Jd

Q tc

T vs

Q tc T fJgd

Jgd Q tc

T fT vs

T f

T f

Jd T vs

JdT f

Jdg

Q tcQ tc

JdgJg

Jg

Jdl

Jgda

Jg Jg Jdg

Jd

Jd

T cb

Jd

Jd

T vs

Q i4 Tcb Q y1Q i2Q i2T cbT cb Q i2

Q i2 T fgQ i3 Q i2

Q i2Q i3

Q y1

Q y1Q i2 Q i3

Q i3

Q i4Q i4

Q i3Q i3

Q i2

Q i3

Q y2

Q y2

Q i4

Q y1

Q y1T cb

Q y1

Q i3 Q i2Q i2

Q tc

Q ch

T cbT cb

Q tc

Q i4

Q y1Q i4

Q i2

Q i4

Q chQ ch

Q y1Q i1

T cb Q i1Q i4

Q chQ ch

T cbQ i3

Q y1

Q y1

Q i3

Q i4

Q y1

Q y2

Q ch

Q y1

T cb Q i4

Q i1

T fg2

Q y1

Q i2

Q i3Q y1

Q ch

Q i4

T fg2

Q y1Q y1

Q i1

Q y1

Q i4

Q i3

Q i3

Q ch

Q i3

Q y1

Q y1

Q chQ y1

Q i4Q y1

Q ch Q i3 Q i2

Q i4Q i3

Q y1

Q chQ i3

Q i3

Q y1Q i4

Q i4

Q y1Q y1

T cb

Q ch

Q y1

Q y1Q y1Q y1 T cb

Q ch Q i1Q y1

Q i3 Q i2

Q i4 Q i4Q i4

Q ch Q i2

T cb

Q y1

Q y2

Q i4 Q i2

Q y1

Q i2

Q y2

Q i2

Q chQ y1

Q y2 Q i3aQ i4

Q i4

Q i2

Q i3bT cb

T cb

Q y1Q i3b

Q i2

Q i3b Q i3bT cb Q i3

Q i2

T cbQ i3b

Q i3Q i3b

Q y1

Q y2

Q ch

Q chQ y1

Q i3

Q y3

Q y1Q y1

Q y1

Q i3

Q i3Q i3

Q i3

Q ch T cb Q y1

Q y1Q y1

Q i4

Q y3

Q chQ y2

Q ch

Q i2

Q y1Q ch

Q i2

Q y1 Q i4

Q y1Q ch

Q y1Q i2

Q y1Q i4

Q cc1

T cb

Q i3

Q i3

T cbQ i2

Q i3

Q y1Q i3

Q i2

Q y1

Q y1

Q cf

Q i2T cb

Q i2Q y Q i3

T cbT cb Q i3T cb

Q i3

Q y3

Q i3Q y1

Q i1

Q y1 Q i4

Q i4Q i4 Q y1

Q i4

Q i4

Q si

Q i2

T cb

Q i3

Q i4

Q y1

Q i4

Q i4T cb

Q i4

Q i3

Q y1

T cb

Q i4

Q y1

Q y1

Q i4

Q i4Q i4Q y1 Q y1

Q i4

Q i4

Q y1

Q i4Q i4Q i4

Q i4

Q y1

Q i4Q y1

Q y1

Q y1

Q y1

Q y2

Q y2

Q y2Q y2

Q y1

Q y1

Q y3

Q cc1

Q cc1

Q y1

T fg

JgdaJd

Q tc

Q y1

Q i4

Q tc

Q i3

Q tc

Q i2

Q y2Q y2

Q y2

Q i4T fg2

Q i2

Q i4

Q i2

T f

Jd

Q i4

T fg2

T fg2

Q i3

Q i3

Q i4

Q i4

Q y2

T fg

Q y2

Q y1

Q y1

Q y1

Q y1

Q y2

Q y2Q y2

Q y2

Q y1

Q i4Q y1 Q y1

Q i3

Q i4

Q i4

Q i4

Q y1 Q y1

Q i4

Q i3

Q i3b

Q i3

T cb

T cb

Q i2Q i4

Q i4

Jd

T cb

T fg2

T bcb

Q i3 T fg2

T fg2Jd

Q y1

Q y1

Q tcQ y1

Q i2 Q i3T fg

Q i3Q y1

Q i2

Q tc

T fg

Jdl

Q i4Q i4

T cb

Q i2

Q i2

Jd

Q i3

T fg

Q i4

T fg

Jd

T fg

Q i4

T cbf

Q ch

T cb

Q ch

Q y1Q y2Q y1 Q y2

Q y1Q y2Q i4

Q y1

Q y2Q y2

Q y2

Q y2

Q y1

Q y2 Q y1Q y2

Q y2

Q y2

Q y2

Q y2

Q y2

Q y2

Q y2

Q y2

Q y2Q y2

Q y1Q y2

Q y1

Q y1Q y1

Q y2 Q y1

Q y2

Q y2

Q y3

Q y1

Q y2

Q y1

Q y1

Q y1 Q y1

Q y2 Q y2

Q y2

Q y2

Q y2

Q i3Q i4

Q i4

Jg

Q i3T fg2

Q y2

Q y2

T cb

Q y2Q y1

Q y2

Q y2Q y2

Q y1

Q i4

Q y2

Q y2 Q y2Q y2 Q y1

Q y1 Q y2

Q y2

Q y2

Q y3

Q y2Q y2

Q y2

Q y2

Q y2

Q y2

Q y2

Q y2

Q y2

Q y1

Q y1

Q y1

Q y1

Q y1

Q y

Q y1

Q y2

Q y2

Q y2

Q y2Q y2

Q y2Q y1

Q y2

Q y2

Q i4

Q y1Q y2

Q i3

T cb

T cb

Q y2Q y2

Q y1

Q y3

Q y3

T cbQ i3

Q i2

Q i2

T cb

Q i4T cb

Q i3

Q y3

T cb

T cb

T cb

Q cc2

T cb

Q i2

Q ch

Q i2u Q y1

Q siQ i3a

Q si

T cb

Jd

Q i3

Jd

T fg2

Jg

Q i3

T cb

T fg

Q y3

T cb

Q y2Q y2Q y1

Q y2

Q y1Q y1Q y1

Q y1 Q i3 Q i3

Q i3 Q y1 Q i3

Q i3

747036

6

25

65

65

45

6666

80

43

4041

5174

1484

78

54

84

46

56747

85

49

45

41 54 80 6448

45

45

54

9070

2874

62

45

61

35

72

81

70

53 4969

48

11-18-14-1T UK44

114°30'0"W

114°30'0"W

114°32'30"W

114°32'30"W

114°35'0"W

114°35'0"W

114°37'30"W

114°37'30"W33°30'0"N

33°30'0"N

33°27'30"N

33°27'30"N

33°25'0"N

33°25'0"N

33°22'30"N

33°22'30"N

721000

721000

722000

722000

723000

723000

724000

724000

725000

725000

726000

726000

727000

727000

728000

728000

729000

729000

730000

730000

731000

731000

732000

732000

3696

000

3696

000

3697

000

3697

000

3698

000

3698

000

3699

000

3699

000

3700

000

3700

000

3701

000

3701

000

3702

000

3702

000

3703

000

3703

000

3704

000

3704

000

3705

000

3705

000

3706

000

3706

000

3707

000

3707

000

3708

000

3708

000

3709

000

3709

000

Citation for this map:

G oote e , B.F., S pe nce r, J.E ., T osdal, R .M ., Pe arthre e , P.A., and House , P.K., 2016, G e ologic map of the M ule W ash 7 ½' Q uadrangle , L a Paz County, Arizona: Arizona G e ological S urve y Digital G e ologic M ap DG M -117, scale 1:24,000.

Research supported by the U. S. Geological Survey, National Cooperative Geologic Mapping Program, under USGS award number G14AC00424. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Government.

Introduction

T he M ule W ash 7 ½' Q uadrangle is locate d in w e ste rn Arizona e ast of the Colorado R ive r and southe ast of the town of Blythe , California. T he Q uadrangle e ncompasse s the w e st flank of the northe rn T rigo M ountains and most of the e ast-w e st e xte nt of the pie dmont that e xte nds from the foot of the range toward the Colorado R ive r. G e ologic mapping was done unde r the joint S tate -Fe de ral S T AT E M AP program, as spe cifie d in the N ational G e ologic M apping Act of 1992, and was jointly funde d by the Arizona G e ological S urve y and the U.S . G e ological S urve y unde r S T AT E M AP assistance award #G 14AC00424. M apping was compile d digitally using E S R I ArcG IS software . Pre viously unpublishe d be drock mapping by R ichard T osdal (form e r U S G S e mploye e ) was incorporate d into the map with minor re visions, and Kyle House (curre nt U S G S e mploye e ) assiste d with fie ld mapping.

S urficial ge ologic units including tributary and rive r de posits w e re mappe d using fie ld obse rvations, ste re o ae rial photographs, ge ore fe re nce d digital orthophotographs and sate llite image ry, and digital e le vation mode ls (DE M s).

R e lative age s of alluvial de posits and surface s w e re e stimate d using characte ristics of clast w e athe ring, soil de ve lopm e nt, carbonate accum ulation, and position in the landscape . M ost of the pie dmont is cove re d by Q uate rnary alluvial fan, te rrace , and channe l de posits transporte d by alluvial syste ms that originate from adjace nt T rigo M ountains. T he se de posits are pre dominantly locally-de rive d grave l with minor re worke d Colorado R ive r grave l clasts, and local and Colorado R ive r sand. T he se tributary Q uate rnary de posits are thin, and only partially cove r unde rlying Colorado R ive r sand and grave l and olde r tributary fan de posits. M ost of the tributary de posits cove ring the pie dmont are late Ple istoce ne or younge r in age , with uncommon to rare high de posit re mnants that re cord middle Ple istoce ne and olde r de position. T he late ral e xte nt of Holoce ne de position is confine d topographically by olde r de posits, but valle y bottoms cove re d by young de posits are commonly quite wide , and distribution of de posits of diffe re nt age s within the Holoce ne is quite comple x, re cording shifting patte rns of de position.

De posits associate d with the Colorado R ive r include the e arly to middle Plioce ne Bullhe ad Formation and the late Ple istoce ne Che m e hue vi Formation E sse ntially all of the e xposure s be ne ath Q uate rnary de posits in the valle y are Bullhe ad Formation sand and rounde d e xotic grave l (T cb), with silt and clay be ds (T cbf). Bullhe ad de posits are commonly inte rbe dde d with tributary fan grave l de posits (T fg2). Bullhe ad de posits re cord massive aggradation by the e arly Colorado R ive r in the e arly to middle Plioce ne following an unknown amount of e rosion of Bouse de posits. Che m e hue vi Formation silt, clay, sand, and grave l de posits (Q ch) are found fairly close to the valle y axis, whe re the y typically are banke d up against and drape d ove r e rosional topography form e d on Bullhe ad de posits. L ocally, fairly promine nt fluvial scarps associate d with Che m e hue vi de position are pre se rve d as strath de posits.

T he late st M ioce ne to e arly Plioce ne Bouse Formation in the map are a consists of one to se ve ral m e te rs of bioclastic lim e stone , gray tufa or trave rtine , and marl; no outcrops of fine siliciclastic Bouse (T bs) we re found, but the y have be e n inte rpre te d in the subsurface of the basin from ne arby w e ll logs (cross-se ction AA’). All carbonate outcrops are at or ne ar the be drock mountain front drape d ove r an e rosional landscape of pale o-hillslope s and valle ys. Pre - and syn-Bouse tributary fan grave ls (T fg1) are re lative ly uncommon or unmappable , but whe re the y are in contact with the basal Bouse carbonate d de posits, tributary grave ls are ofte n re worke d and w e ll-rounde d into a basal grave l de posit (T bg). T he de positional e nvironm e nt of the southe rn Bouse Formation is dispute d: the y are e ithe r lacustrine de posits associate d with the arriving Colorado R ive r or e vide nce of a marine e m baym e nt that partially pre date s the de ve lopm e nt of the rive r.

Be drock in the map are a consists primarily of Jurassic granitoid rocks with le ss abundant Oligoce ne to e arly M ioce ne fe lsic volcanic rocks and shallow intrusions. G ranitoids are dominate d by dark hornble nde diorite to hornble nde -biotite quartz diorite , with le ss abundant granodiorite and le ucodiorite . T he granitoids are associate d with diorite schist and gne iss and biotite auge n gne iss. Foliation ge ne rally strike s northw e st and dips northe ast and is associate d with a northe ast plunging line ation. T he Oligoce ne to e arly M ioce ne volcanic units include both shallow intrusions and be dde d volcanic-lithic clastic to volcaniclastic units. At one location an intrusive contact be tw e e n a fe lsic intrusion and be dde d volcanic-lithic conglom e rate is cle arly e xpose d. T he be dde d rocks are tilte d ste e ply to the northe ast and, although faulte d against the Jurassic granitoid rocks, sugge st that all of the e xpose d be drock was tilte d ste e ply to the northe ast by M ioce ne e xte nsional faulting.

Piedmont Surficial units

Pliocene to Pleistocene map units related to the Colorado River

Bouse Formation, basal gravels - G ray to gre e nish-gray, locally de rive d, subangular to w e ll-rounde d, w e ll-sorte dgrave ls and cobble s with calcare ous sand le nse s at the base of the Bouse Formation. Include s coarse grave lbe ds with 1- 5 cm clasts. T his unit is e xpose d primarily in the southe aste rn corne r of the map are a. T he sese dim e nts are re worke d from unde rlying colluvium and fan de posits. T he de posits range from coarsefanglom e rate cobble s and pe bble s to sand-dominate d facie s and include mode rate to w e ll-sorte d, w e ll-rounde dbe ach and ne arshore grave l de posits. Be ds from this unit are ove rlain by, and locally inte rbe dde d with, Bousebioclastic lim e stone (unit T bcb).

Tbg

Bouse Formation, tufa - M assive tufa de posits and scabrous e ncrustations, typically fossilife rous, algal andmicrobial forms, he misphe rical shape s, commonly drape d on mode rate ly-sloping pale o-hillslope s form e d onbe drock and olde r, e rode d fanglom e rate and colluvium. Also found as cobble and boulde r aggre gations withinmarl and bioclastic lim e stone de posits. Color of tufa range s from light to dark gray. T his unit range s from a fe wcm thick up to 1-2 m thick.

Tbct

Bouse Formation, bioclastic limestone and resistant marl - Pale gray to tan, ge ne rally thin-be dde d, mode rate ly tow e ll-sorte d bioclastic lim e stone , typically containing abundant ske le tal-barnacle fragm e nts. Inte rnal se dim e ntarystructure s are ofte n w e ll-pre se rve d, and include paralle l lamination, both wave ripple and unidire ctionalcross-lamination, and trough and tabular crossbe d se ts. Bioclastic lim e stone be ds are ge ne rally inte rbe dde dw ithin more abundant marl and calcare ous siltstone . T bg pe bble be ds and le nse s are common within bioclasticlim e stone facie s. T his unit is ge ne rally 1-3 m thick and is typically pre se nt adjace nt and down dip from massivetufa de posits drape d on be drock.

Tbcb

Bouse Formation carbonate deposits - Carbonate -rich de posits undivide d including algal lim e stone , massive tufadrape s on pale ohillslope s, and thin-be dde d calcare nite and lim e marl.Tbc

Bouse Formation, siliciclastic deposits - Fine -graine d sand, mud and clay de posits pe ne trate d by w e llsimm e diate ly north, w e st and south of the map are a (se e cross-se ction AA'). Unit T bs is e xpose d south of the mapare a ne ar Cibola (G oote e e t al., 2015).

Tbs

Bullhead Alluvium - Unconsolidate d to mode rate ly consolidate d w e ll-rounde d to subangular cobble s and pe bble s,quartz-rich sand, and le sse r amounts of silt and clay. S urface s of the se de posits are commonly mantle d bygrave l, and grave l be ds are common, but sandis the dominant particle size in the map are a. R ounde d pe bble sand cobble s of primarily quartzite , che rt, and othe r re sistant rock type s. T e ntative ly corre late d with the Bullhe adAlluvium (Howard e t al, 2015), but locally may include Q uate rnary Colorado R ive r de posits.

Tcb

Intermediate alluvial fan and terrace deposits, undivided - Undivide d de posits with darkly varnishe d surface s,variable pave m e nts, primarily e quivale nt to Q i3 and Q i4, may include som e Q i2 de posits.Qi

Oldest intermediate alluvial fan deposits - Poorly sorte d cobble , pe bble , sand de posits, with minor silt, clay, andboulde rs. De posits are found capping mode rate ly high ridge s, and typically are 15-25m above active washe s.Planar surface s are ge ne rally fairly narrow and margins are substantially rounde d. De posits typically are a fe wm e te rs thick ove r unde rlying fan de posits or Bullhe ad alluvium. S oil de ve lopm e nt range s from strong onw e ll-pre se rve d surface s to w e ak to mode rate on e rode d slope s.

Qi1

Colorado River active channel deposits - De posits subm e rge d be ne ath the mode rn channe l of the ColoradoR ive r. Include s grave l, sand, silt and clay, poorly e xpose d. M argins of this unit are form e d by man-made le ve e s.Qcc2

Colorado River inactive channel and floodplain deposits - S and, grave l, silt, and clay de posits in re ce ntlyabandone d rive r channe ls, bars, and low te rrace s. T he se de posits are ve ry similar to Q cf and Q cc2 de posits, allare late st Holoce ne rive r de posits, but the se are as have not be e n cultivate d but are isolate d from the active rive rchanne l by man-made le ve e s.

Qcc1

Colorado River floodplain deposits - De posits of the Colorado R ive r floodplain. Poorly e xpose d, e ntire ly cove re dby agricultural fie lds. Prior to cultivation, the se are as ce rtainly include d active and re ce ntly active channe ls, bars,and low te rrace s. De posits consist of sand, silt, clay, and grave l.

Qcf

Chemehuevi Formation - S and, silt, clay and minor Colorado R ive r grave l de posits drape d ove r olde r pie dmontand Colorado R ive r de posits. T he se de posits re cord a pe riod of major aggradation by the Colorado R ive r in thelate Ple istoce ne (M almon e t al., 2011, U S G S PP 1786). N orthe ast-southw e st tre nding scarps re pre se nt a se rie sof re ce ssional te rrace s strathe d on olde r de posits. T he e arlie st Q ch de posits may be coe val w ith post-Q i2 andpre -Q i3 de posits (Unit Q i2u).

Qch

Bullhead Alluvium, fine-grained deposits - T hin to m e dium be dde d silt, clay, and fine sand de posits, spatiallyassociate d w ith coarse r-graine d Bullhe ad Formation de posits and tributary fan grave l de posits. R e lative ly lowlandscape position, probably grade s late rally and up-se ction into coarse r Bullhe ad de posits.

Tcbf

Youngest intermediate alluvial fan and terrace deposits - G rave lly de posits in low te rrace s and alluvial fans.De posits consist of pe bble s, cobble s, small boulde rs, sand, silt and clay. M ode rate varnish on clasts, w e ak tomode rate undulating de se rt pave m e nts, but not was w e ll de ve lope d as Q i3. S oil de ve lopm e nt include s ve ry slightre dde ning, visible carbonate accum ulations. Ve ge tation is sparse and conce ntrate d along slightly incise d smalldrainage w ays.

Qi4

Intermediate fan and terrace deposits, lower level - Younge r Q i3 de posits that cle arly post-date maxim umaggradation of the Colorado R ive r in the late Ple istoce ne . Q i3b surface s are broad and flat with stronglyvarnishe d and w e ll-de ve lope d pave m e nts with subtle bar and swale topography. T he ve siclur horizon is is up to10 cm thick on this surface . Q i3b is 2-3 m be low Q i3a.

Qi3b

Intermediate fan and terrace deposits, higher level - Highe r Q i3 surface s grade d approximate ly to the highe stle ve l of Che m e hue vi rive r aggradation. S urface s with dark, w e ll-de ve lope d pave m e nts are inse t ~5-10m be lowQ i2 surface s. Q i3a surface s are slightly more rounde d than the younge r Q i3 surface s, with more carbonatede ve lopm e nt on clasts with mm thick rinds.

Qi3a

Intermediate alluvial fan and terrace deposits - Ve ry poorly sorte d de posits including pe bble s, cobble s, sand,minor silt and clay, locally boulde rs forming late rally e xte nsive re lict alluvial fans and te rrace s. S urface s aretypically 1-5m above adjace nt Holoce ne de posits, S urface s vary from undulating to ve ry smooth, de se rtpave m e nts are mode rate ly to strongly de ve lope d and rock varnish is quite dark. S oil de ve lopm e nt is mode rate ,with slight re dde ning, minor clay accum ulation, calcic horizon de ve lopm e nt II-III.

Qi3

Intermediate deposits beneath Chemehuevi deposits - Inte rm e diate to young fan de posits compose d oflocally-de rive d grave l and sand. T his unit is younge r than high-standing Q i2 de posits and pre -date s unit Q ch rive rte rrace de posits. A diagnostic cobble -grave l lag caps this unit unde rlying Q ch de posits. Unit Q i2u ge ne rallypre -date s younge r Q ch de posits, but are inte rfinge re d w ith olde r Q ch de posits. W e inte rpre t Q i2u to be ge ne rallycoe val with the main Che m e hue vi aggradation e ve nt, although it may be olde r than Q ch in som e localitie s.

Qi2u

Older intermediate alluvial fan and terrace deposits - Poorly sorte d pe bble s, cobble s, sand, minor silt and clay,som e boulde rs. associate d with mode rate ly disse cte d re mnant te rrace s ~5-20 m above active washe s. R ockvarnish and pave m e nt de ve lopm e nt is variable , quite strong on w e ll-pre se rve d surface s and mode rate to w e akon more e rode d surface s. S oils are obviously re dde ne d be ne ath pave m e nts, and carbonate rinds are mode rate lythick.

Qi2

Deposits forming low terraces and active fans - G rave l, sand, and silt de posits forming low te rrace s and smallalluvial fans, locate d primarily along the flanks of active washe s. T he se de posits are unconsolidate d to ve ryw e akly consolidate d se dim e nts, poorly sorte d with sub-rounde d to sub-angular pe bble to cobble bars on thesurface and be ds and le nse s in cross se ction. T opographically low are as commonly are cove re d by thin mantle sof silt and clay. S oil de ve lopm e nt is minim al. Ve ge tation include s de se rt riparian tre e s and shrubs.

Qy2

Low terrace and low relict alluvial fan deposits - G rave l, sand, silt and clay de posits forming re lict alluvial fansand te rrace s along large r pie dmont drainage s. Q y1 de posits are compose d of silt to pe bble s in swale s, and lightly to mode rate ly varnishe d pe bble s to small boulde rs in bars. T he se de posits are ge ne rally locate d on themargins of incise d valle ys away from the more active parts of the drainage syste ms, and typically are 1-2mabove adjace nt active washe s. Ve ge tation include s sparse , re lative ly small de se rt riparian tre e s, shrubs includingcre osote , and cacti.

Qy1

Young channel, terrace and alluvial fan deposits, undivided - Poorly sorte d pe bble s, cobble s, sand, minor siltand clay, locally boulde rs. Associate d w ith active and re ce ntly active w ashe s, and slightly highe r te rrace s withmode st rock varnish, minimal soil de ve lopm e nt.

Qy

Sand sheet deposits - L ate rally e xte nsive sand de posits, with minor grave l, silt and clay; not spatially associate dw ith active drainage s. Pe rce nt cove rage of sand is variable , but typically is >50 pe rce nt, Include s small are as ofgrave l lag, and e rode d fine -graine d de posits.

Qsi

Colluvium and talus - Unconsolidate d, ve ry poorly sorte d, angular to subangular cobble , pe bble , sand, silt andclay de rive d from adjace nt be drock, on mode rate to ste e p hillslope s.Qtc

Deposits in active channels, low terraces and bars - Pie dmont grave l, sand and silt de posits locate d along activedrainage s, including channe ls, adjace nt grave l bars and low te rrace s, and broade r distributary multi-channe le xpansion re ache s. Q y3 de posits are poorly sorte d and unconsolidate d, grave l clasts are not varnishe d unle ssre worke d from olde r de posits, and soil de ve lopm e nt is minim al. Ve ge tation include s de se rt riparian tre e sincluding palo ve rde , ironwood, and m e squite .

Qy3

De scription of map units

AZCA

Miocene to Pliocene map unit

Oligocene to Miocene map units

Kitt Peak - Trigo Peaks superunit (Jurassic)

Volcanic-lithic tuffaceous sandstone and conglomerate - R ocks of this unit are be dde d to massive and consistlarge ly of tufface ous sandstone and volcanic-lithic conglom e rate with a tufface ous matrix. Brown volcanic-rockfragm e nts and pale gray and tan tufface ous clasts are up to 10 cm diam e te r. Be dding is de fine d by sorting andvariable abundance of fragm e nts. Hornble nde is pre se nt in som e rocks of this unit. S om e massive , light colore drocks include d in this rock unit may be alte re d lavas or pyroclastic rocks. Flatte ne d volcanic-lithic fragm e nts thatwould indicate compaction of hot pyroclastic rocks w e re not se e n. R ocks of this unit are typically light in color onae rial image ry compare d to darke r-w e athe ring intrusive fe lsite . T his rock unit is close ly associate d with fe lsicintrusions of map unit T f which cle arly intrude s it in its northe rn are a of e xposure .

Tvs

Younger fanglomerate - Poorly sorte d, w e akly to mode rate ly lithifie d sandstone , conglom e ratic sandstone , andconglom e rate . Clasts consist large ly of subangular to angular locally de rive d T e rtiary volcanic rocks, granite anddiortie , but include s trace to se ve ral pe rce nt clasts of tufa and bioclastic calcare nite , rounde d local clastsre worke d from T fg de posits, and rounde d black che rt and quartzite e rode d from coe val Bullhe ad Alluviumde posits. T his unit thus re pre se nts mostly locally de rive d fan mate rial inte rfinge re d with minor amounts ofColorado R ive r de rive d se dim e nts. Unit T fg2 grade s late rally into unit T cb towards the basin, and locally isunconformably ove rlain by unit T cb. Unit T fg2 e rosionally ove rlie s be drock and Bouse strata.

Tfg2

Older fanglomerate - Poorly sorte d, light brown conglom e rate and conglom e ratic sandstone with angular torounde d clasts of local volcanic rocks, granitoids including locally de rive d Jurassic diorite . T he uppe rmost part ofthis unit imay be coe val with Bouse de position. T he top of this unit grade s conformably into the basal Bouse units(T bg, T bct, or T bc), but in othe r are as basal Bouse de posits are drape d disconformably ove r intact fan surface s.

Tfg1

Fanglomerate, undivided - L ocally source d ve ry poorly sorte d boulde rs, pe bble s, cobble s, sand, with minor siltand clay. R e lationship to Bouse de position and late r Bullhe ad aggradation is not cle ar, but w e suspe ct that moste xpose d T fg is roughly coe val with Bullhe ad aggradation.

Tfg

Felsic hypabyssal igneous rocks - R ocks of this unit consist primarily of massive fe lsic e xtrusive and/or shallowintrusive rocks that are locally bre cciate d or flow bande d. Contacts with adjace nt be dde d volcanic-lithic rocks areste e p and, at one location (and probably anothe r), cle arly intrusive . Unit contains <20%, <10 m sanidine(<10%, <3mm sanidine in most sample s), <7%, <3mm hornble nde , and <3%, <2mm biotite .Plagioclase conte nt is difficult to de te rmine in hand sample s e xce pt w he re plagioclase is chalky due to alte rationwhile sanidine is unalte re d. Plagioclase made up ~20% of one sample , with chalky phe nocrysts up to 10mm.Q uartz was not ide ntifie d in most sample s, although one sample contains 4-7%, <3mm quartz. S om e rocks arew e akly to mode rate ly vitric.

Tf

Diorite - M e socratic to m e lanocratic hornble nde diorite , biotite -hornble nde diorite , biotite quartz diorite ,hornble ndite , and m e tamorphose d e quivale nts. L ocally characte rize d by primary compositional laye ring ofalte rnating plagioclase -rich and hornble nde -rich laye rs a fe w ce ntim e te rs thick. Corre late d to diorite rocksinclude d in the Araz W ash diorite unit throughout the low e r Colorado R ive r re gion with age s be tw e e n 169 and173 M a (T osdal and W oode n, G S A S pe cial Pape r 513). Contains mappable units of map units Jdl and Jdg.

Jd

Dioritic gneiss and schist - Foliate d biotite quartzofe ldspathic gne iss, biotite schist, and amphibolite . L ocallyforms fine ly laye re d, foliate d se que nce pre sum ably de rive d from originally compositionally laye re d dioriteintrusive comple x.

Jdg

Leucodiorite - Diorite that is rich in plagioclase and poor in mafic silicate s. Unit forms mappable bodie s withinthe large r diorite unit (map unit Jd).Jdl

Granite - L e ucocratic, m e dium graine d, biotite monzogranite to granite . L ocally foliate d along contact margins. Pe gm atite and aplite dike s re late d to large r bodie s are common throughout olde r porphyritic granodiorite andde rivative auge n gne iss (units Jgd and Jgda) as w e ll as phase s of the diorite unit (units Jd and Jdl) and de rivativem e tamorphic rocks. Commonly form dike s 0.5m to 10m thick too small to map. One dike has a U-Pb age of163.0 ± 2.6 M a (T osdal and W oode n, G S A S pe cial Publication 513). L ocally intrude d by L ate Jurassic(?)hornble nde -biotite diorite dike s too small to be mappe d se parate ly.

Jg

Porphyritic granodiorite - M e dium- to coarse -graine d hornble nde -biotite porphyritic granodiorite and de rivativeauge n gne iss. Characte rize d by K-fe ldspar phe nocrysts as much as 5 cm in le ngth. Corre late d to similar rocksinclude d within the M iddle Camp porphyritic unit throughout the low e r Colorado R ive r re gion with age s be tw e e n164 and 168 M a (T osdal and W oode n, G S A S pe cial Pape r 513). Xe noliths of diorite are common. L ocallyintrude d by L ate Jurassic(?) hornble nde -biotite diorite dike s too small to be mappe d se parate ly. Containsmappable units of Biotite auge n gne iss (map unit Jgda).

Jgd

Biotite augen gneiss - Unit is characte rize d by pe ne trative foliation marke d by biotite , e longate gre y to bluishquartz, and alignm e nt of K-fe ldspar porphyroclasts. Unit is me tamorphose d e quivale nt of the porphyriticgranodiorite unit (map unit Jgd).

Jgda

A

A'

Arizona G e ological S urve y Digital G e ologic M ap DG M -117G e ologic M ap of the M ule W ash 7 1/2' Q uadrangle

T opographic base map de rive d from M ule W ash 7.5' U S G S topographic quadrangle map originally with N AD27 datum. R e proje cte d to U T M N AD83 datum (zone 11) using iG age All T opo M aps V9. U T M N AD 83 grid and lat-long marke rs produce d using E S R I ArcM ap v. 10.4.

S CAL E 1:24,0001 0 10.5 M ile s

1 0 10.5 Kilom e te rs

0 1000 2000 3000 4000 5000Fe e t

CON T OU R IN T E R VAL 20 FE E T

N am e d quadrangle s are mappe d by AZG S or mapping is in progre ss

Cibola

M ule W ashN orth T rigo Pe aks

M oon M ountain S E

M iddle Camp M ountain

Dom e R ock M ountains S W

¬«95

£¤95

£¤60§̈¦10 Quartzsite L ocation of

map are a

Distance (m)

A A'

Geologic Cross SectionCrazy Woman fan - Trigo Mts - Gould Wash

View to Northeast

720,820 E3,698,910 N

732,460 E3,695,700 N

B-01-23-28BAA

2.2 km W

TrigoMountains

Qch scarp

Qch scarp

Qch scarp?

?

T cb

T b

T fg

T bc ~305 m-e le v

Fine sand, blue andye llow clay

T fg2T cbT cb

Jd

JdJd

bend in section

JgdT f

T f

T vs

T vs

T f

bend in section

9 m-e le v

-176 m-e le v

T cb

T bs

T bc

Primarily Q i de positsPrimarily Q y de posits

Ve rtical e xagge ration = 3xS cale 1:24,000

Qi3

TbcTbc

Qch

Tfg2

0 5000 10000

0 0

500 500

Elevation (m)

L e ge ndContacts, faults, and dikes

Contact, gradationalContact, approximate

G ranitic dikeFault, approximateFault, accurateFluvial scarp, tics on down-slope side

Contact, accurateStructure symbols and sample locations

T e ctonic line ation, ge ne ric

S trike and dip of incline d be ddingFlow foliation in volcanic rocksT e ctonic foliation, ge ne ricT e ctonic foliation, ve rtical

G e ochronology sample

S trike and dip of joints or planar fracture s

!!

!

!

!

!YumaT ucson

Parke r

Phoe nix

Kingman Flagstaff

Arizona Geological Survey1955 E ast S ixth S tre e t, PO Box 210184

T ucson, AZ 85721(520) 621-2470www.azgs.az.gov

Corre lation of map unitsColorado Riverdeposits

Piedmont alluvialdeposits

Other deposits

Qsi

Qtc

Tf

Tvs

Qy

Qy3

Qy2

Qy1

Qi4

Qi3b

Qi3a

Qi2

Qi1

Qi2u

Qi3 Qi Qch

Qcf

Qcc2

Qcc1

Q uate rnary

M ioce ne to Plioce ne

Oligoce ne to M ioce ne

Jurassic

Pleistocene

Holocene

Jdg

Jd Jdl

Jg

Jgd Jgda

Tfg

Tfg2

Tfg1

Tbg

Tbcb

Tbct

Tbs

TcbTcbf

Tbc

G e ologic M ap of the M ule W ash 7 ½' Q uadrangle , L a Paz County, Arizona,

and R ive rside County, California2016

scale 1:24,000, 1 she e t with te xt

Brian F. G oote e , Jon E . S pe nce r, R ichard M . T osdal, Philip A. Pe arthre e , and P. Kyle House

Arizona G e ological S urve y Digital G e ologic M ap DG M -117