CENOZOIC Quaternary A lluvium and co lluvium avel, pediment , and fan depo s it s Glacial depo s it s Lands lide depo s it s Dune sand and lo ess Sur ficial depo s it s , undiffer ent iat ed Quaternary and Tertiary Ter ace gr avel Tertiary U pper Mio cene r o ck s Lower Mio cene r o ck s Mio cene and upper Oligo cene r o ck s o r r o ck s equivalent t o upper and lower Mio cene r o ck s and W hit e R iver Fo r mat ion W agon Bed Fo r mat ion W hit e R iver Fo r mat ion U pper conglomer at e member I nt r usive and ext r us ive igneous r o ck s–inco r po r at es masses o f Miss iss ippian t hr ough Cambr ian fo r mat ions asat ch Fo r mat ion Moncr ief Member Kingsbur y Conglomer at e Member Union Fo r mat ion Tongue R iver Member Tongue R iver and Lebo Member s Lebo Member Lebo and Tullo ck Member s Tullo ck Member MESOZOIC Cretaceous Lance Fo r mat ion Lance Fo r mat ion, Fox Hills Sands t one, Meet eet se Fo r mat ion, and Bear paw and Lew is Shales Hills ands t one Hills ands t one and Lew is Shale Hills ands t one and Bear paw Shale Mesaver de Fo r mat ion Cody Shale P ier e Shale Niobr ar a Fo r mat ion Niobr ar a Fo r mat ion and Car lile Shale Car lile Shale eenho r n Fo r mat ion and Belle Four che Shale Kgbm Gr eenho r n Fo r mat ion, and Belle Four che and Mowr y Shales F r ont ier Fo r mat ion ier Fo mat ion, and Mowr y and Ther mopo lis Shales Mowr y Shale Mowr y and Ther mopo lis Shales Newcas t le S ands t one and Skull C r eek Shale Lew is Shale Cretaceous and Jurassic lover ly Fo r mat ion ( Har t ville U plift ) o r Inyan Kar a Gr oup ( B lack Hills) and Mo r ison Fo r mat ion lover ly, Mo r ison, and Sundance Fo r mat ions lover ly, Mo r ison, Sundance, and Gypsum Spr ing Fo r mat ions Jurassic Sundance Fo r mat ion Sundance and Gypsum Spr ing Fo r mat ions Triassic Chugw at er Fo r mat ion Chugw at er and Dinw ody Fo r mat ions MESOZOIC AND PALEOZOIC Chugw at er and Go se Egg Fo r mat ions Go se Egg Fo r mat ion Spear fish Fo r mat ion MzP z Meso zo ic and P aleo zo ic r o ck s , undiffer ent iat ed PALEOZOIC Permian P ho spho r ia Fo r mat ion and r elat ed r o ck s Minnek aht a L imes t one and Opeche Shale Permian and Pennsylvanian Casper Fo r mat ion Har t ville Fo r mat ion–low er mo s t unit may be Lat e Miss iss ippian m Minnelusa Fo r mat ion Permian, Pennsylvanian, and Mississippian Tens leep S ands t one and Amsden Fo r mat ion M Casper Fo r mat ion and Madison L imes t one Mississippian Madison L imes t one o r Gr oup–includes w edge edge o f B igho r n Do lomit e in Tps . 43 and 4 N . , R gs . 85 and 86 W Mississippian and Devonian Madison L imes t one and Dar by Fo r mat ion P ahasapa and Englewod L imes t ones MDg Guer nsey Fo r mat ion–lo cally includes do lomit e and sands t one o f Devonian and Cambr ian( ? ) age Mississippian and Ordovician Madison L imes t one and B igho r n Do lomit e–eas t s ide o f B igho r n Mount ains Mississippian, Devonian, Ordovician, and Cambrian Minnek aht a L imes t one, Opeche Shale, Minnelusa Fo r mat ion, P ahasapa and Englewod L imes t ones , W hit ewod Do lomit e, and W innipeg and Deadwod Fo r mat ions–var ious combinat ions Ordovician igho r n Do lomit e Ordovician and Cambrian B igho r n Do lomit e, Gallat in L imes t one, Gr o s V ent r e Fo r mat ion, and F lat head S ands t one Cambrian Gallat in L imes t one, Gr o s V ent r e Fo r mat ion and equivalent s , and F lat head S ands t one PRECAMBRIAN =u Pr ecambr ian r o ck s , undiffer ent iat ed Ob O_ _u =u 104°0'W 104°30'W 104°30'W 105°0'W 105°0'W 105°30'W 105°30'W 106°0'W 106°0'W 106°30'W 106°30'W 107°0'W 107°0'W 107°30'W 107°30'W 45°0'N 45°0'N 44°30'N 44°30'N 44°0'N 44°0'N 43°30'N 43°30'N 43°0'N 43°0'N 42°30'N 42°30'N Scale 1:350,000 WYOMING STATE GEOLOGICAL SURVEY Thomas A. Drean Director and State Geologist Laramie, Wyoming Map Projection: Lambert Conformal Conic False Easting: 500000, False Northing: 200000 Central Meridian: -107.5 degrees West Standard Parallel 1: 41 degrees North Standard Parallel 2: 45 degrees North Latitude of Origin: 41 degrees North Linear Unit: Meter Horizontal Datum: North American Datum of 1983 (NAD 83) Ellipsoid: Geodetic Reference System 80 GEOLOGIC MAP OF THE POWDER RIVER BASIN, WYOMING DISCLAIMERS U ser s o f t hese maps ar e caut ioned agains t using t he dat a at scales differ ent fr om t ho se at w hich t he maps w er e compiled. Us ing t his dat a at a lar ger scale will no t pr ovide gr eat er accur acy and is , in fact , a misuse o f t he dat a. The W yoming S t at e Geo logical Sur vey ( W SGS ) and t he S t at e o f W yoming mak e no r epr esent at ion o r w ar ant y, expr essed o r implied, r egar ding t he use, accur acy, o r complet eness o f t he dat a pr esent ed her ein, o r o f a map pr int ed fr om t hese dat a. The act o f dis t r ibut ion shall no t cons t it ut e such a w ar ant y. The W SGS do es no t guar ant ee t he digit al dat a o r any map pr int ed fr om t he dat a t o be fr ee o f er o r s o r inaccur acies . The W SGS and t he S t at e o f W yoming disclaim any r espons ibilit y o r liabilit y fo r int er pr et at ions made fr om t hese digit al dat a o r fr om any map pr int ed fr om t hese digit al dat a, and fo r any decis ions based on t he digit al dat a o r pr int ed maps . The W SGS and t he S t at e o f W yoming r et ain and do no t w aive sover eign immunit y. The use o f o r r efer ence t o t r ademar ks , t r ade names , o r o t her pr o duct o r company names in t his publicat ion is fo r descr ipt ive o r info r mat ional pur po ses only, o r is pur suant t o licens ing agr eement s bet w een t he W SGS o r S t at e o f W yoming and so ft w ar e o r har dw ar e developer s / vendo r s , and do es no t imply endo r sement o f t ho se pr oduct s by t he W SGS o r t he S t at e o f W yoming. NOTICE TO USERS OF INFORMATION FROM THE WYOMING STATE GEOLOGICAL SURVEY The W SGS encour ages t he fair use o f it s mat er ial. W e r eques t t hat cr edit be expr essly given t o t he “ W yoming S t at e Geo logical Sur vey” w hen cit ing info r mat ion fr om t his publicat ion. P lease cont act t he W SGS at 307 - 76 - 286 , ext . 24 , o r by email at w sgs . sales@w yo . gov if you have ques t ions about cit ing mat er ials , pr epar ing ack nowledgment s , o r ext ens ive use o f t his mat er ial. W e appr eciat e your coper at ion. I ndividuals w it h disabilit ies w ho r equir e an alt er nat ive fo r m o f t his publicat ion should cont act t he W SGS . Fo r t he TTYr elay oper at o r call 1 - 80 - 87 - 97 5 . Fo r mo r e info r mat ion about t he W SGS o r t o o r der publicat ions and maps , go t o www. w sgs . uw yo . edu, call 307 - 76 - 286 , ext . 24 , o r email w sgs . sales@w yo . gov. EXPLANATION Geology - Interpreting the past - providing for the future GEOLOGIC UNITS (Geology enlarged from 1:500,000 scale to improve readability) 0 10 20 30 40 50 Miles 0 20 40 60 80 Kilometers Qa Qt Qg Qls Qs Qu QTg Tmu Tml Tmo Twb Twr Twru Tie Kl Klm Kfh Kfl Kfb Kp Kmv Kc Knc Kcl Kgb Kf Kft Kgbm Kmr Kmt Kns KJ KJg KJs Kn Js Jsg ^c ^cd ^Ps ^Pcg ^Pg MzPz Pp Pmo P*c Pzr P*h P*m P*M PM Mm MD MDe MDg MO MAP SYMBOLS DATA REFERENCE Love, J . D . , and Chr is t iansen, A . C . , comps . , 1985 , Geo logic map o f W yoming: U. S . Geo logical Sur vey, 3 sheet s , scale 1 : 50 , 0 . BASE MAP REFERENCES Bur eau o f I ndian Affair s , 2 05 , Boundar ies— I ndian Lands , R aw Dat a R elease, December , 20 5 : Nat ional A t las o f t he U nit ed S t at es , at ht t p: / / nat ionalat las . gov/ . Bur eau o f Land Management , 201 , Cadas t r al Nat ional Spat ial Dat a I nfr as t r uct ur e ( CadNSDI ) P ublic Land Sur vey Syst em ( P LSS ) fo r W yoming, at ht t p: / / www. geo communicat o r . gov/ geo comm/ ls is_home/ home / index. ht m. Nat ional Oceanic and A t mo spher ic Adminis t r at ion, 1985 , D igit al magnet ic declinat ion: Nat ional Geophysical Dat a Cent er , at ht t p: / / www. ngdc. no aa. gov/ geomagmodels / s t r ut s / calcDeclinat ion. S t o eser , D . B . , Gr een, G . N . , Mo r at h, L . C . , Her an, W . D . , W ilson, A . B . , Mo r e, D . W . , and V an Go sen, B . S . , 205 , Pr eliminar y int egr at ed geo logic map dat abases fo r t he U nit ed S t at es—Cent r al s t at es—Mont ana, W yoming, Co lo r ado , New Mexico , No r t h Dako t a, Sout h Dako t a, Nebr aska, Kansas , Ok lahoma, Texas , Iowa, Missour i, Ar kansas , and Louis iana: U. S . Geo logical Sur vey Open- F ile R epo r t 20 5 - 1351 , 18 p. U. S . Census Bur eau, 196 , C it ies , t owns , census des ignat ed places o f W yoming at 1 : 10 , 0 , at ht t p: / / w ygl. w ygisc. o r g/ w ygeo lib/ cat alog/ main/ home. page. U. S . Census Bur eau, 197 , W yoming r o ads at 1 : 10 , 0 , at ht t p: / / piney. w ygisc. uw yo . edu/ dat a/ t r anspo r t at ion/ r o ad10k. z ip. U. S . Geo logical Sur vey, 202 , The Nat ional E levat ion Dat aset : P ho t ogr ammet r ic Engineer ing and R emo t e S ensing, v. 68 , no . 1 , at ht t p: / / ned. usgs . gov. W yoming Geogr aphic I nfo r mat ion S cience Cent er , 197 , I nt er net mapping ser vice—Basemap dat a fo r W yoming: Spat ial Dat a and V isualiz at ion Cent er , at ht t p: / / w ygl. w ygisc. o r g/ w ygeo lib/ cat alog/ main/ home. page. BASIN LOCATION MAP Edited by Phyllis A. Ranz and Suzanne C. Luhr Digital cartography and layout by Suzanne C. Luhr Geology modified from Love and Christiansen (1985) Kle Formation contact Normal fault —Do t t ed w her e concealed; ball and bar on do w nt hr own blo ck ; no des ignat ion on fault t r ace indicat es undet er mined mo t ion Thrust fault —Do t t ed w her e concealed; sawt eet h on upt hr own ( t ect onically higher ) blo ck : ( ( Magnet ic Declinat ion = 9 ° 38 ' E at cent er o f map ( Feb. 12 , 2013 ) N MN Count y boundar y S t at e boundar y C it y o r t own Count y seat _ U Lake o r r eser vo ir Int er st at e highw ay U. S . highw ay S t at e highw ay Count y o r o t her r o ad § ¨ ¦ 80 ( / 30 ! ( 89 " ) 1 Twmo Tw Twk Tfu Tftr Tftl Tfl Tflt Tft MONTANA SOUTH DAKOTA NEBRASKA