exploration interest, is properly a late Cenozoic
structural feature that bears little obvious relationship to the larger
basin in which the Group 2 (lower Miocene) Anderson Mine host and related
rocks likely were originally deposited. Thus, an important question is
the original extent and present buried position of potentially favorable
sedimentary host rocks. Because of their state of deformation, they
should not be expected to be preserved at depth as flat-lying remnants.
In this regard it is important to decipher the number of tectonic events
that may have disrupted and deformed original depositional continuity.
An obvious question is the relationship, if any, between tilting and the
late Cenozoic Basin and Range disturbance. Mounting evidence suggests
that much tilting preceded this last est rifting event. If so, then older
Cenozoic rocks covered by generally flat-lying, thick basin fill, may
well be tilted and thus be a more difficult subsurface, ,target to locate.
Each of these three groups of sediments is more or less associated
with products of volcanism, including flows and air-fall tuffs, many of
which are devitrified. However, interbedded tuffaceous rocks are more
abundant, perhaps ubiquitous, in the two Miocene groups (2 and 3). Sili
cic volcanism seems to have been most important in the lower Miocene
(Group 2), the Vulture Mountains most likely having been a volcanic cen
ter during this time.
Figure 31 is an attempt to depict the "floor" upon which Cenozoic
rocks accumulated. It is clear that this floor is quite variable c
-40-
over the Province. South of the Mogollon Rim there is a large region
that is floored by a diversity of Precambrian crystalline rocks some
of which have relatively high background counts (Malan and Sterling,
1969). Figure 32 shows the distribution of the more alkaline igneous
rocks as presently understood. Some of these are floors while others,
some of the Cenozoic volcanics, are chronologically related to the
various groups.
Figure 30 is a space-time chart of important Tertiary sedimentary
and volvanic units. Also shown is the general distribution of uranium
and/or radioactive anomalies, including some in late Cenozoic basin
fill deposits. The diagram also depicts a younging of subduction re
lated calc-alkaline volcanism towards the northwest.
Figure 33 is a generalized interpretation of transport .direction data.
Phenomena such as imbrication and cross-stratification are preserved only
in the coarser clastic rocks many of which are redbeds. Caution is nee·
essary in interpreting these data because strata of this age are deformed
and many localities are allochthonous. The extent to which any of the
packages may have been rotated relative to compass directions is not known.
It is data such as this that will eventually permit interpretation of re
gional environmental trends. There is a question as to the regional pa
leogeographic habit that prevailed during Tertiary time, especially during
Oligocene-early Miocene time. There is a tendency to view these redbed
"lacustrine" packages as basin edge and basin center deposits. This in
terpretation would be analogous to that produced by the late Cenozoic Ba
sin and Range disturbance where relatively small closed basins are the rule.
However, it is our impression that these various facies could have resulted
from smaller environments within a regional fluvial system of integrated
drainage-they need not necessarily represent "intermontane" deposition.
Cooley (1977) has worked extensively with Cenozoic drainage directions.
In dealing with favorabi1ity the ability of host rocks to produce
a reducing environment during fluid passage seems fundamental in the
western United States. In Arizona, it seems likely that it is this fac
tor that is the most elusive. Uranium sources appears not to be the
priority factor in assessing favorabi1ity criteria. Although the chem
istry of the various Cenozoic strata is not a part of our Phase I study,
generalities are not difficult to identify.
Vegetative debris, in carbonized form, seems to be a preservational
rarity. The one exception thus far, the Anderson Mine early Miocene host
rocks, contain the uranium minera1izationbhat has, in large part, stimu
lated exploration and interest in Arizona's Basin and Range Province Ter
tiary sedimentary rocks. Figure as shows the distribution of State pros
pecting permits in force during 1975-1978. The clustering to the north
west is in the region of the Anderson Mine. If nothing else, the Anderson
subsurface 1ignitic strata demonstrates not only that such materials de
veloped in Arizona but that it is possible to preserve them.
So-called "fetid" strata are not uncommon in the Oligocene "lacustrine",'
sequences. Significantly, many of the radioactive anomalies and known ura
nium occurrences are closely associated with these rocks. One of the most
"fetid" is the Cardinal Ave occurrence (Grimm, 1978), which is a limestone.
One of the more significant and interesting (perhaps unusual) urani
ferous occurrences, presently the obj ect of some exploration, is the New
'-42~ '.'
River (Los Cuatros Group) locality. Aphanitic dolomites (x-ray deter
mination-this study) crop out as resistant ledges that are surprisingly
radioactive. Neither mineralization or contaminating minerals or sub
stances are observable-just very light-colored dolomite. One specimen,
submitted to a company for characterization, contained a small amount
of organic carbon and a U308 content of .031%. Although not obviously
fetid, it seems probable that the uranium content is related to the
small amount of organic matter. The petrogenesis of this dolomite,
though interesting and probably important, is not a part of this present
study, therefore, will not be discussed here. The organic material re
sponsible for "fetidness" is believed to have been vegetable matter.
As has been emphasized, one of the major problems in studying and
exploring rocks belonging to the three general groups defined here is the
absence of continuity. Many of these rocks have been involved in at least
three recognizable tectonic events and perhaps others not yet resolved.
The geologic history of the so-called "metamorphic core complexes" includes
the widespread development of a detachment zone that renders some of these
rocks (perhaps more than are known) allochthonous. This was followed by
regional arching along northeast axes all along the zone of compl~xes
(Figure 28). Subsequently, the Basin and Range disturbance rifted the re-
gion, causing up to thousands of feet of vertical separation between jux
taposed range and basin blocks (Figure 1). The exact nature of this lat
ter disruption is not well understood. It seems important, from an explor
ation point of view, to learn the extent to which half-graben (listric
normal faulting) type deformation may have been involved.
~43.,..
The Anderson Mine host rocks are instructive in many ways: (1)vegetative
early Miocene climates encouraged lush growth, (2) uranium-
bearing fluids were available, (3) early Miocene alkaline volcanism
likely influenced uranium source, (4) the rocks are positioned near
the interface between the tectonically deformed Basin and Range Pro-
vince and the more stable Transition Zone. It is interesting to note
that about 80 miles to the east, from New River to Cave Creek, that
there is a belt of"lacllst.$ilne" strata that are in several ways similar:
(1) early Miocene low energy deposits, (2) contain silicic volcanic tuf-
faceous materials, (3) contain uranium in which small quantities of veg-
etatively derived organic matter may be influential, and (4) are posi-
tioned at the interface between the Basin and Range Province and the
Transition Zone.
This physiographic position, though paleogeographically not under-
stood, provides a measure of continuity not usually available elsewhere
in the Basin and Range Province for strata of this age. These low energy
rocks, as an age group, extend an unknown distance to the south and thus
may occur in the subsurface. Perhaps the Biery State hole in Paradise
Basin is an example.
The positioning of these early Miocene rocks raises questions as to
continuity within the Transition Zone itself. Most likely they are repre~
sented there and would occur preserved beneath the extensive areas covered
by relatively undeformed middle to late Miocene volcanic rocks (Figure 38}.
Pre-middle Miocene strata have been found in several places near the base
of the present Mogollon Rim (Peirce and others, 1978, in press} along the
north edge of the Transition Zone. These factors suggest that this zone
is worthy of careful geologic evaluation as a possible region in which
to explore for Oligocene-Miocene strata favorable for uranium concen
tration.
SUMMARY AND CONCLUSIONS
Twenty five localities containing pre-basin fill Tertiary sequences
in Arizona's Basin and Range Province were visited. Eighteen of these
were observed to display radioactive anomalies believed indicative of
some uranium mineralization. The general pattern of uranium occurrence
is occasional stratiform epigenetic mineralization closely associated
with non-red, low energy,·fine-gra-ined clastic and chemical sedime~ts
scattered in narrow, discontinuous zones or lenses. At the surface,
structural control appears to be subordinate to stratigraphic control
at most localities, at least insofar as the anomalies are stratabound.
Available criteria, including K/Ar dating done for this report,
suggest a threefold chronologie subdivision of the sedimentary rocks in
volved in this Phase I investigation: (1) Group I, Oligocene -- pre-
22 m.y. in age, (2) Group II, early Miocene-- 22 to 16 m.y., and (3)
Group III, middle Miocene 16 m.y. to 13-10 m.y.
Group I rocks have been the object of uranium ~p1oration in the
Tucson area, especially on the east side of the Rincon Mountains where the
Mineta Formation crops out over a distance of several miles. Anomalous
radioactivity, though discontinuous, seems to be stratigraphically con-
trolled ~y dark shales and fetid limestones over a lateral distance of
at least five miles. A valleyward dip offers some potential for sub
surface exploration.
The Muggins Mountains, east of Yuma, though of considerable in
terest, have been inaccessible to exploration and general geologic
study. Hop~fully, this region will one day again be opened for inves
tigation of radioactive anomalies that occur in probable Group I strata.
Many Group I localities consist of coarse-grained clastics, often
red, not known to contain anomalous uranium. The regional relation
ships between high energy clastics and low energy "lacustrine" rocks is
not clear. Indications are that each phase originally was developed over
a relatively large area of indefinite shape and extent. Paleogeographic
controls existent during Oligocene time remain largely obscure. Many of
these rocks are allocthonous which substantially hinders interpretation
of depositional patterns.
Favorable rocks of Group II of early Miocene age are also of the low
energy variety and notably associated with tuffaceous materials that are
sometimes zeolitized. Occurrences of this group tend to occur in west
central Arizona between the Verde and Colorado Rivers. The Anderson Mine
host rocks are placed in this category as is the lower part of the Artil
lery Formation, both of which have been intensely explored. The Anderson
Mine section emphasizes the facts that: (1) large volumes of lignitic ma
terials did accumulate during early Miocene time, (2) these mineral~zed
carbonaceous zones can be preserved, and (3) the "right" rocks are more
important than large stratal thicknesses. Anomalous "lacustrine" sections
of similar age irregularly crop out from west of the Black Canyon Highway
to Cave Creek near the Verde River. An interesting locality is near New
-4'6-
River where almost white aphanitic dolomite of significant thickness is
surprisingly, though inconspicuously mineralized. Submicroscopically
disseminated organic matter may be related to an unidentified dissem
inated uranium mineral.
Group II strata, though tectonically deformed, nevertheless tend
to cluster along the boundary between the Transition Zone to the north
and the Basin and Range Province to the south. Because of the relative
stability of the Transition Zone adjacent Group II rocks maintain some
continuity that should enhance exploration. Group II rocks in the New
River region are closely underlain by Precambrian crystalline rocks.
Group I redbeds are absent even though present in the Phoenix region
not far to the south. Though not discussed in this report, Group II
rocks in the Tucson area are believed to be represented by the largely
conglomeratic Rillito Formation.
Group III strata of middle Miocene to possibly early late Miocene
age were identified only near the Verde River, tentatively at Lake Pleasant,
and in the Big Sandy Valley. Some apparently unsuccessful exploration was
undertaken in Group III rocks near Horseshoe Dam and at Lake Pleasant.
Both sections are "lacustrine" types containing silicified limestones,
marls, shales, and tuffaceous units. Although locally anomalous, the de
formed "lacustrine" strata exposed on the east side of the Big Sandy Valley
offer limited exploration opportunities. Group III strata also occur along
the Transition Zone's southern and western boundaries. At Lake Pleasant
Group III strata may overlie Group II rocks.
-47..:.
Group II "lacustrine" rocks are believed to be the most favorable
lithologically and, importantly, offer the best opportunities for prac
tical exploration targets.
The presence of Group II and III strata adjacent to the Transition
Zone raises a question of depositional continuity within the Transition
Zone itself. Many of the relatively flat-lying volcanic rocks of the
Transition region are believed to be Group III (Hickey Formation) in age.
Group II rocks would underlie these volcanics and overlie Precambrian
crystalline rocks. Because of the general regional favorability of
Group II strata the relationships of these rocks to the Transition Zone
encourages additional attention. Access difficulties and lack of spe
cific interest have, up to now, hindered geologic research.
-48-
RE'FERENCES CITED
Armstrong, R. L., and others, 1976, K/Ar dates from Arizona, Montana,Nevada, Utah, and Wyoming: Isochron/West, no. 16.
Banks, N. G., Dockter, R. D., Briskey, 3. A., Davis, G. R., Keith, S. B.,Budden, R. T., Kiven, C. W., and Anderson, P., 1977, Reconnaissancegeologic map of the Tortolita Mountains Quad: Arizona, U.S, GeologicalSurvey Map, MF - 864.
Bissett, D. R., 1958, A survey of hydrothermal uranium occurrences insoutheastern Arizona; University of Arizona, NS Thesis, 94 p. abstract:Arizona Geological Society TIigest, v. 1, p. 47.
Brennan, D. J., 1957, Geological reconnaissance of Cienega Valley, PimaCounty, A:rizona:University of Arizona, PhTI 'rhesis, 53 p.
Brown, W. R., 1939, Tucson Mountains: An Arizona Basin Range type;Geological Society of America Bull. 50, p. 697-759.
Chenoweth, W. L. and Malan, R. C., 1973, The uranium deposits of Northeastern Arizona: New Mexico Geological Society Guidebook #24, Guideto Monument Valley, p. 139-149.
Chew, R. T., 1952, The geology of the Mineta Ridge Area, Pima and CochiseCounties, Arizona: University of Arizona Unpublished MS Thesis.
Clay, D. W., 1970, Stratigraphy and petrology of the Mineta Formation,Pima and Cochise Counties, Arizona: University of Arizona UnpublishedPhD Thesis, 183 p.
Coney, P. J., 1979, Tertiary evolution of Cordilleran metamorphic corecomplexes: Society of Economic Paleontologists and MineralogistsPacific Coast Paleogeography Symposium 3, published March 1979 bySEPM, Los Angeles, CA. p. 14-28.
Cooper, J. R., 1959, Reconnaissance geologic map of Southeastern CochiseCounty, Arizona: U.S, Geological Survey Map, MF ~ 213.
Cooper, J. R., 1960, Geologic features of the Pima Mining District: U, S,Geological Survey Bull. 1ll2-C, p. 63",,103.
Cooper, 3. R., and Silver, L. T., 1964, GeologyDragoon Quadrangle, Cochise County, Arizona:Professional Paper 416.
and ore deposits of theU,S, Geological Survey
Cordy, G. E., 1978, Environmentalgle, Maricopa County, Arizona:Unpublished MS Thesis, 89 p.
geology of the Paradise Valley QuadranPart II: Arizona State University (Tempe)
-49-
Cornwall, H. R., Banks, N. G., and Phillips, C. H., 1971, Geologicmap of the Sonora Quadrangle, Pinal and Gila Counties, Arizona:U.S. Geological Survey Map GQ 1021.
Creasey, S. C., and Krieger, M. H., 1978,Cochise, and Graham Counties, Arizona:Journal of Res. i (1), pp. 115-131.
Galiuro Volcanics, Pinal,U.S. Geological Survey
Davidson, E. S., 1973, Water Resources appraisal of the Big Sandyarea, Mohave County, Arizona: Arizona Water Commission Bulletin6, 40 p.
Davis, G.,easterntonics?
et. aI, 1977, Enigmatic Miocene low angle faulting, southCalifornia and west-central Arizona: Supra structural tecGeological Society of America Abstracts 1 (7), p. 943-44.
Drewes, H., 1978, Geologic map of Rincon Valley Quadrangle, PimaCounty, Arizona: U.S. Geologic Survey Map 1-997.
Eberly, L. D. and Stanley, T. B., 1978, Cenozoic stratigraphy andgeologic history of Southwestern Arizona: Geological Society ofAmerica Bulletin ~, p. 921-40.
Eyde, T. H. and Irvin, G. W., 1978, Zeolites in Arizona: State ofArizona Department of Mineral Resources, Mineral E:eport No.1,(MR-l) , 40p.
Finch, W. I., 1967, Geology ofstone in the United States:Baper 538, l2l~p~
epigenetic uranium deposits in sandU.S. Geological Survey Frofessional
Finnell, T. L., 1970, Pantano FDrmation,in changes of stratigraphicnomenclature by the U.S. Geological Survey, U.S. Geological SurveyBulletin 1294-A., p. A35-A36.
Finnell, T. L., 1971, Preliminary geologic map of the Empire MountainQuadrangle, Pima County, Arizona: U.S. Geological Survey open FileReport for 1971 at BG&MT.
Gassaway, J. S., 1972, Geology of the Lincoln Ranch Basin, BuckskinMountains, Yuma County, Arizona: San Diego State University Undergraduate (Senior) Thesis, 62 p.
Gi11uly, J., 1937, Geology and ore deposits of the Ajo Quadrangle,Arizona: Arizona Bureau of Mines Bulletin, 141, 83 p.
Gi1lu1y, J., 1946, The Ajo Mining District, Arizona: U.S. GeologicalProfessional ~aper209, 112 p.
Gomez, E. and Elston, D. P., 1978, Oligocene and Miocene developmentof the Mountain-Desert Region Boundary, Cave Creek, Arizona: Geological Society of America Abstract, Volume 10 (3), p. 107, Cordilleran Flagstaff meetings.
-50-
Granger, H. C. and Raup, R. B., 1962, Reconnaissance study of uraniumdeposits in Arizona: U.S. Geological Survey Bulletin l147-A, 54p.
Grimm, J. P., 1978, Cenozoic pisolitic limestones in Pima and CochiseCounties, Arizona: University of Arizona Unpublished MS Thesis.
Hart, O. M., 1955, Uranium investigation in Mohave County, Arizona:U. S. Atomic Energy Commission Report RME - 2029, 18 ,p.
Heindl, L. A. and Armstrong, C. A., 1963, Geology and ground waterconditions in the Gila Bend Indian Reservation, Maricopa County,Arizona: U.S. Geological Survey Water Supply Paper l64Z:"'A, 4~p.
Hewett, D. F., 1925, Carnotite discovered near Aguila, Arizona: Engineer Mining Journal-Press 120 (1), p .19, dated 4 July, 1925.
Jansen, L. J., 1978, The San Xavier fault, Pima Mining District,Arizona: Arizona Geological Society Digest, volume XI., p. 99-100,(Porphyry Copper Symposium Volume).
Jemmett, J. P., 1966, Geology of the Northern Plomosa Mountain Range,Yuma County, Arizona: University of Arizona Ph.D. rhesis, 128 p.
Jennison, M., 1976, Miocene basalt in the "Pantano Formation", ThreeButtes area, Owl Head Mining District, Pinal County, Arizona: University of Arizona Geoscience Department, Fourth Annual geoscienceDaze Abstract Volume, p. 16.
Jones, W. C., 1974, General geology of the northern portion of the AjoRange, Pima County, Arizona: University of Arizona Unpublished MSThesis.
Kam, W., 1964, Geology and groundwater resources of McMullen Valley,Maricopa, Yavapai, and Yuma Counties, Arizona: U.S. GeologicalSurvey Water Supply Paper 1665, 64 p.
Keith, S. B., 1970, Uranium (occurrences in Arizona) in Peirce, H. W.,Keith, S. B., and Wilt, J. C.: Arizona Bureau of Mines Bulletin 182,pp. 103-141.
Krieger, M. H., 1977, Large landslides, composed of megabreccia, interbedded in Miocene basin deposits, southeastern Arizona: U.S. Geological Survey Professional Paper 1008, 25 p.
Krieger, M. H., Cornwaili1, H. R., and Banks, N. G., 1974, Big Dome Fro.and revised Tertiary stratigraphy in the Ray-San Manuel area, Arizona:U.S. Geological Survey Bulletin 1394-A, p.54-62.
-51-
Krieger, M. H., Johnson, M. G., and Bigsby, P. R., 1979, Mineral resourcesof the Aravaipa Canyon instant study area, Pinal and Graham Counties,Arizona: U.S. Geological Survey Open File Report 79-291, 27 p. plustables.
Lance, J. F. and Wood, P. A., 1958, New Miocene fossil locality fromsouthwestern Arizona:, (abstract) Geological Society of America Bulletin~ (12), p.1694.
Lasky, S. G., and Webber, B. N., 1949, Manganese resources of the ArtilleryMountains region, Mohave County, Arizona: U.S. Geological Survey Bulletin961, 86p., maps.
Lindsay, E. H. and Tessman, N. T., 1974, Cenozoic vertebrate localities andfaunas in Arizona: Journal of Arizona Academy of Science ~ (1), p. 3-24.
Luedke, R. G. and Smith, R. L., 1978, Map showing distribution, composition,and age of late Cenozoic volcanic centers in Arizona and New Mexico, U.S.Geological Survey Map I - 1091 A.
Malan, R. C. and Sterling, D.' A., 1969, A geological study of uranium re.,..sources in Precambrian rocks of the western United States: U.S. AtomicEnergy Cowrtission Report AEC-RD-9 dated January 1969, Grand Junction,Colorado office.
Miller, D. G., Lee, G. K., Damon, P.E., and Shafiqu11ah, M., 1977, Age ofTertiary volcanism and tilt-block faulting in west-central Arizona:Geological Society of America Abstract, Volume ~ (4), p. 466...67, Cor.,..di11eran Meeting at Sacramento.
Olmstead, F. H., Loe1tz, O. J., and Ireland, B., 1973, Geohydrology of theYuma area, Arizona and California: U.S. Geological Survey ~rofessiona1
Paper 486...H, 227 p.
Otton, J. K., 1977, Geology of uraniferous Tertiary rocks in the ArtilleryPeak- .,.. Date Creek Basin, west central Arizona: U.S. Geological SurveyU.,..Th Symposium of April, 1977, p. 35...36 •.
Otton, J. K., 1978, Criteria for uranium deposition in the Date Creek Basinand adjacent areas, west-central Arizona: Department of Energy OpenFile Report GJBX-12 (78), p. 101-109.
Pashley, E. F., 1966, Structure and stratigraphy of the central, northern,and eastern parts of the Tucson Basin, Arizona: University of ArizonaPh.D. Thesis, 273 p.
Peirce, H. W., 1976, Tectonic significance of Basin and Range thick evaporite deposits: Arizona Geological Society Digest 10, p. 325.,..340,
-52-
Peirce, H. W. and Scurlock, J. R., 1972, Arizona well information:Arizona Bureau of Mines Bulletin 185, 195 p.
Peters, D., 1979, The sedimentologic history of the sandstones ofTempe Butte, Arizona: Arizona State University (Tempe) UnpublishedMS Thesis, 197 p.
Peterson, D. W., 1969, Geologic map of Superior Quadrangle, Pinal County,Arizona: U.S. Geological Survey Map GQ 818.
Puch1ik, K. P., Leach, D. L., and Cazes, D., 1979, Artillery Peak orientat ion study, Mohave County, Arizona: Department of Energy OpenFile Report GJBX-72 (79), 10 p. plus tables.
Rehrig, W. A. and Heindrick, T. L., 1976, Regional tectonic stress duringthe Laramide and late Tertiary intrusive periods, Basin and RangeProvince, Arizona: Arizona Geological Society Digest, Volume X(Tetonic Digest), pp. 205-228.
Rehrig, W. A. and Reynolds, S. J., 1977, A northwest zone of metamorphiccore complexes in Arizona: Geological Society of America Abstract,Volume 1 (7), p. 1139, Seattle National Meeting.
Ross, C. P., 1922, Geology of the lower Gila Region, Arizona: U.S. Geological Survey Professional Paper 129 H., p. 183-197.
Scarborough, R. B. and Peirce, H. W., 1978, Late Cenozoic Basins ofArizona: New Mexico Geological Society Guidebook # 29, Land of Cochise,p. 253-260.
Schmidt, E. A., 1971, A structural investigation of the Northern TortillaMountains, Pinal County, Arizona: University of Arizona UnpublishedPh.D. Thesis, 248 p.
Shackelford, T. J., 1977, Late Tertiary tectonic denudation of a Mesozoicgneiss, Rawhide Nountains, Arizona: Geological Society of AmericaAbstracts ~ (7) p. 1169.
Shackelford, T. J., 1976, Structural geology of the Rawhide Mountains,Mohave County, Arizona: University of Southern Ca1ifronia Ph.D.Thesis, 176 p.
Shafiqu11ah, M., Damon, P. E., Lynch, D. J., Kuck, P. H., and Rehrig, W. A.,1978, Mid-Tertiary magmatism in southeastern Arizona: New Mexico Geological Society Guidebook # 29, Land of Cochise, pp. 231-241.
Shafiqu11ah, M. and Langlois, J. D., 1978, The Pima Mining District,Arizona, a geochronological update: New Mexico Geological SocietyGuidebook # 29, Land of Cochise, pp. 321-327.
Simons, F. S., 1964, Geology of the Klondyke Quadrangle, Graham andPinal Counties, Arizona: U.S. Geological Survey Professional Paper461, 173 p.
-53-
Suneson, N. and Lucchitta, I., 1979, K/Ar ages of Cenozoic volcanicrocks of west-central Arizona: Isochron/West, No. 24, April, 1979.
Thorman, C. H., Drewes, H., and Lane, M. E., 1978, Mineral resourcesof the Rincon wilderness study area, Pima County, Arizona: U.S.Geological Survey Open File Report 78-596, 64 p., map.
Wilson, E. D., 1933, Geology and mineral deposits of Southern YumaCounty, Arizona: University of Arizona Bulletin # 134, 236 p.
Wilson, E. D., 1962, A resume of the geology of Arizona: ArizonaBureau of Mines Bulletin 171.
Vice, D. H., 1973, The geology and petrography of the Babocomari Rancharea, Santa Cruz and Cochise Counties, Arizona: Arizona StateUniversity (Tempe) Unpublished MS Thesis, 152 p.
Additional References:
Schoustra, J. J., Smith, J. L. and Scott, J. D. (with collaborators),1975, Geology and seismology. in Palo Verde nuclear generatingstation preliminary safety analysis report, Volume II and III.
Damon, P.E., and others (1968) Correlation and chronology of ore depositsand volcanic rocks. annual report No. COO-689-100 submitted to theAEC, dated June, 1969.
Tedford, Richard. unpublished manuscript circulated at June, 1975Penrose conference held at Mammoth Lakes, California, concerningPleistocene geochronology and correlations.
-54-
o 50 MILES'---~_~----l_.l-! --11
.1]3 0 __ --1 120• - - -
o/
110':
/.J
II(II.I
I..,\..
" \
)
I'd
) I
/ I
Figure A. Index map showing positions and general trends of the individualcross-sections, Figures 1-26.
-55-
50I
37'~11.4 •~=__
,II
/.
oI
_1]~ __ Ill'
~\Vi
I~Iti\1~'-
...... '-.
~
'1
II) I
I
I
r?-.--~• I1
i .. I• .. II oJ
iZi~hflO
l 'ties of Table l.' loea 1of the uramumIndex mapFigure B.
-56,..
NWtol'Jl.tf' ~Sb'·£J 2I)'t1jl'ts----...:>iJ~sJ"'ZE.
.sW.r.orn'rTI1S / R.IZ,c.
~d.II.t."lIt.,:tJ:i!1)'1O,il('3~
A
Tr
Cl'r\k.r ..-c.s:t u,c.T/3S, "'Z~E
Wi"<~..t<r 1l!1.. 0
t
on~ i~
ALL.... fl..t
t~F
~5o~ih(rn GGWU,.os
Is'" ~.." .~<\\"T'.ss, ~\"'E
SIl:c;.""[li.n
' •.J.
~ s..rl N."In,
~NSICl£J 2'Nl~1o~
Rin<o';' l'l11ns 0
miCa.. altA.
\-~~~.:;-:,.... ..
... ,,....itu
x~
HUlIIhl .. t ..tfol<~
S"Y
fJ" H;!L 5~"T~ Cr"}
_ ~vc.1'"
IloIc,SeH i1I! r, "0 ,
~PL' I "'it kv ~Kl.r...I
A'
A'
IV1
"I
r5Itr,ii.3~
t
- ':::'-Br .:'-: =h -~/-~'__-:._~1,.\ 1\'\\\'.
~F
w
.... li,;Fr.,t"ti...1"eJ - 'Tv....,.rlL, Q~eiltu. -'To.._",TLy r)o.., ..l:iT·c.1. _ II"'
S4:.rlrll,nt"s. J..ro'·lt~J in ruponSct to ... rit 13~/O""",..u ,·,Fti..,.
oC.\l ... nt of 1ht 8.si" f t,.)I7t frni,,<.ott J onJ. It,,,ti"d .. J.c" fl'll:ii1'oc't)r( Tocrr.<e. 4,.d fG"- J'l"'ujf,s.
mioc~l"i~ ~-~O-IO"")J r". -S.s;1l .nJ.f.,.. ..' ... rift,''''11,,(£s, rrroc/fUl;<s, f f ,L.~'rms. :I'..ch.Jt 1,1,. 6,', 00""fm. ru,"r U"".1,n. .1 1'Jl~ 'R:U:1. B''tcl.z nt.'J;,,,s..,,,.
7" s..." f... .l.ro Y/fIUtt. "'., b,- 11,11:"'11.,. L;:f"-t h1i.nM.Ol"I,Ot.,,-I'l"- Ei~:"-20 P,1J~"'c1"~ -YtL,,~~ voLullics
\,.;itk ';inor ;~rc.",l...1d ",.&\~"",nts .
C...J"i....L nVI.ls - 0" r·o,J,sr-uoLc:.anic. S:(.~;,"",.;1::s .F ot,".,-c;-.rl(. °1,("1'••1••• f .. · - 0, (- 351".25' "1) 0 T1,;••uy > 5;000 f"t"o '11,.,.< .,.mil'l.Ja. f~· ·061 hO'l"'"uh;,....JJ, "t.thJ. TOlolorA.& 'E.Nf. ~2"'rt OH ...J, 01...).
"hrQn BClsin h~-Otc. G"'r-uJ..~ r.-..lk..J,. ron,I.,.~r..-ru.J -il;'c.-,r.;n... ~Tla,..c.linh C.,.,. ~Otk. (.L",s1ic.~ I~d\l~~"" ~""",h,., ""... J. L:..... s1o"·u.
Hdll\c:1 F4111" - O~volul'l;'u - Kv I Cr~jCl(.~O\&S 4.'tpo-C;t.s.
c\uj,., :s.~~i,., ... "'ts - KsF,z, I .11 ~-L<t.,oiZ-,S'.lll'l'l.;tJ(
...,,;. .... Alp€. I Pl"-:c=.~ .. b~i__ :-;_oc.b (i",d::!H Ap4'\'
Figure 1. General WSW-ENE cross-section through the Tucson Basin, San Pedro Valley, and southern Galiuro Mountains,indicating general tectonic positions of Tertiary pre-basin fill sediments and volcanics. * denotes uraniumoccurrences discussed in text.
-58-
·rr>
~ ier-G:: j
'I\/I
lJi
-59-
I<c ..T... r E..~ .s~c.31J, ,1S J A.GIIAI"
F'-9t.1n... 4.L", unO. W}O"i"i4i".s. - Ada i, farK B~ds·
<~~ :s~~J i d' J....r t( J , ......
-ns, ~ q. f/!C;'/'l",__<"- ·····~il{1-,"!~'- .... ,
/ d... .." _,.;. ....~~.,,'''' J "f .' '- ' ..... ,,-olor... l~rO~II!> - _... _ '''_lo. o. ~..·D~L/. D.- ./'//.~/.'/'';''';r''''\:_.~1 ~ J J ,. . ,. •.•.... ". v~v~._".__ '..•/ ",r,ft, q~.'.~:,,;: .. ';;'<';")i;~':·':;1'-'~~~:;~-~·:~·~&~:t:~,?j';~~3~;/'~ J~" rJorrhtr'ati, 1Yyr~~t.r:~1"'.. • • - •• '/, P , • A ..... -. :'-y • @, r"f' "ll
r
~,., , .', .',,.." / '. 0 ...«. s~ •• v' "', I , .~.• • " '-,c"', Ll..,,~( .~ '. 'P., "~ /, ... -/-~
I
'"oI
i~;s "H" Yl'''fP~~ by oL"'sr"-... .l..J IASbS fJ>O".f~ If'ill.-H, fl~T'I. !J.
(j) ~J"iY fqr.k. B-tas - h1.b ...l" .<....... ~;>~l~ of.f6.M,LoWIu..1'ls ."Y\J. h;,\, ~H<'\J fh~';~L 5'r""M.'tS <Cfhtq'~I'n'1LUM..'! hor'3cm~ W~\'h .,. ...y.hl:. ttLI"; c:...LI,h'l. SDIL )DMS.. ~w 1nllil L'lVls-.s 01- .1r"1 color~J. ,hAnll'l.L ifClVtL:s J
..... .l. f"'101 w~ .. ~ "Ir,un'l5.h ......L,.. rto...s ""... JsT6\1U J'.1iftrHd -rhro"<t~$... SIWl, f~..,. frob .. l:.l ... ooerJ,qnk\1I .... ~s. ......6 SIttS. RIo),J, 1·...br~<~I~ 5 toO W
JA1W) QI\~ rJ ~ r~ .. .sW Ji((,t,a..s. Co l:.1ks of )'I~qr·h)'
xLLi ... ~ yod:s , .... .l. :,"'qt... A-r-r,1"..J.'l : ....N-S sl"rilts, Z5-1>:" J.f-s !o wU:'. '.® <SY'l."1\ .. ".\ )'"-11"",, WI .lsj......... s -c.l.. ysr<1>1'S ...·~h lOWIlr",ost ~... .>.s 11\ S'let,11'>'\ hIl,,,,, r-'l.d ~r;fSr6VIfS) ,r.. nlt~ Jmutd.
f.la~ <:<I'Y>\FI~)l.L7 " a in \'i,~ " ..,I'l.. f.... ll <...".t",1" w·,th.. ~lLin ... roc..Ic.s "to lh'l ""o'rth~Q,s~. 71.;,. Sth,,;ti·c1Us",~ f« ..."t,-..P In s\., ...L..y ~"''''''l.Y\<''", . L..c;.Q,LLy. • S~ ';lrt.~I\-y.lI~ ~..J.st.,...us WIH-.. rcl- or~~,'!
.... oltl, ... 's ~ ..... .:;fS" 10 ~2.0 '-fSo (~)l.)o ,ht AJ,qIl' f.. rk Ws .rll <.... ff ... '4 I.r Q. Lo..,- L'lHL f'lcli"Mtnt",k;,\. jr....A....s 1'0 th'l. 6-;L.. R,',,~y (\",,\.,&'y ) o...~ ""ff..l, by l-,1iY......e'l. 1r"u'lL~1 qoX.
® 6 .....1 ",,,LorouJ... c..blol'l. -to ~ ... Ldll.1'" C.<M9LalN\'l.J'Q.~s ",it\-. c..L...s1s S _..1ri,( voLu ...'l l4is'l.. S..,... (,' !i~, J,o ...l~'l"s
.M" w..\1 ro~ ..J.~. . Y(lost "L...sts. 0.1''l ~2 - 2.' J. i ... ° U';;l \-45 fJ-: strlk~) ~ 35 co W" J;, IJtr1 si~ i L'4",,,, ~it",h.1"o PI!.. ,( rark. b..d~. U.,it rrobOoJ.J/ refr'l~""ts rro'llI n....L. 4.LL..v.GlL f",n o..,ajor <.ol14v."LA...fo.s,ts. llf~Jll ...~j .. c.. ,:;l to xLLin~ rock, 1tp«',.... '1\.i'1<: \.Ii1hS: . W,thl(l ih.. tLttJ St1Utrl<..fS (1, H, 2)1raJn :l:IJI{ 01 C. QSII c.~ 4'l<..f"-ta.s.... s ~",stlAl ...raLy. If tl..'I. s,il"lon IS 1\ot ou-.r1".. ro'1'1..4 > 'it i~ ... (,.....r1." in}
U.fw",..l s'r"'''''<''l· .® l) ... ff c.olo ......c\ so.",ay .....l, ..."'-u...Il T b-t,b, .l'IP 1ow..,.-J.s, NW At 4-13°, QW00.7frorM tJ..... Wlllarl.y G,L", Rlut'f'.t> to.,:.t;< ~h k.\ i.... I<.fr·u· rOrl <If SIl<"~I~ ,ro~14c."s K/Ar "'1'" cn.b;iti~"F ~31:J.2.""J' (.1L)nst-tClJ
J"73) ,. H-31)'
lh s.'\,4."nc~ fr.~ .. loly. r'fns.. w\fS. ol'.s.taL ...1I ...u·,,,,L {OMS 4"'.1. b ·,~'ll ~tn........ C."""'fl'lRS. ,"is ",.Jtrl"~ isf~rt 0: OL",st~tk\s ,(I'~H fw.. ~ <1"~ 15' d'lQr1l.la"c.l.- lot!.!. (h.f~ ...". .l ~bal\. nll...rhl nU..As .ic.c1",,·,C.cJ!, cl,st"llrll...!uolc.arl"S 3 nuL,s to t~... NW of this (r"Ss-s~Jlcl'I>l r.,h"r.s T""t 1l\1.I'"ClLu,i.s of r'l.lht..lsJ ~ ...T'l ,,7 2'.3 - 21.~ ""1'
(Olt..stQo.l., "73, ,. H-:S<J).
® @
~
NE.c.on. u<.ltT1N,TI7W"
fE cr .... -; PMC."",",,~ 1Miu of ::r.M.... t"lt (11'1.).
li",\StOil't 1
NCJfi~'O"1\ flornoso... mtYls. J\~o.r :Bou.s.~.Lo ok. w'ls.1
MZSh -= 'fI\o.s03°"<'-""·~ ~nSd.,;~OS~ Wl.o:l ... :s••r.......is, L;"u s'h.......foL ....t,.. '" I;..d. I>~, .., ~) .)..r ..o,crn.
~t"- t05t .A,~ ~..<.. II, Fi"\,,u·1l. S.TSNJ RIIW".
-12. ..,,1..~-.
I(J'\f-'I
ill s~ '\ --:tt.."""",,'\' ~,A. ~.......tl.~ (Oc.c ~"t. "J".... "'<t-tt ,I'lbb) c.~ \~T",,~Ac.~.-J. J....n.l ~c.......M.Ir~' 0..... fl .,j Qh)~ we-~ '-r~~ 0..,.6. st~ ("'1) ~s2.'" :t J.£. rwI1 0" b.-..,;t.. (roc-\:. cl.su·i~ 65 WQlch4 rhyoh'tt t ..ff). :r "'i\\- !tscn:..lot... -u... ......<.'1.;,.. or (I...') ....... l..-tlao' 1; ......\:.os... f 0't.>"V\~ 'I: > 2.=:1 '\ th,,. ku..J. c..ic................ ~I...L. 1~~ ...:~~~-'-<~~ l,""s~ u.-..l.--u...:.Jc. J~ I;~ \...-.L...J. 'D-! '\"~ bll (4"~'C. nw.th )r\Illet'l on's:...sos o ...! 'M.IS~l<' ~
~~ ....;.M.. '" FS;s'~ <:.Gff'1 .....u..a ~eUt -yt fl ..... (l\o.1.l ~"-I"'t r). ~i~ oJ r~f~~ \-.0.,". <:<0_ ...,...~ .\,ou-\,;'" ~~...l1;~~.T"J''['~ ......J'm ~ Mz.s'" -..ii.,..... A"",:",Jo- .~"'etl.;J.., 4t _....wi ~ W '''''''I\t~ \~.. 1s SArt,,,,,, (J,.....rt<Ml.1), .........~ 0'1 !.~ Jd't\l '1\ ... N-l. 4VIk.slc..Cd\A'~..t.. (r.6.b..l~J ...w.,l i..... c.biy tl.j" f..1.1 ~;......~~ k~ .Nn", q,~S\<mA.-s\-J.... wN:t ~__A.~'l~ \~io \lc\ccvt\\('
f...J:~ (l;w.~!.to..1i( i). L,- ~ic-.l L.<~\;IT ,"tx J r.~I>.H..<..\;ty: '01 i ;"1~\teMJl2. L.....L'ity I to lb,. L.;..;t..... l I.~ to..., ,~rl\<f\'.N..
® J .. ",m-l,1ts ~ ffoMoS4, (Cl'>I~- 'nIbr II ~~ IWM 0.'> c.l>O.1l.SJl.. ~C.l\'" AM1- ''"ilCW\Ul..h,~ oJ tb t...... 0'\ !roM ~ ~ ......~'4~ sh.if~~~~-nA.or. :.is ......... wJ,... til 1.lk-s ~ to-tk ""-~ e-,(~ 11A41-~~.(~. I~'t~'rw'-~~~Illl-MW'~ Vl'l.sh,...:.tI.~~~~ aX Ro<JNI<\ \W~.
@ Tk.~ ~ AN,~... s;.t..:Xa ~, II.~~ -..\:'''W\.1'. L\:..N.~~ v.llf"w -.n.W'w.. r'\\.,.....".~ ~ ~ s_~ ~..u.u-..d..:p~ ............x,~ ~\l1I\.J. 7 .. f .... ; tl......"l .....a ,,.;;;r,,,,,,a. .... <. .,"'. (I ...'ts of m~sh, f(., .... , ~ T..rt,...r1 s.L or".Ic...... ic.s ....4;'/l s .." ....L vo.riic...Lly i r ).,;., <..\ ..siic. likt!. il\ /'I€.4 sf..~ 5..<.30, bioi, 17LV. """"" -&.Vn ~.. ~·, ...L '\II-!s~,....~.;x...;..,.. .lM..~ r.;,;;t,,,, t. HE ..s Tr.. "s,."il' ~ll.<t;CIVI.
ro:;;t.w. ; ."....$ ';"'"'l""r-~ 4\;~ i", Sf'lc:...Sji~ ......~ IS 1.1 1.J. fr i""""'rl..t.. ~ .1>~vOti..-..s c.~ , ....c.\,ui""s, ;)f :r,"'mi\t".-;r-.......-<tt "oT",. 1h..;i" S<....·, ..i"os·it, Cb...l~.;..'l ?J i.. m~..'h h...s u"'y 'S·,,;,,Li .rtt;t .\......s .,....1;...1 s .. j;_. l:his ~~.,;t' lI\.tl.s c.l... i f;"ti"",.
®-<,~J
C's:
.~
i3
to=?~
-62-
h · . ,.,.... . t l so tl. !I, TZoS ~2.'6E. J kf'~'" ...1.:<.1. i.. .,roJ· .j,d, th'l. ~"u.. ot 'U. /(~r 4...T.....\,;<1.,T IS. is. 0.. ,\'n"o. ~"'tQ. "'-s..~U'cN"\ c.ou<.ru'1 l\oQ: .... Z. , I
I~ in s~<. 3Z-, rl'jS, l\z~£.
(i) l'i..1c. 7 .R· .. ' ... .}..... r, "' .. ,\ ,roy uto'\'.!. s~~-b ...ro"'"~~ ~s ~f"tko. (l,:.""<...\. ..............b.......<.........c.....,~~ 1:.-tt... 1'I0"l-u.-.. ~ z."I-Z~ .....y. ot..\.. ""l~ r ..:A (b)~ <......t t .. 30o ..f'~ (....,.~x).
® ~r:"""<A.1~ -...a. ~-r-u ~(~)~s)~ I~~~~~o<.~~ 1-u;.~ ..;t~ ~;<JV\(,t.;u~). ~~--.~.:...~~~~~ k.,~~~~ ""U.-",.. S ....."'-..l~s I s~1~ ~~ (0.)~~~~~,\M,thurn ...111~J c.........j to ~2 ..r3x (2Q'()-30o..,.~. IIu.S'lt.'(\S c>M.i" ro.At1~~0, b..:t r-v-"'''1 s i" t~ "1I1LkD'/loUS.~ 6) . ry~ ~\~ "l.;.4...~ ev..o..1.. I...Vllr-~"t. "'WM.,t>"':'d' ~~~~~. s..-.....~ e:-.....-'t,- ("""2'<) ~....i-. ~ ..~~~ o! ~JI\1 (c.) an ... \i.....-"o;..~1·t~ff-!>\lt~1 ....., un..t.
®~~-~ rL-Ih~~~ ....'V.-. .o-w-.o. ~~~ 1'~ AAtt~ ......\ ~~,20,.~ .~. rOV'l-"'-~<a:t.:- iVt~ ~~"c:\"I"'" ~ E.......J Nf.. 1),,)U\......~l ~~~~1\.l~ ..""IoI"'i~~~.M". 'S,"i,~s~l b.;t (io-r...lly~) LQ<~ 1\.~..w..S ..,I,;,",\, 4.M ~T..."o.s~~ "1 &,u;" 'l-R~T~' A" ~1J\c.~~ ~&-b_) KIAr k.-t'ua" at If "PI'y- (th;s stLAJ y). Ay" ~"i~",<it;, "f~ ~Sc.""""r"~ it.. Nf. f.,A. \ tI-. S"",is.\Mll>\~ i:l. thR 510ft l.b~lIa1 (A).J".o..,..J Q"'~ n..y 0'1 'tHAy y,;):. \,........ \,..J. rl\l:.t.~.t1~- ~H~ht""<>-u<.-..J:. B...sin........A","""'Y-f~ l'fllQi.. r~s~ i~. i,,~V1~-t..A 'l\W. dS r·,t -a.~\'" II "".1, \...1 .,.. ..1 b~ b..s,t~r~~ \>1"t\..a. ~""""u;s ..'I: ('t)~~~ S<.bJI.r ai (J.). .
I0\WI
!W' Sw i",~h"LYA~ Yr11,,~.
r
C h·'ri<: ... \. ....; 'U(&'fOft~
. Mtns. !f2\S w. ss 'n'l.l~ Va lLfl..1 (,tf\tY4l;.3f.! 3-! vi~~ . \CJLook A#NNW- (3-~ "..~ of f,~lt \ /"
nils ... Dr"..,. (\<o~:),..~,:~ ~...-;.'-\ ~_-' l<.. '1-_{!J":'
(~,...-...-< 'f. ... ..... "'_.... ~-;.- ~., 'j,. IjI
.~~')--.-S~ ~ \!J'" ~ . ~""l(~" ~ ~ I.~.~ @f:~0 Yo G Itt
W(~~
Bou", .. fill ;s f~ ~. ..4OV::U.. a....J ......:tk 4i~ ""....", I h.&X ;.... "'-<>'t~~ tk ..,.... ..... ~I..i.. Oo'UI .... Wl<>.ot
~ \..-. ....~~~~ '\~ FJJ.t-s..
F"1LlY"f?. 8. CLo.l)ton HiLls. northwllst of G-iL4. BUI.!..
I0'\+:J
sw
SW CD' n\r ~5 .....,.'1,T 2.S, R 'z W"
1.$~c.Tio", off~~"t
~ I ...il~ To .5£
C L TON
15~ctiO>'\ oFts~ii I ":Il'l io Sf..
H , llS
NE.
j Sf. ....rn.r Sotc. bT2.S, R,.II IN":
.. ott., "" yUc.o~....;- ril1~ ~n:i:ts i. iht 0'\0.. S:U.,1tsi" 11.\ fr~" ..nc.~. of ..... oLL , "0."" l. i1L1[ ~i"s<.d,4 ~!;......ts f.., ... ~~ IZO- sOO ...1.0"" ...... fro",~ fL ..iL. ..).. .. L, ...1:••,,-, wk.<.~ w..s <....1" ""'''', 0- 't ...~ Cl......o" WilLs s...li....iits:.
eL....io... Hill~ s.!imuit~
@ Lo";u bioi.To!. rhyoL.ir'l (KJllr on ~,o1";l... '" :2.3 ± 1.4 ..y , :E ~ull f sr.... ' ..y '*10 1), c.ftS·lit'~1 of 1I'.. ~SIV'"rl.. ,--r1, .. rhyoL',t... To Icro'11o....k. i",J.. ,,- .. s. .
® m ...l- .lorl::. r .J-bro n f",irly ...~I' sorl'll o.ri::.osi<. s"n,l:s10h'lS> ,..I ....;"'.l str..T;f,'c. ..tia.-. J w,t" uny LO<'<lLi.. J. .. r..'''~ Asi n·,t" to 2'1.t1,;..I:.. Tk~ s-J..ton....s c.......1...·." on ... 4-'0' b~J. .f {i"'''1f L~.,;, ......t\cl Ls (.." ... l.~.. "},, lj f o (,. l".l.~ - '-Z' thic.k. of :5-'J.)' L. > ... ,,4.. .. b .. s ..L S"-lo'1hid~. W\O 1Y Ls, ...·ItJ,. J..ST.. ,l.c.A., "-oar......
l--: ... ;n .... h ...l.J.·'''1' f.7' .",rk.eu" 1. ...Is ore. L.,t- ."'''.1 1"..".... e.o/o,. ~ ..... ). <..o(.r is sr°-tt1 rl..,~...th.~1:.n .. ss .Lo..i" '0 -/Z-o In >no:St f l......"'. L,_S1o..4.~ .r' <.o"sr"'-UO"~ lor\:. lIl'lS"'- fo, n7 ..... lts,
@ rl.yol·IT.. 1"ff, l.itl..;.. <l"~ "''l.l~ ..J. if\ low'lr fait) " ... .1 ;"1 LLfw"r.l i.iTo ... flow I.r...c.<.; o.n.1/ or 4l.n ufL.s:io,,"I.r ..<.c.i", <.o..foi..'•..., <I .. , .. l c..lo.sis of ... \1 u';,fs r.. .........th ·,t. 2.0 - 60' 11:1'1:. • Gro.lu ;.;to f/o ...-I..."Jotl
r"yoL,T~ L:..IUQ I/y I'" p)qccs) .... J. V,..rt3 - fill ..a Li'tho rio]:!>.." .,. oT Uft e.o ...... 0'1.
® J......../: <.<>Lo ! <>- .. .los'it"... flo....- !,r,,,,,i,,,, ·It" ,,"Ji I-.ollow ...... )..~·.1 sfh oi1.. JS"- 30'1h',..k.
® c"ff''', li tSlo" .... , k;,fh ... l. ....do. ..i <:.\,. i n...l I"S ", ...1 st';"1US, 1 "o,,:s"~j';'7 of 1hi", 1Y h Lqy... rs h1;.~A",',t}....le ;.. .-r...a Ls l ...y~ ...s w"ich w .... -r -brll c.Jor. • r0.ls" Ih lo...~ f .. rt on!>, '" f "(I.;s ....it ....1"4. utl'ullf.r
______....,..--...!I.!!.:r!..:~~c.e.~~..~'"'!:::::!~, 0...'\ ,r,,". ..\,..,,<:tl;t info tl.." hr"«.i", jO"" of ® . 8 - 12' 1l.ick.otl-u rocks. ® ~L.yol,t ~........lJ ...~ I ... E-I>< of ....~\:.~o ... n ... ff'.; .. itl' . . ,
(j) Iso~r~a h.ll>. <'''f r.''! "1 SW-A.'ff''''l ~>DLt, a.s.it..." 6.fllr 0 z.~:l: ",2., a.rlJ f 'if....''1 -It lOZ.).® ,n"ssl<' 'r..... rr... > L.lnt.>.i~<1. i.. Sam'l fiH.U •.f f/" i". f"Li ...1i-. d.ir.: Jo-5"o~ roN 0' NE. •
-65-
® hills i.. p'l.rsf' .... <..1\~~ ",i.ll.W- - }'lot ... l..oll':. @ ~@.
~ 7 ",;l<.5~ F,~.IO. SiL murk form'\tJol'l h~Qr 6;Lo. B-UIJ.
Look.. <{"''l. north..
S£.c.ornu- Uc. I~ IT", ...... ~
t......r G-ilQ/I.;...
-\\\~
S...thcrn ,..rt of SiL tJI.r.l Fl>\ of T5"s) KSW .....c.r;b...l o...~ ......rp.J. "''1 Ht;..1L ..~ Ar_trOl\~ (11U).
-6
...~
......o
3\I'
g.®I
or.J
(j) Rc.~-bro"f\ f..",r!y wc.1I Sor1.! ..rl:osic. s..nast.,..u: , lIon-c,,£C......eous. La.., .. sCAl~ <,..os" -h.A,. l1h;c.lc..u...... 10 - ~o,) mo'tly
of 1ro,,-,h t ,pe. nOfeJ. San.l ...... .:I...rL..i" by rJ.in reJ.-LroLUl'\ Co'>1,Lo -r it" .....'t"L..... c.LasTs, S~c.l'\. to O'l <1.., ... iIi;"' ..L"~Itl.. v'l.r.-r; ....t CDr\t..<t "f~ r~ ,r.. ,,·,rc.s. h\o.,r S!> b.As {,A .. ly L.. "': r •.~"""'<t '\;sf l"1 ¥.,."- '3"tJ,i~ y ..Jc.J. I. ..A,. J
,..~; ......1"I'" c. of f/ ...i ..L ...~t,,,,",". S.. nJ. ..t........ ,nT..rrrc.~...:I. 1.. t .."r........: ~L, .. "'- ..nA .f I,u....l (rro,. ..... '", .h.lj..ic. ?) s.-ttiIl1~'Tb.c.k.f\US .f 5_.l:~.t_Cl.S III (rr.j<.<t....l) ;S(c. Zlf, T'IS, ~ &""E.. I' Soo - 1000 '1 l,p c..lc... L..T,<n'\.f.....1L te.. I Loc.... lly fm1ui",., ~ith) l"c... 17 4o<fO~~~ on irrc., ..~ .s~d"c.'t. c.o.it 01\- th~ S<IM!siOl'lu. ~os...!.of .. Lo l;"o'thi,1r. _ss'o".. cl..~r;~ flo",,) Q'IJ 1000-zooo' c,t "'~r;~- 1r10.... j."\'1\:~"'.\ ~...:l';"", • "",:;h. Wlo.nor fllA"i,,1.-s"n4S .1. c.1. ...n..... l ,r u.Ls. O,l.rio fl............1rix .. n!' fl .. ~", .. L. ~W11s 'o01h ,\, ..,dLy rll..s"'''Il>Ill.. lh.. lc.\J~r s", .. .l~",,~ ..... ,t.Tho. Lo r feme'.f sHt' j~ r..d.-b.... "",n , ..Lor, ", ..a ",..1..;"......... Q'lhi,J.. l ....iir;f, ..~ <1,'r-f,,'1 -r..ff b'lJ.. fLuuiQL.
·llIIbr;u"t,;,... in ' e L fo;"ts s"t'o"'jly To ...... rdS S .....a sw-. furtb .. r so..t\-" "Ili..~l 5u,\,..,.ts .. 5..d;...... <.onofOS"l'\ llfloo'.f f~A. qrk ic. s .l.rOO'l\:. of flooJ f Loi" Dr;l;" • oo)llrl..in by -1';00' .f r'l.1 ..... .1 .... I.>.r"..r 1r",y f .. nllo...cr~'l..
___.....-'-:I~n l<.nu L, tl.. 5Q"htl»')~ Qllcl fQ ..1l.... ~rll.trs .ljt 30-'10°10 SW- ~ b..t sfr',h J,':«1i~s SW'~1 Mort E.-W" it! NW*TfS)lS>W.
@ 10 0.> r..t t «:"'.,51.... \,.ll up ~)' J. .....·,li·c WillA'!.! tuff lAll t~t"'l\;ti·l.. s1r.. ,t... r<t <lVl! Ifl af hu"L hI" .." ultrofJ.yr'il ) en! uIlJc,LCl/;'
~ by LI'1~1 <:alortA c.obbl'l.Y m....lstol\\:.,s ....~ic.h .it> 1I0i ruc. ...hl~ 1.0........ f"''''1 I ,,"<t<.$. D'fs to SW ..... J W" ...t '!;"-/!;- •
• VI ® Low r~L"~f cu..to. hQ.14 "'f' I>y IloIlI.l.hJ rl.yol',tt or ! .. ~,te tuff a ..1 .rlrc.t.t~y ", J.c.rLQi", by <1 b..s...lt,·<: and.....';... "T~ff ~ ..,,' b .."","
T ~.Jt4 ~y ~be.rll f sr""Lty (~'11) ...~ 2.7 't 3.~ ""'1' ,hts~ 1.1,;,;.. J.;, .-bolo TJ,~ SIAl', but arc. ~'f"r ...1.c\ fr.... Hs1
:. of ~..,11~ by' sLot:" - c.ou .. r<tJ. Qre",... (J-'l,nIl..rQl j,;fs ..f ®......A ~ C-aytf~, .... to ...-J&lIsiv'l. "hi~ flow s..\",tnc.'ls, ;. \.,',1/5
: -r~ :1.'1. NW (®) "h~<~ ~...... b. S -;-0 b.. a"fOl.i\"lern"L. on f~.y..... 'tH In SW~ T.JS) ~ sur ....1,..1( Sl~ l1I~rJ:. beA.s 4n ro1,.!I¥--,.~ 1iI1S""'1' Th...s. sln"l,,,~ str....-t l .....1Tjt.. .1 ... rro .... rt..<\ Hel ...dl 10 s"-11<.!>; 11...1" hLt urf'-l.' vol~.. n'l S,L l1I~rk. f ... (Q) flW--'IS "'~y ~It f",rT of -n... c.;l1....S.I\I~ volc: ,c::. t.l(,ra;1'\ To ih.t NW"I 4.1I~ ::;''f r...t..~ t-to... hi!> Lo"''' S;\. ~~rk !>c.6,;W\,nt", ((f) f(!$) by ~
~- /~ ... ", .. ,,,lqr Aisc.ord .. nc.<t. ~l."ly ~ S-r... nley's I\J~r A....ll1. c.l r'! "ffLiCl.S 101h'l urrr- uol."",,·,<. S"1 IAUI C. .. J .... " is 0"'1..... ",.n'n"""" " .....be.. 0" "th'l. Lc....... r S'l.r"",~ ...t.... ..
N,;t., I A ~w........ ~ KJ~r J...i...cl. ....... M~S 't ®AJUW..o. t; - 30~~ ~ 'S1-............,1A.... , 4..J.. (I,71.J f"~ \7-21 IMy fM" J
~~ .L...jos an~y~ ~s. "'''1 ~ 0-2.5°.
I0\0\I
(D. /W.~" f,....,., f~. (I...) -~~)~,,~ ~s wf~ S~~- -"~ ..... v...r1"GooVIu,. ~~~.1 .s.c.~~ A4th 'N-'6'0'I. /W.- ~"'I\ ~ •
~ (Ib) uM,t.;~~~JLA. ~~~~I ~~<fMA.. 111~ Itll~~2~ ~. ~~-~~~~~~ rGfl.tl~' ~A·~ \w..t.aM'l~~ ...'-.'" ~ dL. N~l;° IN TM.oo.A"':"'"~d:Jt.w.~ W1M...MJ nl.... DM~i.. ~~ Th.cM~ \'WIM Jl"U...~! ~ ~ P""MPi~-~l (J~- V'Il~t.. ~~~S~~J~mi~~~<.~~.~.?" .s~ ~~ll.~ ~CN\!>. f~.~ ~ M .f-M-~ ~..:J;t... t..~~~ J.,.,UM... -to ~~...... ~~ CAAo.~ t.: W )\o\Q/'l.cro"(\ 'til f'\.IJ.-~ •
®.uM.u. ~;.;t. ""~ Wi\Co'\~ ~ -tt...~~. la...AA. .... S' o' 0'\ ..- M~ J",lI.J. ~~ • ~~~ NSO"W, J.lr If!;''SW. /r;,/Ar n'\ ~w..o-et~ ~-.i- "17.l.to.~llM.y-J 11o.is~ •
•~ \¥I111. s-. o.lo..o Gn~ (1<\1&).
~(j) ~p,J.~ ~~o~I.~j~~. ~ba.l..~ ~0'1~"~ ~".,...Q.. ~~ <1>'\ r-e..e.-.~ e ~~ 4W.AA. cllfS 2.0-3.0" NW.
~ ~~~~~~ r s ~"$S'",~ ~s ..:.JI.. ill-~ ~~) ..-.\ ~~sCt~ ~-~d.. ~~ . .f~~~ Oo'~. 6~ ~ ~ iyr' l'L6~ oM. (.\~sts. a..J.. -to I J..<~~ ..~@ ::::'::'-'1 ~o.M'Y\Ioll- ~ 1:. ~ .... fh"U'<lL~ ,..;vtt- b~~J 5~ haJ,.o.. b;t-~
* ...Lt~l\QL.I;~~ 4 s. &.,\'I.tds (m.., 1'~'1J is tt,ot @I~ f'NCA",hAiQ" ...a.v..h,A "'f..~....w ~1.J,~ ~.i..ti ...J-.c"",t~j E9 ,s '" ~,~ ~.....L..1-~ ro..r:t ~'IM ~ Q~ 1U.4WS at (I~ • Or, I""'hys (Q I S hlo'A~.(.;tL..~\ .. ~~bNlC.c:.lo"i"tsnc.~~io N.l~ ~'J..:- 1<. ~s ~ @)...l.-.- ..... ·....·'t'r~ ~ e..-..~.
I0\-....J1
(n-3Cf) T","f"'- B..its. Fi~LAr~ \\. K'l.!ba.h ;'/1 Mt\ro~oL·\tdn rho~YI\x
/7,(, "'.y. 7 / AL\5-.9.A R,';"" w.;,~"',;", I~~C\.~ ~<k~'" _ ~ C I \ _~,••••••• \\\\!{I;.If) -. .0'
~~":/ .. ... .•..• 'IIJ'{"~' .~" .00'~~ '" •• /. _~_~- o ••• 7..<""";;~ ......4. liff"CE",,". c1"~,,c,,· ......o~~,'''.~~ 'y/,(~~/ij':::: -=-§==~~~",,:.;;;;%: ••..•.•• ~! .. IIII.i\~~.!"~,,;"'~··~o~<·,-'';:j7
®~:~ /'////0;// / 1....... ::= -,,-=~...:...~~?':7o~;:'".;. .•.~: ~ ~.;~~~. \\IIIII.~/~·~.;""0 ....:"'....~
I//X ,/ / • /? /? /, ..~~,,,//., ""..,,~.,;- . ~ :~.Q ;'-~ -0,or•./;:':'/
2 ~ }'/// / '/ ./~o':;:'-·';~·~~:"~:"7 ! I) iI/fb'·· o::-"'/i,~,,"'-;''': \/ •. ~.O/ I'~' ......":".• 0'.........-
~ lb •. e/ " •/ / / "/ J; ./
,-",,"tn.. sj ~<.\s T~st~ - f~ f~ CL1itvdJ.~TIN,R~E _ 2.'O...u..._ ' 1 ~l3JTINJ~~E
e-J.W ~I\..
·i~1or to 1hi. ne'l~
·,-..j
111I..:1
LEtiN
~ !:!j
f.,J~...;~ <:!.
315(/) ---""'--r./] e---
-68-
1j.,jn .Bons,," Ls. ,,"J. '-~1s.. DVtrlA;", b)' l~-t..rr<'\c-.... 111'&.
<:«llt,,. ~'l<' \I J
"o'"',Rf7W-
-~ ._.~-
FI114r~/3.
OsboJ" n~ VIas h., J nlla r fa rb r .
Loo!:.;.., NNW-
ill liLttd r.4'b ..h of u..r·,,,,bl ... '~fo~·I1"to...... At 14. th.y c."l\~'.n Mo~tLl of arko~';< sallAs, 7fl c....jr.. 'lIIi"~r",Li5ai",,,-1.;;11. ...;"o,ll.i.. 1'QucL LllJIscs • <""~ ... r'l. l'-,L.t - .... tJ. f'-tJ-J,,.o..,,, ,.1.,. ~ ....J Jisr"'r100~ L.....·, ,. ..l, 1M0r...... <o .....oM/y• c.l'oSS- 1... 6.<rl",. $ ...... ,,.oss-1o'l.a, foint To So,. Sf. t,;,- ....,. d q s1....of ho,~cl.
h1"d~101\~~ or }, i", ~'''''l :s"".).y b.Js. At 11" 1h~ rL.lI.'£I~ or, e...L.:::.o,r<l."..,L, c~ ..~,;te..l., l.... r,) , L'l!~' fOrM'\'l' Ll,"tsV2,- 2' tl,;ck of sub'l.r".-l p",',;'"s of fl"lIio..l.. Sel".!.", e.O'U·S<t ,r",~",~ J JfL,,"" l.<,,~ts;, <I."J ':Sf""c, ~/",u;4L G.....1Io"'crQ~s.IA.. Lo ...... o" ;...br;' t;.'" to th'l norih 'V.... )" ..~. H.r, tl.... ~ ••l..l"...as «Mi4 i.., Iot,. of ,>iTuh..l.J...aqRJu:il'll fJllWS} Q~J (V~
\" "''I'" <>.",1... f Ll c.o.it~<t IN'~h '" yo", ..,tr l.elsoLT- t~yoL\t~ flro',L<u11( q~s.",b/.alt. t1 ~~ry S/j,,;L,·.r q.s..Mblo.1" 1.$, S'lcn
J 1e. J 1,..1' Iwu. ih.. ,"nJ.,~Il'"" 'SIt ... 10/, '" f",,,,, h.... .lr..J. F'l.Qt af r....l.l4s. ( ...L.c .. L;t~J 'fIt,q'HOSS"S ...t 11, ..ro 3'00 J
",,:t 1-:- / '~-"70001 ...s;:>UHlI~' no f.".tt (tf:rir,~s.. D'f's in tJ.t r.~blll's M' s1""",.ir;e...L ..l,ooZt <>. )J1lI-.lrbJ;"1" ..ti<.L",o.L Q,XIS \rJ~id, i... " b. oI>Sor.,.j,lI,ihaf,~/l 1°"'1 n.ro"'1~ thl i.h"t.r af S~-gJ liON) Ri7W. D,~ of YldbAU1".ore. 'So-Olo ° "x<"<jJ rotel,. Q, ..it'e.L.;..... L cOlis.
@ ,hie.\<. :S'<.i,';'"s of l.u..Lt flowS J 1.;itJ.. s;- /7) Os W- J.;rs. TJ.Qy loOt,.. obs.ro"! 10 outrLie. LI·,J.1 - ,oLor..~ fJuui...L ,.uJstl>1U~ ..a c.h",nn..L ~r4H.Ls ci.t 2b J anA ... Lithic UIlIAKI.d..IlJ, rl.yoL;~ f",ff kJ.. 40t 2<... Two X/IIY .l.a.s <tot 8Jq"k A k.
4\('1. 0.. nt .. r/f .~"I~"L.....-t f 10IMs, 4. 20.± 3.J "'I .or (~J. ... r1y ....1. S-r.... L'l.Y , '# 'i') ... n.\. ... II..'l ± 0.7 '(flt '"1~ ( DQ, h J
<It. Q,l. , 1170 A.E.· <. RAfTI ,. 112) • ZI.' 0 .. \'"",........ FlO\...@ f. 6). A.. "'llt.nS;lItt 5tr"Uof s.aim'lnis ~"1 dos" XohulI.A,) o~ul..,'n hy bQs..LT fLoo:>,S • o<:<:.ufy;nj ~u.Q. e.o ....1',.., h4-tL.
",orih .. ",J SOUotl. .f -N.., 0;// W;/{/~"'S /(11l,r ) ~ ..a o1os.llr",~a To -rr''''''Qi~ i"h~ rqJ ",,,I::.osi<:. Sel)olJ s"d",o... (lcJ lit tJ,~
£InCl. A t:..JAr JQ,t'{ .f ".71:0.3 "'t fl. ..;sts for ... flolor ..-rn,J1 hu-. of -the. bQ.S4li"~, t1tc.,~ 0 .. this <Yoss~scd,~(AYmsh·o ....." c.t.QL.) J<H&).
® !\I.\x·,l.."y Cross-s'l..c1;<1>\ ~2r'R-,LH Sf. .f lVI",i... on\t - <:. s·.~-ts of .... J2.00'.s"t,~ of lilMuto nu J.;fpll"J 30-1J~"sw~'f ..r~,4 fro"" ... .s.e.ti~ of 1"';ss ",',t\- .1'l,,1Ly J'fp';n, L - Q ..,lll foL, .....t',~ ~Y'" ~o- c;'AJ. '!"ShC4tl~'" surf..<.t ". bw.ut":"sor~ .sLi'TLtly r ...t;rY3f..LL1 QJ..) ..r' noos1Lr L'1J.t fo ....,.1",/01 1""1 ""L..,.s J ... Ill disr!...! J-!> bC.J.s 4rLJ I.UI (o',,"IM e.kc.r7 ",J..J~h"63 ,,ns. ChtJsoc.ol/Q -: h'l",,,1/f<t )ll;_.,."'liJ.-t,;.... co.......o.... ju~i l.flnto,th t~Q 4;sloc...1.a.. "..rfocle,. J ~,j JoU tI.1 t.x"k.s.J1 <\boQ~
',t illt. iM Li",,4omtS. Lilllc.stOY\CS o.,,~ r'db~Js w~n not obStru.a lo,dht" in "litCYOf 411ywhtr-t ,..;. tht Q(t4..
@ ~'lJI.......tLc. .J,."...j;~~Ul "'" ~-.-..<Xi"""~ """'-",,"" \ot1:I'~s- ~CoA.I.. f.t....k. ...... citO'o'l.
10"1\0I
,I'll::.
-~
Ct..to.r SIAl 1 S 7 1TI,N, RrJ.. J
~~
:1jJ,
.... x y ~~f~. ~),.~.:..-
II • '" • • f'--@
,___ J J( lit
--r;: J( It 'lC. .
F'''I~re.. \'\.W~~ VulitWl-L wrtns. )UQA. BL...c.k Bt.itk
Lc.ok NW (:)1'l- 'fi20.0 wt.y.
swI<:~nttr Nt. ~ ~...c:. 2.~,~ T'N,~gW.
-----";~
s~c:.t;OY\..
...,.\; -~ AUl-I"...,..", £likos;c e:. ,I""""'tr.;:r-<t, ... !.o..l ,/o-6o'1hid:. > ... ,(0 1" .J.~fosdJ~aL
"'(01'1. 'r.....·,ii. col.J./ d4>'t~ s... Io- CL ...,.. I<>.r 10 S ... b- .... "' ..~ ..~. S (,"- I"Z: L...J.s o..r'l.,r"sy. F... W' f;nH "...: 4 f, ..Js ., Llt'lr ..~", <:ol .. r • Clasts o/tll)' .. f 1r"u,;tt - WlO "'OLCo.~,<
c\ .. sfs .."t't!. T ... br;<.«t"';...." "',,<Hi..; .
... Y\.I... ~·lr~ F/...... s 0. .. a s .. b.,rJ. in ..!,,- 4O.,hs:r'l. flaw- tr...<:., ;"'$ ~ c ...L,u Lc..T.. " To -1000' tt.;..k.®
T,Lh!.(j)
.,....
oo:>
IoN
-e
\Y\~s-r fI.w. L..H 7 h ..l •.r;~ ... I{l ""ll-\n..1 ......J- ... 'l. ...i h~(''td. Bn.c::<.;...s for.... L..J., 't s.
t~<. b4S",L 4nd't;,r~ , .... l,o...:;t /0-20' .. Iool>( Tht c.~11"",,~r...-r1l. I ,l.....+(S o.t 20.0 :to.'1Z ",.y.(t\ois I'tf0rt)® LQ. ...~n..j"ll.4 .,.. ... l.sj""'<;:.s ;..l11 .. c:....L~~d ...·Ith. -t..... o ...Ilric:; r\',QL'.tiG o.J>l-. b<.~.s. 1~ .. lo..... , of ...~;<.k.
;~ 1.~'11.;d<. ""J. fn.sk.. uc:; ...,," for ... b....s ...L ~'I 11.;<.1:. L....to ...·,t'l. YiI...~sto"IlS a.rt l~i\" blAH <.olo:-$
",,,1 so..... wl.",t c:. ...Lc.or ...o .....s. 1YI'~""'" nor .,ar..,L (ur.. ;.. hor;:s0\'ls b'l .. ll....t~ lovo\Y <II"~ b'l.J.
<'0>\1..;.. cqr"ot;r<t. (~) t;"...\ 1I ..{"1;<. ..L f,.c,,1 ... ,... s. (to 2'tOGf~' fit <:o..r..;n;", tl..... c",r"ot;t'l. ;s .....rulll
0" fl~..;.l .. ql4"~ ... in SWf $w4 SIte:. H J Tt.N, K&Ill. Vl\ .. hioil..,. <:....t4j.. tl-.; ... d"-]'stant L0.1 U$
• ~ of vo,rlo>c.s c.o\..ors. eo..rs,,. :s.. .1.;"".. ,...is ".;T ".-t~ hllr .
¥ ~ c ..ffin, b..sQ.Lt S'trj't~ ,d;,s Sw ..t 100
I ..... cl. d --r(~ .j" 1!>.6 :to·1J WI, (this rtfor-t). D...t.J.e s4"'fJ~ G.....~ fro ...... -tht !>"s..... Lt.s cabou;1" I lMik 5£ of tJ,\ <rosS s.,a-;...... ilk is rnSl-lmqb!y S4mtt
ba-sQLt .s'l.r;~, ~tqrJ7 fl,,1- Jl·k1 ..... A. °ffQr'l. ..ilJ, o"vLyi.. , ... voL,conoclasti< s"lLtU'cot 1101 5ttl'\ <it ~...® L<t.... c:. .. 4r.. ."t~ ... illv N to> NUl rrt"~i"1 r.."j ......t'tllS ...... l ..\so c::.....T.... ;.. i", W1 ..fi,-n·<.l-. J',ku.
.....°
.....e...~~
I-....JoI
-71-
-72-
....73-
"rob .. bl~ i ..<:\"o,,·" c. .......t", <t ""'It\-..U\f1 <.o<lrS-\ 'fQiH~ 'bo"LIl't.r,] b,A,S. - ill rQrl
ptqss.i,,\ 'l».1A~t\oW5 ..1' ~,,-\.r;$ r\~LQs. Clff of
hI;\- slope-so Tn rl ...,,'S ,'r\t"Tb..U-l.",il-k
~1"lJiQL oll'l.fb..."k.. ~,\:\"st",,~.
NENt. c...... s 2.'S
T/2Nj RI3W"J Iv ~ ~~~~ '~ y\'1~
\-:.: I ~ -. I\ / J
fk. \ -. I,v . \..A..t,L 'U~
(flu,)I/
br;,~t 1f4.lt.Y\ ~h"llt. J w·lf\-. l,mor H) llIht) thillb tll.!s. I th;.. iuff b..l. to 200 Cor' - ml<<'L..~O)\r o,<.t,·u·,tr I~ iI-is u...it. - '0 - 100' t"·,c."-.
~~rowl'\-r • .l. fluu;qL 1'l<s '1JVI11~"'tr~~ CJI,Losill1Q, .lo'rkick I<)..q. hll.lt-n III!st ~'l\l4tr'~) Wlll'chi. 1ura c.o.!.. i"~ "srr",LL r~rLitt Co,c.or.l..."t 1lo.S~
0 .. rllA1) for '4Ar J.4tinl' tot.. L "-'/Sol tilick.
k/Af(w....oloroc.k)= "., t.o.Swtt ~~;5 stu.!l)'
FI"' t.\Y"e. I~.
J\rtiLL<.ry fm. - YflaS1{rSon. (Laims.
•<:-..:. f\ .,1·,L\." Y f m~ =- :>
(7Hl.J 1'1.'1 ""1
_2.11l11lu-
~lI(SI~ <.qrp..d bl 1oJ..",. 11 t.. L~t. tlll\ Js I
""t!, ,,,.. it l'llO!>"S .....~ f"u;i L ""s,t". t'r\ ..i"
...~..r;.L j" i~;11 b'l~h~ ls l;",.. V!;~ " ..J.'l.'
....ASTlI'I,S I ...11, uu 1. ....1\ .L"Y"r..cl. , ~..-rt-ol'\ fClrt01 s.~icrn I~ soft, f....bl ... fll ..rl ....-brl\ 'rM.isJ
s1~u:. ..,/ oc.c...s,·"""L Ls, h~. Wlost ofs"-<..,,,,, (""""'t~ It(l- 20'tl '1'1 - 'n.;t tor Ls!
("rt'I~, roc.k '" ""It. "rO" is '" h.. r.l. ~ro ..~hC.n, c.,lc.G1rlllo1A.s q.rk..oS'lo
5W\ ((h1..,. Stc. 2.7
~ Tn.N, '/3,..
I-.J.p-I
.:f<, 11.·1~ i...J.\<.c.U! i:,t.,:.J<lUSS fr""" A.:-t ~~l';'" is Qb~ 2000' 4SS~":I.'3'1rm' of a.J'CJl"1' .l-,R, ?/,' rAU"'''Y A.lt.
bollS'lL Artillt tlb,h
to Ar1i L.Luy rk.
-IX, \
N<....i.n :i\e. ~!;""
T /2f'J R..J3W""- Lu,c'ty four (L~;W\s
qr"\l~ L..<.K.l ~ ....... (\ .. 'I,",S ~I.I "&f
AttiLLllty f m•Fi,u.r~ /1.
- IS ... ;Lt~ ~
-....0,"\\1 \.ll~'"\ ...\ii"i..JII~n
---= i.... ..-/l/~//""~/. ///" ..../-;......-..- ~~ // .... //,::::---/ . .
,//..... .....-:.;1'" .- \/ /"./ /", ///"" /.',/ .....//~~:/ t /14~
........./- f,II...., ..~st
........ "l(Cl· 1lllollli~k Ls.r:,1,1 rc! mlstoll$ bJlj,s ~QO-bOO C::f~
(--t<> ~)l)
5ISE. (or.", $'<:".1'-
JTI2.N, ~llW"
\
\\\.-- -d.,k ....,l Lil~t
Volc::onl(~ ",..kt"r h'llIs to $,r
"-JV1I
MT.: 1'1\1l.'S.~ t\\ow Ls. T .".,h'l1\'t.S <:.\"-Q"(\1 ;:.......'- ~o -th'l..\\o'rTh\>1'1. ...1 to 'o"C.Olf\"l.. -t",,\ I,..s ~ ~..i t\\C,t <;Qf 1\,,f\,titL,ry fM. t~H't. 'S,.,1t'Ylllt .\.';""I\O\o.s ."''''v~bllll'" r\<o.c::"~ 1.. 1:M .....i'in. ~,\',I\\Yl r"", \'\n~S ill \M
oV'~ •
t- 0
-76...
J-...,J-...,J-/
fi'j ur~ 2.1.
~%~~~-~
I/~7v""~'-L J.". .:yJT"~ ;
----(0---''
.s W 'or.., SQC. 22T8 J{ !tIOW' ----.!> m',Lu_
SSW J
Ho.r<:'lAlla r 'Mios. - BLl. LL~v-a P~Qk. S~c.tion.
?
11 IJI urh. SU 3(,T"IN
JA,/o /I{
NNE
~1v... 'S ..e:t..:..-n k A.:.rs SSlJIT' oX 1~-70°. S.... sl:.J.....\.~ OY\ H"",,, .. ~CII\ - R. J-:l fo.h wi,~ for x-s...c1";"l~ .~V\UA. 'b!>"~ -~soo' ...ss..... ;..., ~of.....L' r"p..'1'iTiOYls)",,'" \\0° 0.\1 0. f "1' A;r ,\'1..
(i) ~"'~ t.>f~ J ... rj~~ , ... .n-.A~ t..w J~ eM -~ ~. 4.fs So -lt~$.® RU-~~~~. \J~,.-Jj~~,~~~~$.~ ,...,.......~\').;A:t. >&,o,~, ~~ 1 fE."Y'~1 ~~~~ W ~;kJL,~ 11J-t. ,-~..t.:U.~ (U4Imik~h-o.J)} lllV\.Jl. ~,~. cl..it.4~1.. UU;~~ ~ltl so- 't""'t)~. No~~ ~.
® 2.- 3.000' 4~ D..M.J.~ r kc.dQ.s. A ~~ ~~ r W\J4I\ ik~ \ tk~~~ Is.1±a""'t J~~. Car-t- \¥oM\~~ (<J.n..,~~J~ .....~~ -tt...w. l...M~ ~ -tt-..~ • o..o.J, NW~~ W't.t-a,. ".]I:..l. 0.....~
~......1:..u.~ ..A .......J.~ tk a.:;:;t~. A~ E-W r yo-' ~.~ W.:tl~ J "'\~ f'~o;;tt. J
~ Cl'"t,J.......o..,~~,~ WI'M\~. No~1\~'"ctlv:J:, W'lS rWta.!.®~~ 'V\~ ~t\....v.."to l ...k...r.s ...\";,,", ~"-"t. "...---...... 10·))·' , "" ... h..... s.c:.ak.s1st~~~~~~hrq~~oVjs. I)-
® Tlu ~~~<:A..u.~i.~~~-t.;.t...~~~""",~~";"'1>4~~~ -t, 1J-a~ -tt4~ -tL~ sW' ~ 1~ v.rt""~~ J i,e. -u...~ <11'~ \tl..l>fr-'~JI.tsk~ tok~~~ t; ~ ~'w~rr~"".
'"......'e....Il
-78-
· -79-
/'
K/Ar s",,,,,J .. of b .. s"U Lo-mQ.S fro ..... "'"~0"r'1 </.xro.~A.. H"l<.Y I.Ih~~l... I!> vory p,,,r1r .:til-a. '5........ siJl~-u1'(.r\.;" ro, .t, ..... o.S t;... p..saL't ..l>olJ~.".,..,v', 1~. only 1,'. \,.1""..,,, th<se S.Lt,·...,s ""~lh 1\.\,"-" lui.. w-.sh, s.c.T,:.v.. {5 1M L,;""st"""s
f r<$.;;\ '''' \,011.- oM4.S.
Co..1kQ..,-"I"Q ~ rA;c.h a.~l CL<».:"",~J
T )b~tJ tt-,...J /7 N j R/2- W-
e;1 5~ly!.(.-tt-l~~C.):~ Wikit_'up__
l"oJ<. in1~ \'l-cn..1ol NW ~ ~o:.21'L ~-<'- 3 yr.' </.:5~
"ft"r ["M'] rr> .ds t .. .\"J." •fo 400 t..f~, IfOT'c'(t~d "''''''''1
,. .,n'l (~r,<, 2L1.
..----'_.-
SE~ s.Q>t: 2"3
W:t.,. \~ \J- "l.'--;:t:.-v--
t1,., ......-.L.n (e U \
/--
~1in s.w~ ~ 55I 17Ii ~rz,W"
( ..Vn~ SW 1
/ ",:".7,0/":'~~,./_ SE. 'I ~c. 3S- .----"
or"' l,y cl-t '1"'" (...tI." •"o~ , \ Ill" h e""~ ..,t.;••", ,"" _. ' " ..l (I' 'I I~ 1v ls q,,,,
",--",,,,1. t ' 10 SOb
/)
0 Il.OOLf c· I <-f's
\
in 1 l.:so ...\,••••.>. c .• r,T ,,;t .
. _." ' . .: . __ . . _ /':-~'- " "T """,-" ''--~ ~ ~"••• ,-'''1''1Y''~''\ " .' .c' ~,' : .. / - ~ ~ .. ,'~ <'M' ' - ./- ,"'.:-;C____ '.j' .,,',..' ' ~ _' . ... "H" • - , .."......, •~ ~" ~ ~::"I:' " '....7'; _'~"~."~' , ~.\~\ ",,"'" • '" ' ~ .. ".r., ' • M,...s. ' /' "~.l~· '•••".,•.",,'; • " "" ,,' .".i,t. fI-' .... " ~ ~ , ..,:.. / ' ","" ~r."."1.".(\,'" " , /" • .. ~ / ..".< .,,,£
7
'" .' U • / I <0
("l-L," "hI' " •. ~,nn,.,r J/ ~ .. d' .. , - 'r• 'If ,,"".. "' • ,~ ••, I~r T,~ ••ko'-,< po. '1' ,'.U, ,. I
_____.....::c~I"'~,-!.'..~' .:,,~"1 2 ~'I" '\ I""hq , \
~.;.,~j.:~,,"«' _ I .'C, _ 1""" .=.~..'.f ",,:~I.,., r "" 'l ,,-,1<.... I""1..", 3-'",,'"' b ' ~<s,+'".... ;~~~,,,,-~~~~~~t, ~~~~:~.,:: _, I ,,~,...(;:,:~_;,,",~,~~~,..----c, __- ~-' ~:-'-"--" ;:;..--: ../ I \.
',' I' ~ ,,"~"",;/~'0' ;.)' '$;,"'!¥!I!,~tc'-'if' ; < ,-, ,- ,~J"~ :'1/" ,,.,,\,--~-:::;,f!!!;/,,~::::-\: ~ ~ fr<c,.. ",l>r;eot" ",I> ~" <'u,,' ' "-hrow", s\-'.\u] Jt~ 'jr"",k
n. •• ASf",,'1.S ~~ :
I'f/Ar ~ 12,2 !O.2 J'lu<.c... f" 't_ hi b 0 '" ""' 'S •, • "/'p,r- "h I "
("AtA 7~- ~5 ........ - "~,:,~::~: ""' .' T·ll '''',L • 7d"ys -;-d"1'1 :!.-.Its
ow.... - tuFF 1 r.s/ ..r~"H."" 55 --<to S' L 1\ ' <.0"''' I
"C" l'
I00oI
• ll'-
-, . ,
rJtfr~S\"t...t'·H or sL"'''r~l t ... rr,,;,,-, w~tr~\>.>sj" fiJI o:t't4i",s ~/S· ENE. J.;fs.
-81-
-o..• ID
~
......"•"VI...
--~"-
\
I(1I1t.,. N1-Hc.I~ J
VTiN! t S'kf.
~~k
oj. ..
-.( ......~ 'l<
"/..,...
S'1.<:JiOh cllO'tl~
\
N~ (Or"1" He..7TIN, "'lIN.
-.f-- 2. rn,L'l.'!> -..
IcoNI
<D l\...'}''b l .. J con~;~1" of foll..,Lo T'..t.~s. "b"d.di", ,"- 2.1
i~,<.k..l b,~<. <o"~ist of s ....b~, ...:L 4mo....tS of fl"'lJ"~Le.1,.u," L so"J.s, b.r A">' ~w l~ (.0 WI' lO'"'H..t,·<. S'h.JS J 1'0,,,,1" bollr cls.s~mbl"'1~ SJ f Ii t'"<.k oAd,,,i.s flolW JtfOj,"/$ •Colors or, )t1~d. n.l-loroOllls. .I... br;~q""::'1f\- poi ...Ts io .. ~,.J...* 5 ..... cl SW. d;r~ - 30° tow.~oAs "35:-lfS;oE.e.l...sts a,.o. ". .. ~,i'l. s .....a "",J.,sit•.s s."'l." ;... 1h" ·H'l."" r... Lo.o30·'(S J I/p"c./...'l. (sr, de.. JJi! noJ...c1. K...!-brol4l? ,?lo,.s.
Th;<.k l1 ..s.s rttA.y (.(<''l'l.A Soo. from 51;,10, ,.l,p clcif.. , H,n mo.y b'l. ""0·~,s(,orJ.Q"c', i.. ~;P" ...111. u"l.,ll\~l ...n.l.t~lt, ...® An!q"s\1'l flo .....s ) flow ~n.c..e..ia.s, P1 ro c.l... si;c. 14~iI"s, ..... ~ I"H... ~ ...o~ \, ....\s. ,....I~~r ....(1/ bQaal! I wit\.- A;rs
ot 3!;-ljS-°1ow" ...Js }J~S"0£. S..et;...". i.. ''''l'Iu ...L 1'Ie\" .......~\.- Ali,,",.\.., KJAy SQ"'fl~ of '\...,n flow mOlt...,.; .. L..bo.;:t lV WiJ.! "'f th'l s...<.t,c,... fro". th! botfoM.. cl..1ts. ci.t Ittt D.1l ""!. &-~Ls l'"'r0,.D. Ah~t.stt, Sll.c:tloM by rtI"f
i"s,..et;oY\ in rn...in w",,-t... r"l""f l.v"" i~ S"oo- ?,oc;>' thick J "'".- 'f}Ar sa.tafl.. h...s ...t LIl.Ol,T (oo' ..f .....J.~;ttSb",.....t\, iT.
ill An!,,~,t..<. -. ;nt'l:rm~~;;j"," c;;"Jt.r <'0"''- 0"(" <-C)-posit", (.cno.~ ""03u;,,l J ;1'1<.1"";"1 51...,,,,} ; J;votJ b-llls ofrYt'o~l.. ~tl(. \'JI. ...tll.n...Ls. 1 SP~'lY" fLows J "'W'lJ. ..Lo ... , ..."'''' (1'- 3.S' lo", c\,~~..t'l.rj bo I.s. CL,,,,rl, 0", tl.c.
fL..... k..s .f <OWl 1ft1...t'W\~A,,~1q SI),J ",,,,.l.,,sit,·c l1oLc:""",o.
~ .I.. r~"c.~s/ J"Yf01J.'l~')"~ to ~~S'lst of "~o. ..........6.;..t J f,·/"Qf5 .11'"""l-y-r/c fJ .....s (Shu.... ~'yY>ola~J r'~.c....'"~.® S...a-, .... I!> ,nf..r,.~ 10 ~ .. J. ... 'os,t,o....L. "'f'""- lh't 1. ,,"" -·"h. W'<.h"hurj bo\thoLltl.. T~. c.ln\1"...<:1" waS Y>ot
obs."rlJ"J. •
* ilow Ji,...c..iioY\ to """- c;- S w.
/
I
114' 113'3
7' IT T~""""'-'-""""''''''---~-;':;'''''''''''~'l'''''--''-'-''-- -=1:..;I::-2-"·_--="'-"_'-'_"-1"'__......,,;~;......,T"--......'--"'-........~11O'
,,' i rnii' ) !", II , -r III I , j I
i I 0 J 1111. , \.->,
,
Figure 27. Arizona physiographic provinces used in this report.
-83-
50I
oI
boundaries of domains in which pre-13-l0 m.y.old Tertiary sediments and volcanics tend todip variable amounts in a rather uniformdirection.
~~~...... direction of dip within a domain
presently known gneissic-crystalline complexes("metamorphic core complexes")showing trer.ds ofmain anticlinal arches (--4---) and extent ofknown or inferred "dis location surfaces" (~ )(data from S. Reynolds). Likely, archingoccurred 16 to 13-10 m.y. ago following the"dislocation surface" event.
,.1
>
"IIJ I
I
Figure 28. Regional dip directions of pre-13-10 m.y. old Tertiary sediments and volcanics (largearrows) grouped into domains approximated by dashed lines, modified from Rehrig and Heidrick(1976). The domain boundaries may not have changed much during two or three Oligocene-Miocenedeformations, thus indicating a fundamental basement control. Note also a geometric relationshipwithin a domain between the main trend of dip directions and the assymetric distribution ofdislocation surfaces around gneissic-crystalline complexes.
-84.,...
112· 110·----.---
ItI
~.i~Is.
I I
0) 1\11
'-, .....\
..,,A
0( n) I
I
>
fl••• laH•
Figure 29. Prospecting permits issued on State-held lands for the period 1975-1978thought to be for uranium exploration. Data from State of Arizona Land Department.
-85-
NW ColtNfR OF -ST/lTE SE CORN£R OF STJlTE.
s,.I.:....."ts fiLL,'.. , tl. ... h",insCH ...T..~ by 1'1... 6",;" .. nA. R"",-tJ..cr.. r b.. IIe.,-- .
'':2.0~
S....~ .. <tlO'-' -reL...i ..~ ....lc.
oLk .. li .. oll of "i,..''''' b':it~ • uol,....i<:..!Ow11~ .';;ttrc..l ..T..4. r....U,~S.
V.lc.a ..ic.s co .. ,·,~-r .f .....l.. ;it'lS• J
rloyoL\tt ''l ..; ...br it.... , hi, .. -I( -r.....,,"yTuJl ...ti-td.
~rr~-(a...~ $l h j uolc.. "·,, f,b .....cl.
<o..rs.~ 1r"·' .l, TiLt.cl J Thic.k<:I ..slic s'o\ <.~ I c...t · i..~ r.~ ...Il~si.. rl .. c~s. \!oL" ....ic.s ..
s .. c. ... l ...rJ i.. ·....for-r.... <.'1 i.. 11.,,$'~" ",."",$.
~-------
H--.ChUo<..o....,. flow
~A~
_~IO~
s=i':;~.,.1 ,<:~"'rlu .u..... 61c.,~ cS" b..·,t... rJr..c.l..~Ti<." tL.ic.k.,.l of <.0 , .. c.L""T,c., l'''f.."t.. ~i-. ""t..cio .... i, \, sins j rift-rlllCLtlla IoAS4Lts
J..l.r Dsit..A in ClM.\fl.& rMt ~ st...tt.
(01.=-~---
F,L L' ....
'-1' ~ s .... t,',,~ ~ · ......,tr. t.~~ f,,, ..<...1.. b•••\1...>v.-;... .?-r....To B.o;n b:;J
.5 l.k,...11~ -
""-10",.
* ~noll\..lo"$ r..~ioo.c:liuit1 or
~o
tV(.
~ 10voa-
-Jo
~
LQl. ti'ltQ4 P4rhr 1.......'" fho~njx ""Tuc~on CJ,jr/,,,h.. ,,,,~ + + ~ ~~
~ e...... -, _. P L Co's T .. Co ~ .... Co J. e e" ;5 ,. 7 s ~ rJ",stoc..." ... f ...... ,.J Tu.... c... d..,oS";tc."'.___ _ .~ ~$r.D._i~Jf.tL ----------~ ~<.~~~ __ Ad'" ,~ .~~
. - S.4h~Y Po;,)' B r-~ b.sfflt.., OI4~C. n~.
~ l'IllWllmil!.- * t.,Fo.T; f"4t'-O" bco ,.U t-"
C'.1Ta"'Woo4 bo.~.. [jSfr:u=t::>+- H••L- r.i Ls
Gl 10
s:.aI<J0
I --00 ~0'\I
;to
~
fl',,,,r ~ 30. S~C..-Iilll~ fr."M Qf A.r;3ot1G1. ~"jl1 f R4J1''t (C.no3"ic a"po,jf"£ f"Oj ..;.(~to l). ltllti41. NIII-Sf. Cross - s~ct/C»1 Lint.
35'
3-4'
Figure 31. Generalized" floor" of Cenozoic deposits in Arizona.
-87-
I
-J
)
(I
d) I
.. I
)
"d
I
-.l
alkali-calcic 30-13 m. y.volcanics (source: S. Keith)
alkali-calcic Jurassic (200-150 my)plutonic and volcanic rocks(source: S. Keith)
alkali and alkali-calcic Precambrian(1500-1300 my) granitic rocks(source: P. Anderson, U of ArIz PhDthesis, in progress, 1979)
polt~.
~~~~t-+--+--~_~
O'e 1 A.I <y
,I,------.::"lr.-r-~_r_-.----_r-r_----
1\
<'.. '..... -
114' _ !]3'n'li -- ,
;1'IIi
36'
e
"1\
(urn.
Figure 32. Presently known outcrops of alkaline rocks which might have servedas sources of uranium for Tertiary sediments.
-88-
<
(J
)
I'II
) I
( I
< J~, ;.-
I ..-!'/I 1"'/ L
-,
~~iSa":d -)\\!
) I
l, I-----------~i,
1
i OJ
i III I, ..J
! ~I (OJ I
~ "1,".n~..-
)
>
o
III!
p
A
"...."....L50 0 50 MILESLI.-.J'---~--J.._~--LI- --.JI
36' / '--\. I
\;;-~~~-:~-::-:--.::+---r--~---.J::=:::_~--£.=--_-t-_L-,i./~_~~ ~-.o=.-.!"i i, X
COl) C 0 i N
'\ /: IMo1olLon- j
~FI4L~RiW\ ,\III
Figure 33. Generalized sediment transport directions of Oligocene and earlier iVIiocenefluvial sediments in Arizona's Basin and Range province. Data comes from pebbleimbrication and cross-bed directions. 0 = Oligocene aged; M = Miocene aged; r =mostly red-colored sediments. Large hollow arrows are generalized from the specificlocalities. The Mogollon Rim of today is a paleo-feature probably present in Oligocenetime and therefore was a northward limit to Oligocene deposits.
-89-
[
0-4 m.y. "\
~ 4-8m.y.~
8-15 m.y.
AMuy
)
,II
-I'-_----~,....JI ,
I \ !36"~:'r~~-':;~-7.l+~.t--~_..-:...=t:::=-~.:!~=--·-_-_·il-.)j!_1
Figure 34. Generalized outcrop map of post-15 m. y. old volcanic fields in Arizona.In places these rocks may be covering and preserving uranium-bearing mid-Tertiary
sediments. Sources include Eberly and Stanley, (1978); Luedike and Smith (1978).
-90-
TABLE 1. URANIUM LOCALITIES IN PRE-BASIN FILL TERTIAHY SJ::DIMENTS IN THE BASIN AND RANGE PROVINC!:. UF AHIZONA
(.) denotes areas vIsited and geologically updated. Otherwise, data comes from rderences.(•• ) See listing at end of table for visited loealittes eontatntng other than Tertiary sedimentary host rocks.(+) All measurmcnts for thIs report were made with a Geometries model GH-lOlA stngk channel gamma ray sdntl1lometcr.
I100l-'I
Locality
MOHAVE COUNTY
Big Sandy Valley*Catherine & Michael
Claim5Ek 535, l7N, l2W
Artillery PeaksArea*Lucky FourNE~ 536, l2N, l3W
*Masterson GroupCenter 522, 12N, 13W
Candy Bar GroupN!:i 12N, 13W
Number onIndex Map,Figure B
4
2
Cross-SectionFig. No. (SeeFig. A forLocations)
24, 25
19
18
Host RockCharacteristics
Tilted blocks of fine grainedclastics, depositional on p€granite and tilted by high anglefaults. Minor tuff beds and basalt flows in the section.
Five foot thick carbonaceous bedand several thick-bedded limestone beds in a thick, tiltedfluviolacustrine section of theArtillery Fm., probably 1-2000ft. above base of section.
In tilted section of ArtilleryFm.-depositional on Precambriangranite. Probably 2-400 ft.above base of section.
In Artillery Fm., as above;underlain by red arkosic conglomerate; overlain by red volcanicflow.
Uranium MineralizationAssociated Hinerals
Anomalous Radioactivity
Counts in limestones withchert nodules and stringers;and in gypsiferous mudstones.PRR reports uraniferous opal.
Counts in light-colored limestone beds and gray mudstones.Chert locally abundant. PRRreports tyuyamunite and carnotite.
Counts in laminar bedded darkcolored shale-mudstone-limestone sequence just above basal conglomerate of ArtilleryFm.
3-5 ft. beds of mudstone andss.
Radio3Ctivity andBackground. Decimalnumbers are ~ eU 30S2x ~ 2 times bkg.
5x(.013)
5x(.02)
lOx(. OS)
45x(.07)
References (G&RGranger and Raup.
(1962); Keith Keith, (1970)
i PIR (illegible)G&R p. 16-18lCeith, 5-27This report
PRR-A-82Keith, 5-29Tbis report
PRR-A-68le1tb 5-30Finch (1967)This report
PRR-A-SllCeitb 5-28
Navico GroupUl (see PRR)
Red Hills (Tate)~ 57, llN, 13W
5
6
In unnamed sediments, irregularlenticular beds of arkose, ash,sand, mud, with basalt cappingon ridges to the south.
Radioactive zones in a fault orsedimentary breccia at or nearbase of Artillery Formation,where it is in low angle faultcontact with crystalline rocks.
Carnotite as fracture coatings.Silicified wood present.
Counts concentrated in fractures and/or shear zone intersection with veins; origin believed due to groundwater.Accessory CUO, chalcedony,flourite, Manganese oxides.
7x
.06 avg
.31 sel
,; PRR-A-83-~7i
PRR-l92!:e1th-5-31Hart (1955)Lasky & lIebber(1949); G&R p. 22Finch (1967)Puch11k and others,(1979)
TABLE 1 (-<:o~inu.,d}
Locality
YUMA COUNTY
Alamo AreaLincoln Ranch Basin
Number onIndex Map,Figure B
9
Cross-SectionFig. No. (SeeFig. A forLocations)
Host RockCharacteristics
Mn-bearing redbeds with low energy rocks; silicified plantremains. Tuffaceous sltst andmdst beds present. Redbeds arein footwall of Lincoln Ranchthrust fault and are allochthonous above older crystalline rocksof the Buckskin Mtns.
Uranium MineralizationAssocIated Minerais
Anomalous Radioactivity
Uranium as carnotite in fractures and as uraniferous silica in bedded chert.
Radioactivity andBackground. Decimalnumbers are % eU308
2x - 2 times bkg.
Reference (G&RGranger and Raup,
(1962); Keith Keith, (1970)
Wilson (1962)Gassaway (1972)Otton (1978)
I\DNI
Bouse Area*RayvernN~ 513, 6N, l8W~ 57, 6N, l7W
Bouse AreaLillian #1, 2, 3of Starlight Gp.(Location uncertain, but probably in N. PlomosaMtns. )
Yuma AreaMuggins Mtns.Dizzy Lizy510, 7 or 85, l8W
Wooley Gp.532, 75, l8W (Keith)56, 85, l8W (otherrpts)
Lake Bed Claim52 or 7, 85, 19W
Red Knob Claim510, 85, 19W
7
8
10
11
12
13
5 In a thick SW dipping Tertiarysection on the east flank ofPlomos~ Mtns. Sequence complexlyfaulted, contains rhyolite flows,gy Is beds, arkosic conglomerates,green sh beds, and andesite flowsforming resistant ridges.
Remnants of ls beds, in countryrock of older granite, schist,and related x'tline rocks. Recent volcanics and sedimentspresent.
4 ft. tuffaceous bed in dippingsedimentary and volcanic series.
Brown water-lain 5S and mdst withbasic volcanic sills or flows.Sediments dip 25-30oSW.
Volcanic tuffs overlain by 55.
Fault between rhyolite and lakebed sediments.
Section consists of highly silicifi~d or porc~llanized mdst,Lake bed sequences, ss, andsome volcanics, apparentlytilted.
Carnotite fracture coatings inwhite colored limey shales sandwiched in a thick gy coloredlimestone sequence; invisibleminerals in a fault zone betweenarkosic conglomerates and ~ndesi
tic volcanics.
Cu, barite, Mn, Au, Ag noted inthe area.
Unidentified uranium mineralization.
Uranophane, autinite in hematitestained sediments close to a probable basic volcanic sill. Somequartz stringers are highly radioactive.
Uranophane, pryomorphite (?) andchalcedony.
Uranophane, carnotite or tyuyaminite, weeksite; with strongchalcedony or opal, gypsum, darkcalcite. Mineralization in mdst,bu~ localized near a N30W trending fault.
l5x(.03-.08)
2x
25x(.08)
l25x(.175)
(0.2-0.7)
30x
5x avg100x max
·PRR-A-P-348Keith, V-80Jemmert (1966)This report
PRR-A-P-230
PRR-A-46Kaith, 5-34
PRR-A-P-300Keith, 5-35
PRR-A-P-34
PRR-A-P-302Keith, 5-37
TABLE 1 (continued)
Chalcedonic white ash bedscount. Gypsum and opalinematerial also noted.
Locality
Isley-LillardS6, 7, 8S, lSWSl, 12, 8S, 19W
Number onIndex Map,Figure B
14
Cross-Sect ionFig. No. (SeeFig. A forLocations)
Host RockCharacteristics
Synclinal structure developed inTertiary lake bed sequence, consisting of upper gy sandy sh, redss, lower gy sh with white ashbeds. Overlain to the west by obsidian flow and rhyolite (?) flows.These sediments are downslope fromthe Wooley Claims.
Uranium MineralizationAssociated Minerals
Anomalous Radioactivity
Radioactivity andBackground. Decimalnumbers are % eU308
2x - 2 times bkg.
6x
Reference (G&RGranger and Raup,
(1962); Keith·Keith, (1970)
PRR-A-P-389Keith, 5-38
I\0WI
St. Louis Gp.S2, SS, 19W orS35, 7S, 19W~(they lie to NWof Wooley Gp.)
Bonnie,. Marvin.Jap, William,Edward,. HWWR."B" ill, 2, 3.S2, 12, 8S, 19W
Laguna Mountains*Adair Park
BedsSW!,; 7S, 21W
YAVAPAI COUNTY
Date Creek AreaRiverside #1S9, lIN, lOW
Uranium Aire Gp.(Anderson Mine)S9-16, lIN, lOW
Lower Verde RiverChalk Mtn. area340 02'N 1110
42.5'W '(unsurveyed)
15
16
35
17
18
37
4
22
Tertiary sh, ss, and white ashbeds. Basaltic and rhyolitic intrusives. This section capped by"Gila" type cong. with schistboulders.
Gray shale in Tertiary sedimentary series of sh, ss, whiteash beds. Basalt and rhyoliteintrusives capped by persistent"Glia" type cong.
SW dipping redbed section, inhigh angle fault contact withMesozoic (1) gneiss, and overlain by Kinter Pm. fanglomerates. Apparently consists oflower 5s-cong. and upper mudflows and breccias.
Gently dipping Tertiary lakebeds and tuffs. Uraniferouszone is lignitic or carbonaceous mdst, and is overlain bycongo and a basalt. Tertiaryvolcanics underlie the ore zone.
flat-lying section of tuffs,fine-grained sediments. andlimestones very similar in general character to the tuffaceous s~ction at Horseshoe Darn.
One dozer cut contains youngsoil, Pleistocene gravel veneers, and tilted green Tertiary mdst, all with disseminated uranophane (?).
Counts in folded and faultedchalcedonic shaley mdst beds.Uranophane (?) noted.
Counts in lower yellow andbrown mottled shale - ss sequence near high angle faultcontact with Mesozoic (?)gneiss.
Ore zone 1s associated withchalcedonic materials, ligniticunits and abundant plant debris(carbonized); carnotite and uranophane (?) are associated withjasper; urano-silica complexes
'are found 1n carbonaceous beds.
Carnotite as fracture coatingin certain units low in thesec~lon.
115x(.03)(select 1. 7)
7x(.05-.24)
3x
(.08)
5-160x(.07-.60)
3x ?
PRR-A-P-390Keith, S-39
PRR-A-P-391Keith, S-40
This report
PRR-A-1l7Finch (1967)
PRR-A-P-394Keith, S-33Otton (1977) And(1978). AGS Springfield trip, 1978
This report
TABLE 1 (continued)
Locality
*Lake PleasantN~ SID, n;, IIE!:i 522, 7N, lE
MARICOPA COUNTY
Number onIndex ~1.1.p,
Figure Il
38
Cross-SectionFig. No. (SeeFig. A forLocations)
23
Host RockCl1ar~c tc rist ic 5
Gently warped and folded lightcolored sequence of tuffaceousbeds and lacustrine Is yith ~inor
sh, depositional on order tuffbasalt sequence and overlain byundeformed low energy beds whichare probably basin fill materials.
Uranium MineralizationAssociated Mjncrals
Anomalous Radioactivity
Carnotite as fracture coatings and invisible disseminated mineralization localized in certain clastic andtuffaceous beds in the sequence. Both the overlyingbasin fill (1) and the tuffIs sequence have been explored by drilling.
Radioactivity andBackground. Decimalnumbers are % eU308
2x - 2 times bkg.
3x
Reference (G\R~
Granger and ~~up.
(1962); Keith·Keith, (1 ~70)
This report
I\0-l:'I
Western Vulture Mtns.Milton Ray GroupS2l, 22, 6N, 7W
*Jar Claim, BlackButte Uran. Corp.
SEI( 514, and SWl(513, 6N, 8W
Black Mtn. Gp.514 (1), 6N, 7W
New River Area*Los CuatrosS32, 7N, 3E
*Cave Creek AreaS~ Nil!,; S15, 6N, 4E
20
21
19
23
42
14
16
Tertiary section depositional onleucogranite to the east, andtilted to SW, including lower arkosic conglomerate and andesiteflows, middle fine grained clastics and tuffs, and capping basalt-sediment series.
100 ft. bed of shaley marl.un~
derlain by Precambrian metamor.phics, overlain by thin basaltflow.
Area of low-relief pediment cuton Tertiary sediments and volcanics, overlain by young gravelcaps. Tertiary section consistsof buff mdst, bedded dolomites,thin tuff beds, and intercalatedbasalts. The section is downfaulted against Yavapai schistto the north.
Area along Willow Springs Washcontains a section of low-energysediments containing mudstone,limey and sparce dolomitic beds,2 thin vitaic ash beds, all dipping 30-50 SW, and overlain bya conglomerate with clasts ofPrecambrian schist and Tertiaryvolcanics.
Carnotite as fracture coatingsin mdst-vitric tuff section;confined to thin zone withinotherwise homogeneous 20 ft.thick buff mdst section. Uranium probably out of equilibrium since low count rate isassociated with abundant carnotite.
Carnotite, gypsum, iron andmanganese oxides, with carnotite coating fracture surfacesin marls.
Mineralization is invisible,and concentrated within 1-3 ft.beds of resistant ledge-forminglight colored aphanitic dolomite beds. One thin vitrie ashbed intercalated into dolomitesis not devitrified.
Radioactivity associated withsiliceous stringers and veinlets,and also a few thin limey and uncommon dolomitic beds. No visible uranium mineralization.
3x7x
(.01 max)
(weak)
3x20x max
(.03-.06)
to 7x
Hewett (1925)PRR-A-P-83PRR-A-P-342PRR-A-P-343G&R, p. 15-.Keith, S-42Finch (l967)This report
PRR-189
PRR-A-76Keith, S-43Finch (1967)This report
Tbis report
("
TAflLE ] (c(lntinll~d)
Locality
Pheon 1x Area*Rifle Range Section53, 4, 5N, 2E ~nd
533, 34, 6N, 2E
Number onIndex Hap,fiGure B
43
Cross-SectionFig. No. (SeeFig. II forLocations)
17
Host RodCh:1TGCt eri st ics
Isolated hill at 1-17 and Carefree Highway consisting of northward dipping section of lower arkosic sediments overlain by 2lithologically distinct whitedolomite beds containing diagenetic silica replacements and anunconformably capping dark volcanic section.
tJr.'lnil1m Minf".T<Jljz.:ltionA~""":i~tPd t'incr~ls
Annri:l;nu~ R~dlo~ctivity
Some radioactivity associatedwith chert pods, stringers inthe 2 dolQmite beds. Lower,more ch~rty do)om1te counts to250 cps. No visible uraniumminerals.
R~dio~ctivity andB~cy.r,round. Decimalnumbers are % eU
30S2x • 2 times bkg.
to 3x
Reference (G&R'Granger and r~up,
(1962); Keith·Keith, (1970)
This report
Carbonaceous sh along iron stained Mineralization controlledfault with Is on footwall, schist by complex faulting and brecciaon hanging wall. Bedso(of Mine- tion. No visible minerals.ta Pm?) strike N 45-60 W, steepdips, and include quartzite,phyllite, congo
I\DVII
Gila Bend ~Itns.
*Duke, White,Hyder Claims
*531, 25, 9W or536, 2S, lOW
Lower Verde River*Horseshoe Damcentered at 330
58.5'N, 1110 44'W(unsurveyed)
PIMA COUNTY
Redington Pass,Rincon Mtns.*Chance Group~ 510, 135, l8E
*Van HillD7 and 8NW\ 524, 135, l8E
Roble SpringSill,; 530, US, 19E
25
39
28
26
27
6
22
I, 2
I, 2
Section of Tertiary rocks tiltedNE, in downthrown tilted faultblock; in depositional and faultcontact with gneissic-crystallinerocks. Section includes arkosiccong, ss, mdst, one welded tuff,and thin-bedded Is.
SW dipping section of basaltsoverlain by a white colored tuffmdst-ls sequence, in high anglefault contact to the west withPrecambrian granite and to thesouth with younger flat lyingbasalt-capped sediments. (seealso Chalk Mtn. locality)
Oligocene section tilted 30_600
NE, in fault and depositionalcontact to west with Precambrianand Paleozoic rocks, and in faultcontact to the east with youngerfanglomeratesa Section includescong, Is beds, mdst, gypsiferousmdst. Section unconformably overlain by late Oligocene andesites.
2x radioactivity in slightlyfetid, thin bedded gy Is bedsintercalated into an arkosicss port of the section.
Counts concentrated in a few 1sbeds in the sequence, and in silicified zones near the high anglefaults. Silicification in areasis intense.
Counts in dark-colored sh lensesintercalated into basal red congof Mineta beds, and elsewhere inIs beds and overlying limey shalebeds. No visible minerals noted.
to 4x(.01)
5x
100x max
35x4x
(. 01-. 02)
(. 004)
PRR-A-P-382Keith, 5-44This report
This report
Bissett (195g) p.37Chew (1952)Clay (1970)G&R, p. 36Keith, V-39
PRR-no numberBissett (1958) p.37Keith, V-39Grimm (1978)
PRR-629 (?)G&R, p. 4Keith, v-66Bissett. (1958)p. 48-
TABLE 1 (continued)
II.D0\I
Locality
Rincon Mens.Colossal CaveArea*Red Hills claimsNE~ 56, 165, l7E
Southern TucsonMens.*Dutchess Claim517, 155, l3E
SANTA CRUZ COUNTY
Duranium520, 205, l3E(PRR)S~~ 520, 20S, l4E(Keith)
Santa Clara ClaimS3l, 22S, llE(PRi.)N~ S6, 23S,·11E(Keith)
COCHISE COUNTY
Number onIndex Hap,Figure B
29
30
31
J3
Cross-SectionFig. No. (SeeFig. A forLocations)
1
1
Host RockCharacteristics
Prospect pits in Precambriangranite, and Tertiary clastics(Pantano or Rillito beds) st different pl;ces. Terrain consistsof juxtaposed high angle faultblocks containing either HartinFm, pE granite with Pioneer Shale(?) veneers, or Tertiary clastics.
20 ft. thick section consistingof beds of fetid light gray limestone 2-3 ft. thick with lesseramounts of gyps1ferous mudstoneand gypsum seams". exposed in twodozer cuts. Sequence is foldedinto a shallow E-II" trending syn~
cline.
Altered arkosic 55 within cong.possibly at the base ot Cretaceous or in Tertiagy deposit.Strike E-~, dip 45 S.
Steeply dipping ss and cong,mapped as Cretaceous on StateGeologic Hap, perhaps Tertiaryaged.
Uranium MineralizationAssociated Minerais
Anomalous Radioactivity
Counts in some fine-grainedclastics of various colorswith no Is or 59 present atone area, in weathered redbrown granite near high anglefaults in anot~area.
Mineralization disseminatedin fetid limestones, withsome carnotite fracture coatings in a few areas.
Kaolinite, uranophane, autinite noted. Rocks are faultedand altered.
Sooty uraninite in highlyfractured and faulted rocks.
Radioactivity andBackground. Decimalnumbers are % eUJ08
2x • 2 times bkg.
3x5x
(.08-.38
7x max(0.6)
190x(.05-.B)(2.J select)
105x(.02-.15)
Reference (G&RGranger and Raup,
(1962); Keith·Keith, (1970)
PRR-A-P-3l4Keith, 5-54Drewes (1978)USGS Hap 1-997This report
PRR-A-65Keith-S-53Grimm (197B)
PRR-A-P-285Keith, S-55
. PRR-A-P-293Keith, 5-56
Southern Galiuro Mtns.*Teran Basin Sequence~ 522, l3S, 20E~ 526, 135, 20E
41 1,3 Thick steeply eastward dippingcoarse and fine grained ~edi
mentary section with cons, ss,mdst, &y?s1fe~ous mdst, andsome Is. Overlain unconformablyby Oligocene Galiuro volcanics.
Anomalous radioactivity inyellow and red-brown mottledgypsiferous mudstones high inthe basal half of rh~ TeranBasin sequence. Slightlyfetid limestone beds did notcount.
3x This report
TABLE 1 (continued)
LocalityNumber onIndex Map,Figure B
Cross-SectionFig. No. (SeeFig. A forLocations)
Host RockCharacteristics
Uranium MineralizationAssociated Minerals
Anomalous Radioactivity
Radioactivity andBackground. Decimalnumbers are % eU30S2x • 2 times bkg.
Reference (G&RGranger and Raup,
(1962); Keith·Keith, (1970)
YUMA COUNTY
**The following localities that were visited contained other than Tertiary clastic sedimentary host' rocks.
I\0'-II
Parker Area*Osborne Wash\J!, S 4 (proj ected)9N, 17W
COCHISE COUNTY
Pearce Area*Elanna ClaimsSW~ S35, 17S. 25E
Johnny Lyon Hills*Inez Ellen ClaimsNE\ S~ SB. 14S, 21E
Chiricahua Mtns.*Swisshelm Valley~ 20S. 2SE
MARICOPA COUNTY
Wickenburg Area*Golden Duck Gp.S19. 20. 7N. 2W
36
34
32
40
24
13 Tertiary Is in low angle fault contact with gneissic lineated crystalline rocks. Limestones arerecrystallized, and devoid of mineralization.
Silicified limey shale near contact with vole. agglomerate.
Locality is on a west-facingscarp of ease-dipping Paleozoicsediments. The entire BolsaHorquil1a section is present;an anomalous shear zone appearsconfined at the surface to theMartin Fm-Percha Fm interval.Precambrian granite under theBalsa is several hundred yardswest. No Cretaceous sedimentsare present as noted in the PRR.
Section of Chiricahua-type rhyolite welded and unwelded ashflows and possible thick ashfalls, underlying a young pediment surface which is dissected by recent streams. Crossfaults complicate the stratigraphy.
Tertiary rhyolitic domes, plugs,and pyroclastic tuffs in faultcontact with Precamorian rocks,overlain by young terrace deposits, which were misidentified asba~al arkose in the PRR report.
Counts in limonite-alteredx11ine rocks just beneath alow angle fault with Te~tiary
Is above. Associated withcopper-iron-Mn (?) mineralization.
Silicified shear zone associated with low angle fault andgouge. No visible mineralsnoted. Rhyolites flows nearby count high compared to average rhyolites.
Anomalous radioactivity in oneor more dark red-brown coloredshear zones cutting across bedding. Recent exploration includes new dozer roads and cutsand at least 20 drill holes onhillside.
Counts appear disseminatedthrough friable white alteredair-fall pumiceous devitrifiedtuffs and tuffaceous sediments.
Visible torbernite with minorcopper and iron mineralizationas fracture coatings and faultgouge mineralization. Somehydrothermal silica open spacefillings in certaln rhyolites.
3x
20x(.20 select)
to 5x{.19-.26}
2:<
to 60x(0.2-0.6)
This report
PRR-A-P-335Keith, v-76See also G&R, p.3for nearby FluorineHill deposit.
PRR-A-113Keith, S-57This report
This report
PRR-A-77Keith, S-41Finch (1967)This report
Table 2.
Univeraity of ArizonaIsotope Geochemistry LabDate: 1 June 1979
Potassium-argon determinations.
Constsnts used: -10 -1~8 • 4.963 x 10_10 yr_l~~ • 0.581 x 10.10 yr_1
40 A· 5.544 x 10_4 yrK/K • 1.167 x 10 atom/atom
SalllpleNo.
76-96
76-133
76-133
76-133
77-70
UAKA77-106
UAKA77-108
78-30
Sample description and location
Whole rock, andesite, base of massive flow, 'middle section of the andesite unit that overliesthe Apsey conglomerate of M. Krieger. The conglomerate overlies Hell's Half Acre tuff and Aravaipatuff in the northern Galiuro Mountains. TableMountain, Holy Joe Peak quad., Pinal Co., Ariz.Lat 320 49.74' N, Long 1100 31.26' W(RS-11-76).
Biotite, airfall silic ash, Jim Thomas Wash.Sample, from a 2 01 thick white ash bed intercalatedinto the San Manuel fm. of M. Kreiger. The area isstructurally complex. The sediments are synclinallyfolded. A high-angle fault brings overturnedPaleozoic sediments and Cretaceous (1) volcanics intocontact with the overturned San Manuel fm. west ofthe sample site. Cozier Peak quad., Pinal Co.,Lat 320 5B.75' N, Long 1100 .56.71 W.
Hornblende, same as above.
Plagioclase feldspar, same sample as above.Plagioclase contains excess argon-40.
Whole rock, basalt flow about 3 m,thick overlyingcoarse grained sediments and uranium bearingdeformed lake beds containing lignitic units. Thelake beds range between 30-60 m in thickness, havea 100 + dip south and are faulted. The overlyingcoarse grained sediments are about 76 m thick.Elevation 606 m, sampled at outcrop along tributaryto Santa Maria River, Arrastra Mtn. SE quad., YavapaiCo., Ariz. Lat 340 18' 11" N, Long 1130 16' 37" W.
Whole rock, basalt. dark grey. fine-grained groundmass with abundant olivine. about 10 meters abovethe first exposure of a series of flows that capSkull Mesa. Basal contact with the underlyingtuff sequence is concealed by 40 meters of talus.The flow presumably correlates with the flows onBlack Mesa, Sugarloaf Mesa (UAKA-78-36) and flewRiver'Mesa. New River Mesa quad .• Maricopa Co.Lat 33 0 55.42' N, Long 111 0 55.18' W.
Whole rock, basalt. approx. 7 meters above unconformable contact between basalt and lithic tUff. Basalportions of flow very "crumbly", well fractured andweathered. Fractures are filled with abundantcarbonate material. The underlying 1ithic tuff sequence is fine- to medium-grained with nranules ofsiliceous volcanic rock. The sample cOITelates withPEO-5-70 (23.2 + 2.6 m.y.). olivine basalt thatoverlies Oreodont mammal site at Cave Creek. about5' above the contact. Cave Creek. New River Mesaquad., Maricopa Co., elev. 731 m. Lat 33 0 53.81' N,Long 111 0 57.21' W(OL 1.4).Whole rock, u1trapotassic trachyte separating lowerthin clastic section composed of arkosic conglomeratefrom overlying lithic tuff, shale, sandstone andvolcanic breccia. The lower arkosic conglomerateappears' .to be deposi tional on Precambrian (1) basementrocks. The sequence dips 120 to 650 with the steeperdip closer to the Harcuva Htns. Rudy Pass area,Oate Creek Ranch SW quad., Yavapai Co. (NfIVKA-78-1)340 02.35' N, 1130 9.60' W.
-98-
IndividualKanalyaea
1.7B51.7981.781
6.2386.176
0.5660.568
0.7860.779
1.1241.122
0.4310.4310.4350.4350.4300.434
0.6550.6550.652
7.9457.8797.854
PercentKused
1.788
6.207
0.567
0.782
1.123
0.433
0.654
7.892
Radiogenicargon-40x 10-12mole/g
69.6671.9671.56
210.96213.82220.35225.24
23.2323.2322.92
34.9834.98
25.7025.7125.90
11 .16
248.71240.88240.82
239.63238.56238.18237.68
Percentatmosphericargon-40
12.011,611;8
57.556.955.957.6
52.752.754.1
24.023.9
37.8837.5938.02
84.1
30.5131.3031.47
12.512.412.312.5
Age inmillionyean
22.78 t 0.48
20.11 t 0.47
23.4 0.6
25.6 ± 0.6
13.19 ±0.29
14.81 + 0.79
21.34~0.46
17.35 t 0.36
Table 2. (continued)
Univeraity of ArizonaIsotope Geochemistry LabDate: 1 June 1979
Constants used: -10 -1AS • 4.963 x 10_10 yr_1Ap • 0.581 x 10_10 yr_1
40 A· 5.544 x 10_4 yrK/K • 1.167 x 10 atom/atom
SampleNo. Sample description and location
IndividualKanalyses
PercentKused
Radiogenicargon-40x 10-12mole/s
Percentatmosphericargon-40
Age inmillionyears
. 78-31 Whole rock, basalt flow overlying thin bedded, 1.102partly calcareous, uranium-bearing siltstone- 1.109claystone and lower volcanics which contain UAKA78-48. This flow dips 100 SW, underlying sediments an&volcanics dip 20-400 SW. Black 8utte, Aguila quad., Maricopa Co., T6N, R7, S19. Lat. 330 50.76'. Long 113001.87'. . .
1.105 29.7830.32
31.830.9
15.62 t 0.35
UAKA78-32
UAKA78-33
UAKA78-34
UAKA78-35
UAKA78-36
UAKA78-38
UAKA78-39
Whole rock basal tic andesite, underlying the typeGila Conglomerate, merges with a thick ·volcanicsequence to the south, Lower Bonita Creek, r.uthrie q.,Graham Co., elav. 3170', Lat 320 53.21' N.Long. 1090 ·29.84'. W(RS-l-77). .
Whole rock, rhyolite, 50-100' thick, fromMineta Fm. The rhyolite is in fault contact withPinal schist to the west and has probable depositional contact with overlying grey conglomerate of theMineta Fm to the east. Redington Pass, Redingtonquad •• Pima Co •• elev. 3750, Lat 320 17.10' N, Long1100 27.28' W(RS-1-78).
Whole rock. basaltic andesite, grey-black flow,approx. 80' above base of hill on west Tempe Butte.It overlies fine-grained red-brown sediments whichare presumably part of Papago Park fm. Playa-typemud cracks in the sediments indicate the sectionis not overturned. Tempe Butte, Tempe quad.,Maricopa Co •• elev. 1300'. Lat 330 25.68' N.Long 111 0 56.04' W(RS-2-78).
Whole rock. basalt flow intercalated into pre-basinfill fanglomerate sequence. The seqUence dips4_80 towards NE, is truncated eastwardly by the"fault scarp" of the NE Swisshelm area, and truncatedwestwardly by a high-angle Basin and Range fault.Swisshelm Mtns. quad •• Cochise Co., elev. 50BO'.Lat 310 44.25' N, Long 1090 30.63' W(RS-4-78).
Whole rock, basalt, 30-50', below the top ofSugarloaf l1esa. About a dozen flows cap the mesaand overlie a basalt-tuff sequence. SugarloafMesa is south of Hew River Mesa. The sequence isonly slightly tilted to the south. About 10% maficminerals removed before analysis. New RiverMesa quad., Maricopa Co., Lat 330 54.72' N. Long 112057.78' W.
Whole rock, basalt, from a volcanic-sedimentarysequence exposed at Horseshoe Dam area. Sequence(>2000' thick) is tilted SWat 10-200 and is infault contact with younger basin fill mudstone tothe SW. This basalt flow series is overlain bybasalt cobble conglomerates and a higher sequenceof white tuffs and marls. The tuffs containnumerous shows of uranium mineralization. HorseshoeDam quad., 11aricopa Co., elev. 2020'. Lat 330 58.87N, Long 111 0 42.70' W(RS-ll~78).
Whole rock, rhyolite (1) trachyte (1) local basalflow, part of an older volcanic series which restson.Yavapai argillites. It is uncomformably overlainby the basalt-tuff conglomerate sediment series thatcomposes the mesas of the area. Eberly and Stanley(sample #63) dated a basalt flow of the youngerbasalt-tuff-conglomerate series at 20 m.y. Samplecollected from basal andesite exposed at Tu1e Creeknorth end of Lake Pleasant, New River quad., YavapaiCo., e1ev. 1720', Lat 330 58.08 N. Long 1120 14.53' W(RS-6-78) •
-99-
3.2423.193:1.202
3.7363.7343.721
2.481.2.4242.431
1.3501.3661.357
0.7870.7830.7790.7790.7790.778'
0.537'0.5350.536
6.4036.4086.371
. 3.212
3.730
2.446
1.358
0.781
0.536
6.394
111. 34115.70116.54115.85116.69116.99
163.89163.82162.72
.74.5874.9474.85
25.3926.1026.79
20.0819.9319.83
13.4513.5214.02
286.37290.41310.37
8.866.85
. 6.737.12.7.026.95
40.641.238.8
22.5922.4622.65
62.6061.8760.41
75.078.075.3
62.0861. 7660.89
16.6416.3915.50
20.62 t 0.42
25.10 t 0.55
17.56tO.37
11.05tO.28
14.67 t 0.35
14.64 ± 0.37
26.48 ± 0.56
Table 2. (continued)
University of ArizonaIsotope Geochemistry LabDate: 1 June 1979
Constants used: -10 -1Ap • 4.963 X 1°.10 yr_1A • 0.581 x 10_10 yr_1
40 X. 5.544 x 10-4 yrK/K· 1.167,x 10 atom/ato~
SacpleNo. Sample description and location
IndividualKanalyses
PercentKused
Radiogenicargon-40x 10-12molelg
Percentatmosphericargon-40
Age inmillionyears
UAKA713-40 Whole rock, basaltic andesite; flow is one of many
exposed along dirt road around west side of LakePleasant, and is interbedded into a tuffaceoussediment and.volcanic conglomerate sequence whichis tilted eastward 10-300• West edge Lake Pleasant,Governor's Peak quad., Yavapai'Co., elev. 16130',Lat 330 53.78' N, Long 1120 17.97' W(RS-7-7B).
1.8581.8581.1353
1.856 53.3754.18
14.5614.39
16.63 t 0.35
UAKA78-41
UAKA78-42
Whole rock, basaltic andesite, lowest flow that overlies about 5000' thick red clastic sequence (TeranBasin sequence). The'andesite is cut by Turkey Trackdikes and vents. Teran Basin, Galiuro Mtns.,Redington quad., Cochise Co., elev. 3U50', Lat 32017.07' N, Long 1100 16.40' W(RS-12-7B).Whole rock, basaltic andesite in a volcano-clasticsequence homoclinally dipping NE approx. 200• Theandesite appears to be in the same tectonic assemblage as uranium-bearing tuffs, siltsones, andclastics two miles to the north near -the locality of70-43 below. These Tertiary materials are in apparentfault contact with slatey and micaceous Yavapai-Seriesto, the west. Pyramid Peak, Cave Creek district, OaisyMtn. quad., Maricopa Co., elev. 2020' "Lat 33053.24' N, Long 1120 04.12' W(RS-3-78).
1.9851.9711.969
1.5001.5741.570
1.975
1.575
94.0194.21394.25
40.70413.5948.75413.49
15.4715.9016.31
30.2530.3930.3030.57
27.29 t 0.57
17.72 t 0.37
15.39 ! 0.40
12.19 ! 0.22
13.60 t 0.34
26.9428.1027.87
60.8860.7360.77
, 50.650.550.6
20.1320.3320.31
11.9712.7412.14
16.2416.2416.37
0.606
0.579
0.856
0.6060.6020.611
0.8550.8600.853
Whole rock, mesa capping basalt uncomforfllablyoverlying about 300' of fluvial sediments includingdolomite beds and pyroclastic rocks. The sectiondips NE 20-350• Black Canyon Shooting Rangesection, Biscuit Flat quad., Maricopa Co., Lat 330
48.70' N, Long 1120 08.87' W.
Whole rock, basalt. The volcanic flow is contained 0.579within a section of sediments and pyroclastics which 0.578are juxtaposed against Precambrian granites and are 0.581pedifllented and overlain by basin fill along the easternmargin of the Big Sandy Valley near Wickieup. Uraniummineralization is found in certain horizons in thesediments. Burro Wash, Wickieup district, Tu1e Washquad., Mohave Co., elev. 3040', Lat 340 48.15' N, LongllJo 32.93' W(RS-2-79).
Whole rock, basalt dike intrusive into a rockfaulted and folded terrain of mid-Tertiarybasalts, tuffs, clastics, and limey beds. Thesection contains uranium mineralization. New River,Oaisy Mtn. quad., Maricopa Co., elev. 2220',Lat 330 54.25' N, Long 1120 03.50' W(RS-13-78).
UAKA78-45
UAKA78-44
UAKA78-43
78-46 Whole rock, thin welded rhyolite flow ,occurring.discontinuously about 500-800' above base of typeArtillery Formation, west of Artillery Peak. flowis now, thought to be intercalated into the sedimentsrather than a sill. Artillery Peak 15' quad., Lat34022.13' N, Long 1130 36.13' W.(RS-3-79).
3.4853.5333.4613.5533.5483.566
3.523 120.71122.18123.86
18.817.318.0
19.90 t 0.47
-100-
University of ArizonaIsotope Ceochemistry LabD.na: 1 June 1979
Sacple:{o.
78-47
78-48
Table 2. (continued)
Sample description and location
Whole rock, partially welded rhyolite flow intercalated into an arkosic sandstone-mudstone-limestonesection in Western Gila Bend Mtns. Sediments are Ina down thrown tilted fault block, and are depositionalon crystalline rocks. Oendora Valley l5'quad" Lat330 13.40' N, Long 1130 13.62' W(RS-4-79).
Whole rock, basalt, from near the base of a10-300 SE dipping 1000' thick volcanic section'underlain by 60' of red arkosic conglomerate andoverlain by uraniferous low energy clastics. Thisentire sequence depositional on granite to theeast and overlain unconformahly by an uppervolcanic series containing UAKA 78-3l.Black Buttedistrict, elev. 2390', Maricopa Co., Aguila quad.,Lat 330 51.62' N. Long 1130 02.80' W(RS-5-79).
Constants usedl' -10 -1. Aa• 4.963 x 10_10 yr_1. A • 0.581 x 10_10 Yr_l
40 r. 5.544 x 10_4 yrK/K • 1.167 x 10 atom/a:cm
Redio-Indlvl- genic Percentdual. Percent ergon-40 atmo- AS" inK K x 10-12 spheric cilllonanalysu used 1ll01e/s argon-40 years
2.550 '2.554 105.83 J9.9 23.64 ± 0.512.560 . 105.84 40.02.551 105.48 40.1
104.28 37.7
1.016 1.016 35.62 17.04 20.02 ± 0.421.016 35.47 16.891.016 25.30 17.12
78-49
79-66
Whole rock, andesite, from a thick andesite-brecciasilicic flow sequence which is tilted SW and juxtaposed against a cataclastically deformed crystallinecomplex by a low angle "discoloration surface".Smith Peak 7.5' quad. Lat 340 02.97' N, Long 113017.08' W. (RS-6-79).
Whole rock, basaltic andesite, in a 500-BOO' thickandesite-conglomerate sequence with 30-400 diptoward the northeast. The sample represents- aflow, about 1/5 the way up the sequence. Thesequence is overlain by fluvial arkosic red beds.Red beds contain clasts of granites and andesites.Box Canyon on the Hassayampa River, Wickenburgdistrict, Sam Powell Peak quad., Yavapai Co.,elev. 2210', Lat 340 02.72' N, Long 112043.60' W(RS-7-79).
~lal-
4.122 4.106 114.08 7.94.112 113.54 9.14.083 113.25 8.0
110.22 8.1
1.804 1.801 51.75 9.351.BOO 52.10 9.261.800 52.09 9.55
15.77 ± 0.32
16.57 ± 0.35