/ . Descriptive Geology, 91 Professional P~per No. 53 Senes {B, 0, Underground Waters, 57 DEPARTMENT OF THE INTERIOR ,UNITED , . STATES GEOLOGICAL SURVEY CHARLES D. WALCOTT, DIRECTOR GEOLOGY AND 'VATER RESOURCES OF THE BIGHORN BASIN, WYOMING BY CASSIUS A. FISHER WASHINGTON G'OVEI~N:MENT PHIN'TING OFFICE 1906 .r.!J -7, '3 tl ~ -8'-'1~ no, ~- 3 C/ I : .l ~\ 72 3656 3 09 CONTENTS. Page. Introduction. ____________ _-- - - - -- - - -- -- - - - - - _ - ___ ------------------ ___ - ___ ------- ' -------- __ 1 Topography ___________________ ---- -- -- -- -- __________ -- -- -- -- -- -- -- -- -- ___ - -- -- -- -- -- -- ____ _ 1 General relations. ____________ ------- ___________________________________________________ _ 1 Relief. _________________ - _ -- -- ---------- -- -- -- ------ ---- ------ -- ------ ---- ---- ---- ---- - 2 Bighorn Mountain region ___________________________________________________ _ 2 Bridger and Owl Creek mountains_, ________________________ , __________________ _ 3 Absaroka and Beartooth.mountains __________________________________ , ________ _ 3 Shoshone Mountains ________________________________________________________ _ 3 Sheep Mountain region. ____________________________________________________ _ 4 Bighorn basin region _______________________________________________ , ______ _ 4 Drainage. _____ -- - _ -- - - -- -- -- -- -- -- - ___________ -- -- -- - _ -- -- -- -- -- -- - ___________________ _ 5 Bighorn River ____________ : ________________________________________________ _ 5 Shoshone River. ___________________________________________________________ _ 6 Gray Bull River ___________________________________________________________ _ 6 Clark Fork. _______________________________________________________________ _ 7 Other important streams. __________________________________________________ ~ _ 7 Outline of the geology---- - _ -- -- -- -- -- -- - _________ - _ -- -- -- -- -- -- -- -- -------- -- -- -- -- - _ -- - _ - __ 8 Stratigraphy ________________________________________ .- _________________________________ _ 8 Pre-Cambrian rocks ____________ -- ____________________ -- __ ------ ____________________ _ 9 Granite _______________________________________________________________________ _ 9 General statement _______________________ " _________________________________ _ 9 Granites of the Bighorn Mountain region. _______________________________ . ______ _ 9 Dikes of the Bighorn Mountain region. _______________________________________ _ 9 Granite and diabase of Rattlesnake Mountain _________________________________ _ 10 Granite of Owl Creek Mountains _____________________________________________ _ 10 Cambrian system __________________________________________________________________ _ 10 Dcadw.;lOd formation. __________________________________________________________ _ 10 General relations. ________________________________ ·__________________________ _ 10 Absaroka Mountain region __________________________________________________ _ 10 Bighorn Mountain region ___________________________________________________ _ 11 Owl Creek Mountain region ______________________ -·- _________________________ _ 11 Ordovician system. ___ -.- ___________________________________________________________ _ 12 Bighorn limestone. ____________________________________ ; ________________________ _ 12 General relations. ________________________________ : _________________________ _ 12 Absaroka Mountain region __________________________________________________ _ 12 Bighorn Mountain region ___________________________________________________ _ 12 Carboniferous system. ____________ , _________________________________________________ _ 13 Madison formation. ____________________________________________________________ _ 13 General relations:-_---- - ___________________________________________________ _ 13 .. Absaroka Mountain region __ ~ _______________________________________________ _ 14 Bighorn Mountain region ___________________________________________________ _ 14 . -Owl Creek Mountain region. ________________________________________________ _ 14 . III TECHNICAL LlBRARY .' BONNEVILLE POWER ADMINISTRATION IV CONTENTS. Outline of the geology-continued. • Page. Stratigraphy-continued. Carboniferous system-Continued. Amsden formation ............................................................ _ _ 15 General relations .. __ .... ______ .. _____ ..... ______ .... _ . , ____________________ _ 15 Absaroka Mountain region .. _... __ .. __ ............... __ .......... _........... _ 15 Bighorn Mountain region ....... _.... __ . __ ............. __ .... __ .. _. ___ ..... __ 15 Owl Creek Mountain region ... _.. _ ........ _................ _ .. _"_ .... __ ...... 16 Tensleep sandstone .... _... __ ....... ~ .. ___ .. _____ .... __ ·___ .. _______________ .. ___ _ 16 General relations.................... _.. ______ , ....... _. ______ . ________ ·_____ _ 16 Absaroka Mountain region .............................. _......... _........ __ 16 Bighorn Mountain region ... _........ _.. ______ .. _... ________ . ______________ . _ 16 Owl Creek Mountain region .. __ .......... _ . _ ....... ___ .. ______________ . ____ . _ 17 Embar formation .............. _... _..................... _. _... ___ .. _____ . __ . _.. 17 I General relations................ __ . _.............................. _. ______ .. 17 Rattlesnake and Cedar mountains ..... __ ..................... __ .............. 17 Triassic system ( 1) ____ .. -. __ ............... __ ... ______________________________ . __ . __ _ 18 Chugwater formation ...................... : . ............ __ . ____ . _ ... ______ . ___ .. 18 General relations.......... _ ............................ _................... 18 Distribution ................................................ _............... 18 Local stratigraphy................ _ ............ ·.... _... ______ .• __ :, .-, _____ . _ Hi Age of the formation ................................... , ..... _......... _... 21 Jurassic system ................................................................... __ 21 Sundance formation .................................. _.... · ...... __ ........ _.... 21 General relations ........................................................... 21 Absaroka Mountain region ........................... __ .... ____ ............ __ 21 Bighorn Mountain region ........ _.................. __ .. _____ . _______ . _..... _ 23 Cretaceous system ............................... _.............. ____ . _________ .'. ___ _ 25 Morrison formation ............ _..................... __ . _.......... __ . __________ _ 25 General relations .. __ ..........· ..... __ ........ __ ..... __ . _. _........ _ . ____ ... _ 2.5 Absaroka and Owl Creek Mountain region ..... ,....... , ......... _............... 2.5 Bighorn Mountain region ...................................... _ . ~ .......... 26 Cloverly formation ...•......... ' ............................. _....... ___ . __ . _ .. _ 26 General relations .. ____ ..................... __ ...............•.. __ ~ ......... 26 Absaroka Mountain region ................. ·................................. 27 Bighorn Mountain region ......................... _. _. _..... ___ ... _......... 27 Owl Creek Mountain region ................................. __ .... ___ . _..... 28 Colorado formation ............................................... _... _.. ____ . __ _ 28 General relations ................................................. ___ . _.. _ .. _ 28 Pryor Mountai~ region .... ~ ............ __ ........................ ~-- ........ 29 Absaroka Mountain region ...................... , ........................... 29 Bighorn Mountain region .......................... , ........................ _ 29 Sandstone dikes ....................................... _. ______ ............ 30 Pierre shale .......................................... __ . __ , _. _... _..... _.. _ . ___ _ 30 Character and thickness .................................................... 30 Distribution ......... __ .................................... __ .. __ ...... __ .. 30 Laramie and associated formations ............................. __ ................ 31 General statement ......................................................... 31 Stratigraphy.............................................................. 31 Age of the formations ...................................................... 32 Supposed Fou Hills sandstones .............................................. 32 Tertiary system .................... _............................................... 32 Volcanic and associated sedimentary rocks .............. __ ........................ 32 Wasatch formation ............................... ·.............................. 33 Character and thickness .............•....................................... 33 Distribution ...................•.••••••••••................................. 33 \ CONTENTS. v Outline of the geology-Continued. Page. Stratigraphy-Continued. Quatern!Lry system ........... _____ .....•...•.... _ .. ______ ... _................. ·_ .... 34 General statement. ____ . ___ . _ ..... _ ..... __________ ....... ' ................. 34 Early terrace gravels.... ___ ............. ___ ... _ ............................ 34 Later terrace gravels. ______ . ___________________________ .. _...... ___ ... ___ .. 34 Alluvium. ______ . __ . ___________ ~ ____________________ . ___________ . ____ . ____ _ 35 Structural geology ..... _..... __ .. ____________ . _______________________________ . ___ . _____ _ 36 General features. ___________________________