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Home , Blaine Formation, Buda Limestone, Cow Creek Limestone, Escondido Formation, Finlay Limestone, Indio Formation

U.S. DEPARTMENT OF THE INTERIOR Prepared in cooperation with the DATA SERIES 170 U.S. GEOLOGICAL SURVEY BUREAU OF ECONOMIC GEOLOGY PLATE 3 Version 1.1 106° 105° 104° 103° 102° 101° 100° ° Kbm Pa Osh Ein 30 Kbm Pa Osh Qao Ei Qao Ocm QTb Kyu Qls Kwfr Ppc Kcx Ein Ocm Kbd Kt MDc Kyu Osh Oj Kt Qf OEd Oၤ Qao QT Qf Qf Kbd Ked ၧci Kpr ၧ Qao ၧd ၧ Kse Kbu Oi OEd h Mt Kse Omr Kfr ၧd Qao Kse Kbo Pci MDc Qao Kbo Qal Kbo Kau Qal Kbd Ocm Qf ၧMt Qf Kpt Qao 30° Pa Qf Opf Kt Opf OEd ၧh Kbo Kbo QTb Oj Kbd Kt Kbd Kbd Kau Kbu Qf Ein Qf OEg Qao Kpt Kbu Qao Ti Qf O Qf Kbo Ked Ked Pr Kbo Qal Oi Kbo Qf MDc Ked Pr Kpr Osh Qao Qao Kt Kbo Qu QTb Kau QTu Qal Kwfr Kpt Kse QTu Kt Qf Kbd Qao OEd Pmg Ksh OEg Kt Kdv Omr Qf Qao Ksh Ocm OEg ၧMt Kpr Qf Oi Qf Kbo Kbd Kdm Oi Qao Qal Qf Kau Kbu Kdv Kbu Oi Qao Qf Kse Qal Opf Kbd Ked Qf Qf OEg Qf Kse Kdv Kbo Qt Qf Qf Kbo Qu Ksu Ksu Ti Kwfr Kt Kbd Kbu Ked Qsu Kbd Kt Kpt Kbd Opf Ti Ked Qao Kwfr Kbo Kpt Kbo Kbu Kef -M-b Qao Kbu Kau Kgr Opf Kag Qao Kdv Kdv Kbd Qal QTb Kse ၧ Kp Mt Kau Kbo Kbo QTb Kpt Kse Qu Kgr Kdr Qal OEg Kdv Kbd Kbu Kdv -M-i Qls Oi Qf Ei Kbo Kt Qal Kpt Kbu Kgr Or Ocm Ksa Ksa Qao Qao Kbd Kgr Kbd Qu Ksa Kag Qf -M-b Kpt Qal Qsu Qf QTb Qf Qal Kag Kbo Qu Kgr Kp Kef Qt OEg Kwfr Qls Kbd Qu Qal Qao Kp Kbd Qal Kgr Opf Opf Opf Kwfr Ti Kp Kbo Qt Qal Qls Or Kag Kbd Qao Kwn Ei Kag Kse Qu QTu Kag Kbo Kbo Ksa Md Kt Qf Kbd Ei Kbo Ei Ti Qf Kdr Qp Qt Kmk Oi Kpt Ei Ei QTu Qu Kwn Kag Qls O Oၤ Kbd Ei Qao Kag Kbd Oi Ei Kt Kse Qt Kdr Qal Oi Ei Ehh Kdr Kdr Qal Kmk Kgr Ev Ksa Ocm MDo Qf Ev Kbd Kbu ၤ ၧd Kse Or O c Kp Kbo Qu Kdr Qal Kgr EXPLANATION Qao Oၤc Kbu QTb -M-b Qf PAbp Ksa Qf Md ၧMt Mb Kst PAKj Qao Ksu Kef Qf Kp Kpt Kwn Osa Kag Ei Kag Kbu Kbd Ti Kdr Kbu PROVINCE NO. 2 PROVINCE NO. 1 Ti Qf Kst Qao Qu Kdr Qu TRANS-PECOS TEXAS AND EAST BANK OF PECOS RIVER NORTH AND CENTRAL TEXAS INCLUDING PANHANDLE Opf Ei Kp QTb QTu Qu Kmk Qu Ehh Ksa Qt Kbo PAKj Qf Qf Ev Kag Qt PRESIDIO COUNTY EXCLUSIVE OF PRESIDIO COUNTY Kbo Kp Qu Osa ၤ Ei Ti Qt Kpt QTu Kbu Qal Kbu Ki O c Qao Kbo Kdr Kdr Pobo Qt Ki Md Osc Oၤc Oၤc Ksa Pd Kbd Kag Pobo Qu Qal Kmk Kp Os Kef Qao Qf Kse Kef Kau Qal Kp Qf Ksu Pof Qf Qal Oi Qt Kdr Dewey Lake Redbeds P Oi Oၤc Os PAKj Qao Qao Qal Kbu Kbu Os Kef rocks, undivided Qf Ki Pru Kbo Kag Ki Kag Qf Ti Kpt Prc Pts Oၤc Os PAKj Kef Kef Kse Qls Psc Kbd QTb Kau Kau Qu Oၤc Kse Qt

Ochoa Series PAbp Kag Kbd Qal Qao Rustler (Pru), and Salado and Castile Formations, undivided (Psc); gypsum Qf Oi Kbo of Rustler, Salado and Castile Formations, undivided (Prc); and Tessey PAKj Oi (Pts) Kag Kp Kuc Qf PROVINCE NO. 6 Kuc Kac Ki Qls PROVINCE NO. 5 Qle Pt NORTH, CENTRAL, AND SOUTH TEXAS INCLUDING 29° Qf Pobo Qal Pq FOR ALL OF WEST TEXAS EAST TEXAS AND GULF COAST TO RIO GRANDE QTu Pbc Kbo Qu Pcb Py Md Pc Kbd Kes Pcl Pqw Oၤc Fs Qle Kag Kol Pmg Pbb Pwh PAKj Ksm Kes Psr PAKj Qu Pcc Pwb Qao Kp Fill and spoil Qls Kau Mina Grande Formation Pgs Pm Qal EPAin Pw Pb Kse EPAin Kol ° Pbr Qs Qds Qsd Qsu Qs Qds Qsd Qsi Qcd 29 Quartermaster (Pq) and Cloud Chief (Pcl) Formations; Whitehorse Group, undivided (Pwh); Quartermaster Formation and Whitehorse Group, Qle Bell Canyon (Pbc), Cherry Canyon (Pcc), and Brushy Canyon (Pbr), Sand sheet (Qs); dune sand sheet (Qds); sand dune (Qsd); and Sand sheet (Qs); dune sand sheet (Qds); sand dune (Qsd); undivided (Pqw); Blaine Formation (Pb); and Whitehorse Group and Qal Qal Formations; Bell Canyon, Cherry Canyon, and Brushy Canyon sand deposits, undivided (Qsu) silty sheet (Qsi); and clay dune (Qcd) Kuc Ec Blaine Formation, undivided (Pwb) Qt Formations, undivided (Pbb); Carlsbad Group (Pcb); Capitan (Pc), Tansill (Pt), Guadalupe Series Yates (Py), Seven Rivers (Psr), Goat Seep (Pgs), Munn (Pm), and Word (Pw) Formations Psa Qal Qaf Qal Qac Qas Qbr Kuc Holocene Alluvium (Qal), subdivided in Rio Grande delta into areas predominantly Qal Ksm Eb San Angelo Formation Alluvium (Qal); and alkali flat deposits (Qaf) Ksm Kes clay (Qac), and areas predominantly sand (Qas); and beach-ridge and Qle Pr barrier-flat sand deposits (Qbr) Ppc EPAin Kol PAk Pci Pco Pcf Qt Qf Qc Qgy Qls Qb Qp Qu Qt Qd Qd? Ksm Ec Pbg Pvc Pcm Pwi Terrace (Qt), alluvial fan (Qf), caliche (Qc), gypsite (Qgy), land slide (Qls), Ross Mine (Pr), Cibolo (Pci), Pbs Clear Fork Group Terrace deposits (Qt); and Deweyville Formation (Qd), with higher level, (Qd?) and Pinto Canyon (Ppc) Formations bolson (Qb), and playa (Qp) deposits; and Quaternary deposits, undivided (Qu) PROVINCE NO. 2 Eb Briggs (Pbg), Victorio Peak (Pvc), Cutoff (Pco), Bone Spring (Pbs), Qt TERTIARY IGNEOUS AND VOLCANICLASTIC ROCKS, TRANS-PECOS TEXAS Holocene & Cathedral Mountain (Pcm), and Wilkie Ranch (Pwi) Formations Plu 1 23456789 Qbc Qbs Qbv Qbb Qle Qo Qse Qli Qg Qtl Qbd Qta Qdl Qtu Kes

PERMIAN Qal Pta QTu Qt Pwr Beaumont Formation subdivided into areas predominantly clay, (Qbc), QUATERNARY Qun Qao Qhg Pgc areas predominantly sand (Qbs), in the Rio Grande delta area clay veneer Qal 20 over meanderbelt sand (Qbv), and barrier island deposits (Qbb) Qt Qu Kes Pbe -M-i Leona Formation (Qle); Onion Creek Marl (Qo); Seymour (Qse), *Lingos (Qli), and Ec Gatuna (Qg) Formations; Toy Limestone (Qtl); Blackwater Draw (Qbd), Tahoka (Qta), Ql Double Lakes (Qdl), and Tule (Qtu) Formations; pond (Qun), older alluvial (Qao), Qu Lueders (Plu), Talpa (Pta), Grape Creek (Pgc), -M-b and high gravel (Qhg) deposits Bead Mountain (Pbe), and Waggoner Ranch (Pwr) Formations Lissie Formation Qu

Leonard Series -M-d

Pleistocene QTb QT QTu Psh Pjv EPAin 25 Qhg Kes Pp PAk -M-O Quaternary–Tertiary bolson deposits (QTb); Quaternary–Tertiary deposits, Qt Skinner Ranch and Hess Formations, undivided Pec Or undivided (QT); and Uvalde Gravel (QTu) High gravel deposits Ti Jagger Bend and Valera Formations, undivided (Pjv); Elm Creek (Pec), and Petrolia (Pp) Formations Qu Osa PobPorPou Pow Opf 30 Ph Pad Oi Blanco (Pob) and Rita Blanca (Por) Formations; Willis Formation Osc Oj Paj Oj and unnamed deposits (Pou) Qt

Hueco Limestone Pcj Pliocene Pn Qal Os Kes Psb Ocm Omr PoMo

OEd Ec Pss Pse Osh 35 Og

Psm Pac TERTIARY Od Eb Pmo Oe OEv Ode QTu -M-g -M-g PAk Evh Ewm Ein Ed Pa Pin Admiral (Pad) and Coleman Junction (Pcj) Formations; Admiral and Goliad Formation Goliad Formation Coleman Junction Formations, undivided (Paj); Santa Anna Branch Shale OEc Alta Formation Lenox Hills and Neal Ranch Formations, undivided and Sedwick and Moran Formations, undivided (Pss); Santa Anna Branch EPAin Wolfcamp Series Shale (Psb); Nocona (Pn), Sedwick (Pse), and Moran (Pmo) Formations; 40 Ev -M-f QTu Sedwick and Moran Formations, undivided (Psm); and OEg -M-fo -M-fo Archer City Formation (Pac) Qt -M-o 28° Qal Ppu Fleming Formation and Oakville Sandstone, undivided Fleming Formation and Oakville Sandstone, undivided (Mfo); Ec Ti Ei Fleming Formation (Mf); and Oakville Sandstone (Mo) Pၧm Pၧh Pၧma

Eocene Eb 45 Oc Magdalena Formation ၧtg Ocf Oc ၧci Of Qt Pueblo (Ppu), Harpersville (Pၧh), Thrifty and Graham Formations, Catahoula Formation Cieneguita Formation undivided (ၧtg), and Markley (Pၧma) Formations Catahoula Formation and Frio Clay, undivided (Ocf), 28° Virgil Series Catahoula Formation (Oc); and Frio Clay (Of) ၧhc 50 OEw On OEw ၧ r Shitsett (OEw) and Nash Creek (On) Formations 1. Tertiary intrusive rocks, undivided (Ti); Quitman Mountains caldera 6. Delaho Formation and unit 9 of Rawls Formation (-M-d); Bofecillos Em ၧrp ၧcn volcanic rocks, and volcanic rocks of Sneed (Cox) Mountain and west volcano volcanic rocks, including units 1–8 of Rawls Formation and OEj of Victoria Peak, (Oq); Eagle Mountains caldera volcanic rocks (Oe); lava flows in upper part of Fresno Formation (Or); Santana Tuff from Ejl Ewb Em and Van Horn Mountains caldera volcanic rocks (Evh) Sierra Rica caldera in Mexico (Osa); San Carlos Tuff from San Carlos ၧw ၧv Eya caldera in Mexico (Osc); South Rim Formation from Pine Canyon Eca 2. Miocene intrusive rocks (-M-i); Oligocene intrusive rocks (Oi); Wiley caldera (Os); Chisos Formation of Schiebout et al. (1987) and the Big Ewb ၧwm ၧca Mountains caldera volcan rocks (Ewm); and intrusive rocks Yellow Sandstone Member of their Tornillo Formation, undivided Missouri Series (Ei) (Oec); and Eocene volcanic rocks (Ev) Jackson Group, Undivided (OEj); Whitsett Formation (OEw); Manning, Manning (Em), Wellborn (Ewb), and Yazoo (Eya) Formations ၧpp ၧjc ၧcr Wellborn, and Caddell Formations, undivided (Ejl); Manning (Em), Wellborn (Ewb), ၧpm 3. Vieja Group, including Bracks Rhyolite, Chambers and Colmena 7. Black Gap area volcanic rocks (-M-b); Jones Basalt (previously mapped and Caddell (Eca) Formations ၧ ၧmw wp Tuffs, and Gill Breccia (Oev) as Petan but not related to type locality) (Oj); and Devils Graveyard Eca Emb volcanic rocks (Oeg) ၧbr 4. Chinati Mountains caldera volcanic rocks, including Chinati Caddell (Eca) and Moodys Branch (Emb) Formations Mountains Group, Mitchell Mesa Ignimbrite, and type area of Petan 8. Jones Basalt (Oj); and Duff Formation (with Decie Member (Ode), ၧ Basalt (Ocm); upper part of Shely Group, including Tm4 of Morita from Paisano caldera shown separately), Cottonwood Spring m ၧpb Ey Ey ၧ Ranch Formation (Osh); Infiernito caldera volcanic rocks, including Basalt, Potato Hill Andesite, Sheep Canyon Basalt, Crossen Trachyte, TERTIARY gt ၧst Capote Mountain Tuff, Tsh2 of Shely Group, Buckshot Ignimbrite, and Pruett Formation, undivided (Oed) Yegua Formation ၧgr and Tm1 of Morita Ranch Formation (Ein) Yegua Formation Gaptank Formation 9. Jones Basalt (Oj); younger volcanic rocks of Davis Mountains area, ၧlb 5. Delaho and Rawls Formations, undivided (-M-O); Perdiz Conglomerate, including Brooks Mountain, Goat Canyon, Medley, Barrel Springs, Des Moines Series Tascotal Formation, and tuffaceous sediments of Fresno Formation, Wild Cherry, Eppenauer Ranch, Mount Locke, and Merrill Formations, Ecm Ecm (Opf); Jones Basalt (Oj); and Tm2 and Tm3 units of Morita Ranch (Od); and older volcanic rocks of Davis and Barilla Mountains, El ၧu Formation (possibly from caldera in Cienega Mountain area) (Omr) including Sheep Pasture, Sleeping Lion, Frazier Canyon, Adobe Es Cook Mountain Formation Canyon, and Limpia Formations, Gomez Tuff, Star Mountain Home Creek Limestone and Colony Creek Shale, undivided (ၧhc); Rhyolite, and Huelster Formation (Ed) Laredo Formation (El); Cook Mountain Formation (Ecm); Ranger Limestone and Placid Shale, undivided (ၧrp); Ranger and Sparta Sand (Es) Limestone (ၧr); Winchell Limestone (ၧw); Wolf Mountain Shale (ၧwm); Es ၧh Cedarton Shale and Adams Branch Limestone, undivided (ၧca); ၧ ၧ ၧ Ew Sparta Sand Ventioner Formation ( v); Canyon Group, undivided ( cn); Palo Pinto ( pp), Schiebout, J.A., Rigsby, C.A., Rapp, S.D., Hartnell, J.A., and Standhardt, ၧ ၧ Eep and Mineral Wells ( mw) Formations; Palo Pinto ( pp) and Mineral Wells, B.R., 1987, of the -Tertiary and - Haymond Formation ၧ ၧ ၧ undivided ( pm); Jasper Creek Formation ( jc); Chico Ridge Limestone ( cr); Eocene transition rocks of , Texas: Jour. Eqc ၧ ၧ ၧ Willow Point ( wp), Brazos River ( br), and Mingus ( m) Formations; Geol., v. 95, p. 359–371. Ew ၧ ၧ Atoka Series pre-Brazos River Rocks, undivided ( pb); Grindstone Creek expanded ( gr), El Pico Clay (Eep); Weches Formation (Ew); and Queen City Sand (Eqc) ၧ ၧ and Lazy Bend ( lb) Formations; unnamed Pennsylvanian rocks ( u); K–Ar ages from: Weches Formation ၧ and Strawn Group, undivided ( st) Henry, C.D., and McDowell, F.W., 1986, of magmatism in the Tertiary volcanic field, Trans-Pecos Texas, in Price, J.G., and Eb Er Eqc ၧsw others, eds., Igneous geology of Trans-Pecos Texas: The University of Texas at Austin, Bureau of Economic Geology Guidebook 23, Bigford (Eb) and Reklaw (Er) Formations p. 99–122. Queen City Sand ၧd Smithwick Formation Henry, C.D., McDowell, F.W., Price, J.G., and Smyth, R.E., 1986, Ec Dimple Formation Compilation of potassium-argon ages of Tertiary igneous rocks, Er ၧ mf Trans-Pecos Texas: The University of Texas at Austin, Bureau of Carrizo Sand Economic Geological Circular 86-2, 34 p. Ec Marble Falls Limestone Morrow Series EPAin EPAwi ၧMt EPAc MD Indio Formation (EPAin); and , undivided (EPAwi) PA s EPAwi EPAu Barnett Formation, Chappel Limestone, Houy, Zesch, Bear Spring, MDh MDc and Stribling Formations, and Pillar Bluff Limestone, undivided UM&L PAh MISS. &

° Mi. & Dev.

27

PAw Ss+ PAmi PROVINCE NO. 4 PROVINCE NO. 3 Sf MDO PAk PAmi PAk Pal Starke Limestone WESTERN PART OF TRANS-PECOS TEXAS EASTERN PART OF TRANS-PECOS TEXAS AND HIGH PLAINS Middle Kincaid Formation (PAk); and Midway Group, undivided (PAmi) Reklaw Formation (Er); Carrizo Sand (Ec); Calvert Bluff (EPA c),

x Simsboro, (PAs), and Hooper (PAh), Formations; Wilcox Group, undivided (EPAwi); Ob Pof Pobo Wills Point (PAw), and Kincaid (PAk), Formations; Midway Group, undivided (PAmi); and 27° Om Reklaw Formation, Carrizo Sand, and Wilcox and Midway Groups, undivided (EPAu) Burnam Limestone Fingers Formation (Pof); and bolson deposits (Pobo)

Middle O Upper & Pliocene Oh Kkc Kke -M-t Kna OၤeOၤ Honeycut Formation Kns Tarantula Gravel Kes Knb Knb Miocene Kne ၧ Paleozoic rocks, undivided (Pal); Tesnus Formation ( Mt); Helms Shale, Og Knt Knm K Rancheria Formation, Las Cruces Limestone, Percha Shale, and Ehh Kmb Canutillo Formations, undivided (MDh); Fusselman (Sf), and Montoya (Om), Gorman Formation Dolomites; Missisippian, Devonian, and Ordovician rocks, undivided, (MDO); Hannold Hill Member (Kes); and and Kpg Caballos Novaculite and Maravillas Chert, undivided, (MDc); Eocene Ordovician rocks, undivided (O); El Paso Formation and Bliss Sandstone, Marlbrook Marl, undivided (Knb) Kwc Kan

Lower Ordovician Ot undivided (Oၤe); and Woods Hollow Shale, Fort Pena Formation, PAbp Ko Alsate Shale, Marathon Limestone, and Dagger Flat Sandstone, undivided (Oၤ) Tanyard Formation Kol Kpg Black Peaks Member Navarro and Taylor Groups, undivided (Knt); Navaro Group and Marlbrook Marl, Ki undivided (Knb); Kemp Clay and Corsicana Marl, undivided (Kkc); Kemp Clay (Kke); Tornillo Formation Ksm Kac ၤs Nacatoch Sand (Kns); Navarro Group, undivided (Kna); Neylandville and Paleocene

PAKj Marlbrook Marls, undivided (Knm); Neylandville Marl (Kne); Marlbrook Marl (Kmb); Kuc ၤpw Kpi Kau Pecan Gap Chald (Kpg); Wolfe City Sand (Kwc); Ozan Formation (Ko); Annona Chalk (Kan); and Upper Cretaceous rocks, undivided (K) Kag Wilberns Formation showing San Saba Member (ၤs), and Point Peak, Ksc Kg K Kg Morgan Creek Limestone, and Welge Sandstone Members, undivided, (ၤpw) Kp Kau Olmos (Kol) and San Miguel (Ksm) Formations; Upson Clay (Kuc); Koj Kbo Kgc Kbo Anacacho Limestone (Kac); Pecan Gap (Kpg) and Austin (Kau) Chalks; and igneous rocks of Austin age (Ki) Upper ၤlc El Picacho Formation (Kpi); San Carlos Sandstone (Ksc); Ojinaga (Koj), Javelina Member of Tornillo Formation (PAKj); Aguja (Kag) and Pen (Kp) Formations; Upper Cretaceous Paleocene EoceneKbr Oligocene Miocene and Boquillas (Kbo) Formations; Gulfian rocks, undivided (Kg); and Austin Chalk (Kau); (Kbo); and Gulfian rocks, undivided (Kg) ၤh Cretaceous rocks, undivided (K) Kau Kbl K

Riley Formation showing Lion Mountain Sandstone and Cap Mountain Upper Cretaceous Kbn Limestone Members, undivided (ၤlc), and Hickory Sandstone Member, (ၤh)

Middle Ker Cambrian Kbu Kbb Kbe Kbd Kbu Kbd Kda Kw Austin Chalk (Kau); Gober Chalk and Roxton Limestone (Kgc); ၤ p vh pၤy Key Klp Kbh Kse Kbh Kse Kdc Brownstown Marl (Kbr); Blossom Sand (Kbl); Bonham Formation (Kbn); Kdk Ector Chalk (Ker); and Upper Cretaceous rocks, undivided (K) Kwfr Van Horn Sandstone Younger granitic intrusion Khf Kb Ksu Kst Kki Kc Kbo Kef Kbf Kf Kpt Kfr Kdp Kef Kem Kef Kf Kdm Ked Kcp Keb Kew pၤg pၤt K Kwb Kcx Kc K Kbu Kbd Ksh Kbi Ktb Kt Kgr Ka Granite Town Mountain Granite Kgr Kdr Kbd

Kgm CRETACEOUS Kcg Kbm Kye Buda Limestone (Kbu); Buda Limestone and , undivided (Kbd); Boracho (Kbh), Kse Ksa and Finlay (Kf) ; Santa Elna Limestone, Sue Peaks Formation, Del Carmen Limestone, Kpw Kwu Kpd pၤry pၤr Kpr Kdg Kyu and Telephone Canyon Formation, undivided (Kst) Santa Elena Limestone (Kse); Sue Peaks Ked Kgt formation, Del Carmen Limestone, and Telephone Canyon Formation, undivided (Kpt); Ksu Kmk Kdv Rhyolite Kwf Kwl Kdc Kfd Red Mountain Gneiss Fredericksburg Group and Maxon Sandstone, undivided (Kem); Washita (Kw) and Ket Fredericksburg (Kfr) Groups; Washita and Fredericksburg Groups, undivided (Kwfr); Duck Creek Kdm Kwn Kcp Kea Kcw Limestone (Kdc); Kiamichi Formation (Kki); Duck Creek Limestone and Kiamichi Formation, Kec Kfu Kki pၤla pၤh pၤb Kto undivided (Kdk); Edwards Limestone (Ked); Comanche Peak Limestone (Kcp); Dakota Kfr Kpgr Kpa Kca Formation (Kda); Dakota and Purgatoire Formations, undivided (Kdp); Bissett Conglomerate (Kbi); Kgr Kwa Kgw ၤ ၤ Ka Llanoria Quartzite (p la); and Hazel Formation (p h) Big Branch Gneiss Buda Limestone (Kbu); Buda Limestone and San Martine Member of Boracho Maxon Sandstone and Bissett Conglomerate, undivided (Ktb); Maxon Sandstone and Kh Lower Cretaceous Ktp Ktm Limestone, undivided (Kbb); Buda Limestone and Eagle Mountains Sandstone, Glen Rose Limestone, undivided (Kt); Glen Rose Limestone (Kgr); Antlers Sand (Ka); and Eagle Ford Formation and Buda Limestone, undivided (Keb); Eagle Ford undivided (Kbe); Buda Limestone and Del Rio Clay, undivided (Kbd); Boracho Comanchean rocks, undivided (Kc) Formation (Kef); Eagle Ford and Woodbine Formations, undivided (Kew); pၤmc pၤa pၤc and Finlay Limestones, undivided (Khf); Espy Formation (Key); Loma Plata (Klp), Boquillas (Kbo) and Eagle Ford (Kef) Formations; Buda Limestone (Kbu); (Kwb); Del Rio Clay and Georgetown Limestone, Boracho (Kbh), and Santa Elena (Kse) Limestones; Benevides Formation (Kb); Del Rio Clay (Kdr); Buda Limestone and Del Rio Clay, undivided (Kbd); undivided (Kdg); Buda Limestone and Del Rio Clay, undivided (Kbd); Mundy Breccia and Castner Limestone, undivided (pၤmc); Coal Creek Serpentinite Finlay Limestone (Kf); Benevides Formation and Finlay Limestone, undivided (Kbf); Santa Elena Limestone (Kse); Salmon Peak Limestone (Ksa); Sue Peaks Grayson Marl and Main Street Limestone, undivided (Kgm); Georgetown and Alamoore Formation (pၤa) Sue Peaks Formation (Ksu); Del Carmen Limestone (Kdm); Cox Sandstone (Kcx); Formation (Ksu); McKnight Formation (Kmk); Del Carmen Limestone (Kdm); Limestone (Kgt); Pawpaw Formation and upper limestone unit of Weno Shafter Formation (Ksh); Glen Rose Limestone (Kgr); Campagrande (Kcg), West Nueces Formation (Kwn); Devils River (Kdv), Edwards (Ked), and Limestone, undivided (Kpw); lower part of Washita Group (Kwl); undivided Grenville Series Bluff Mesa (Kbm), Yearwood (Kye), Yucca (Kyu), and Presidio (Kpr) Formations; Comanche Peak (Kcp) Limestones; Hensell Sand (Kh); Glen Rose Limestone (Kgr); pၤs pၤm part of Washita Group (Kwu); Duck Creek Limestone (Kdc); Pawpaw pၤi Etholen Conglomerate (Ket); Torcer Formation (Kto); Comanchean rocks, undivided (Kc); Paluxy Sand (Kpa); Travis Peak Formation (Ktp); Twin Mountains Formation (Ktm); Formation, Weno Limestone, and Denton Clay, undivided (Kpd); Fort Worth and Cretaceous rocks, undivided, (K) Edwards Limestone and Antlers Sand, undivided (Kea); Comanche Peak Mafic igneous rocks Limestone and Duck Creek Formation, undivided (Kfd); Fredericksburg Group Carrizo Mountain Group showing metaigneous rocks (pၤi), Limestone and Walnut Clay, undivided (Kcw); Antlers Sand (Ka); and (Kfr); Edwards and Comanche Peak Limestones, undivided (Kec); Walnut Clay (Kwa); and metasedimentary rocks (pၤs) () CAMBRIAN ORDOVICIAN SILURIAN Comanche Peak Limestone, Walnut Clay, and Antlers Sand, undivided (Kca) undivided parts of Washita and Fredericksburg Groups (Kwf); undivided part of

Lower Cretaceous Fredericksburg Group (Kfu); Kiamichi Formation (Kki); Goodland Limestone and pၤp Jm Jmo Walnut Clay, undivided (Kgw); and Upper Cretaceous rocks, undivided (K) Fault—Ball shows downthrown side

Packsaddle Schist Malone Formation

Upper Thrust Fault—Barbs on overriding plate JURASSIC CRETACEOUS TERTIARY pၤl ၣc Kpa Manuscript geologic map by E.W. Collins, Bureau of Economic Geology, The University of Texas at Austin used for Georgetown—Round Rock area, Lost Creek Gneiss ၣ ၣ Kgr Ka j d Williamson County, Texas

ၣv Ktm *Lingos reference: pၤv

TRIASSIC Kcs Caran, S.C., and Baumgardner, R.W., Jr., in press, Quaternary stratigraphy Chinle (ၣc), Trujillo (ၣj), and Tecovas (ၣv) Formations Paluxy Sand (Kpa); Glen Rose Limestone (Kgr); Twin Mountains and paleoenvironments of the Texas Rolling Plains: Geological Society Upper Valley Spring Gneiss and Dockum Group, undivided (ၣd) Cow Creek Limestone, , and Sycamore Sand, undivided Formation (Ktm); and Antlers Sand (Ka) of America Bulletin.

106° 105° 104° 103° 102° 101° 100°

Lambert Conformal Conic projection SCALE 1:500 000 Geologic map database of Texas by Stoeser, D.B., Shock, N., 1927 North American Datum 10 0 10 20 30 40 MILES Green, G.N., Dumonceaux, G.M., and Heran, W.D. Any use of trade names is for descriptive purposes only and 10 0 10 20 30 40 50 KILOMETERS does not imply endorsement by the U.S. Government TEXAS GIS and PDF files are available online at NORTHWEST http://pubs.usgs.gov/ds/2005/170/ QUADRANT (Plate 2) NORTHEAST QUADRANT Southwest Quadrant (Plate 1)

SOUTHEAST GEOLOGIC MAP OF TEXAS QUADRANT (Plate 4)

SOUTHWEST QUADRANT Compiled by (Plate 3) Virgil E. Barnes

1992 MAP LOCATION