(,:I0 ) Lake Lahontan: Geology of Southern Carson Desert, Nevada By R. B. MORRISON GEOLOGICAL SURVEY PROFESSIONAL PAPER 401 A stratigrapAic study of the Cenozoic geology of part of the hasin of Lahe Lahontan, one of thegreat - late Pleistocene lakes of IWestern United States SAG N P TJUN1I9CW 4 I UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON :1964 _21111111111111100- -0: I :_i4} CONMENTS ' Abtat--rt _, ___ _ _ ,_.t____ _,_,___ __ Quaterusry str itgraphy-CeotinUet 1sgo lntroducdon. ------------ ---------------.---- _-o--- 2 aontan Valley grousp-Contlotied Location _---_ --------------. 2 Eetaa formation--Conatnued 30 Fieldwork ._------------------------ 3 Shore features.-------------.----- Acknowledgments . ....... 4 Tuts. _._ _ _ _ _ _ _ _ _ _...... 31 Previous work ............................. 4 IntraEetza lake recension............. 31 Geographic setting ..... ... ......... 4 LAke sand, lot, and clay .------.------ 33 Major lhndforms ................... 5 Correlation with deposits of Lake LAbontan CarsonDesert and adjoining bsins ...... S described by Russell and Antlef. _-____ 33 Highlands bordering the basins. ... a Paleontology .----------- 33 Climate .------------ - .. 5 Alluvial gravel and oolluvium of Eets a*ge.___ 33 UNITED STATES DEPARTMENT OF THE INTERIOR Wyemasa formation .... ,,.,__. ______ 34 Vegetation .-------- .- 7 General features .-------- __-_-__._____ 34 STEWART L. UOALL, Secretary Economic geography .--------------.-.-.--- a Correlation with deposits of Lake Lahontan Tertiary stratigraphy and structure . ,,_ a described by Russell And Anteva . 34 Stratigraphy .. ---------- 9 Eollhn sand. _------,,,___---.... 34 GEOLOGICAL SURVEY Basalt of Rainbowvlountain _-_-_-.-. _ 9 Allusini and colluvini gravel and ssnd .... 3S Dacnteof Rainbow rountsin 10 Interbedded shallow.lake and subaerial 10 Thomas B. Nolan, Director Engles House rbyolite __-_-.- _-_-_ sediments. _ ------------------- 36 Truckee formatbo. _ .__- ------ ill Subsurface basin sediments. 37 BuneJug formatlon . 12 Paleontology.--------------------------- 38 Btructurat features .................. ,._.,._ 15 Basaltic tuff of Upual Hogback.- -___ 3S Tue t.s. ,eoledgetl -ryerLtbrryI ha stologed thIs pobticatl*a 55 fol-o1 : Pre-Truckee faults .................. ------- 15 Churchill soil .-------.--. ---- 38 Faults of post-Truckee and early Bunejug age-- ils General relation and distributiobn. ___ 38 Profile characterittks ....---------- Structurne features of post-BuneJug pre-Palute age._ 15 40 Baootand-range fault .. ... .. ... is Schoo formation .----.--..--..._-_-__ 41 General features . ......... _ General features .- ..- _-_--_--- 41 Faulting In specific areas... .... 16 Members. ----------- a1 ConfigurA inonof the bedrock floor of the basin... 17 Lowrermember ..------------ il Morrison, Roger Barron, 1914- Quasternary stratigraphy..........--.*------------- ilnolite unit .- ._------------- 59 Lake Lnhontan: geology of southern Carson Desert, Ne. Methods of sludy........... Dendritin member ..- __---------- 61 vada. Washington, US. Govt. PrinLt. Off., 1963. Stratigraphik uage.. Upper member ....- ------------ 62 sonils. ....................... 19 Shure features of &ehooage ------------ 63 ,. 5I p. I1us., mapls dhrn.. tables snd portfolio tfold. maps Definltion and general features ... 19 Shorelines of the early &ehoo lake .- .____ 63 (Iprt col.) dlsgr., tables) 29 M. tUS. GeologiecaSurey. Pro- Boil profiie.... ......................... 20 Compsrative heights of highest Eetus snd es'slDnal paper 401) Biliogrsphy: p. 117-121. Classieaton............ _ . 20 early sehoo shorelines at Russlcl Spit.... 64 DescriptIve terminology ..................... 21 Lake levels during deposition of the thino- 1. Ceologr-NevadsaChurebill Co. 2. Oeolory, Stratigraphir- Great soi groups ........................... 21 lite units.-------- 65 Cenonoic. 1. Tide. l1. TlIe: Carson Desert, Nevada. (Beries) Pre.LAke lAhontan erosional fatures............ 22 Shorelines of the middle Shoo lake; "den- Pre-LAke Lahoatan Quaternary steaigeaphy ...... 23 ttile terrace .......... - . - . 65 Basalt of Ralttlesske lill ............... 231 Shorelines of the late Sehoolake . 65 Pre.lAke lahontan lacustrine sediments....... 23 Indian Lakes formation......... _. __ 6S Palute formation .. ................ 23 General features . 68 Buried pre-Lake LAhontan Quaternory sedi- Tongues and age units ............ es ments.tl: ..... ............... 24 Alluvium and rolluvium above the CocoonWou .. ,,,,,,,,,,,,,,, 24 Lahontan beach.....------- 68 General featurea and relstions .--- 241 LoAvertongue ...... --------- 68 Profile oharacterLiees .. ...... 25 Middle tongue ....... 68 Age. 28 Alluvium of middle Srhoo and Indian Lhontan VaIley group. 28 Lakes age....................... 69 EelIs formation. 28 Alluvium, colluuium, and rolian sand General features..................__... 28 of Isle ihoo sad Indian Itke Age._ 71 LWkegravel . ......... 28 Voleanicand complex of Sod. L -ake. ... 71 For sale by the Superintendent of l)ocurnents, U.S. Government Printing Odice in WVashington. D.C. 20402 CNEt S coti~~~~~~~~~~~~~mers~~~~~~~~~~~CONTENTS Y rass Far. Pars Fioute 1. Mlap showing locatios of report areaand aresInundated by lake Lahontn_................................ Quaternary ateatigraphy-ConUnoued Geologs hintery ............... .. 9.i 3 - 2. Diagram of topographic and geologic positions ot prinelpal plant asociations Lahontas Valley group-Costinuad Tertisry history ------------------ _------ ...- tN a FosSils of Sehooand Indian Lakes age ... Quatetnary history* ............................... 97 3. Eaposures of Bunejug and Truckes formations In White Throne Mountains† † 13 4. Diagram showing age and stratlgraphln relations of the five main (named) lete Quaternary sils Itn Ue Cason Soils of Sehooand Indian Lakes age-....... Pre-Lake [shontan history . i97 Desert area ..._._... ...... fllatory at lake Lahoana-.. ......... Ineiplest unnamej Sni ot middle Indian 9g 5, Section through basin ot Paulte Wash ....... Lakes age ..- .----- 26 ------ * et. Uime _................ ng ........ 6. Cocoon sil. A, At type locality: R, on sloping urfaces- Harmon School sod .. il....._.... Wyesmaha 27 time .. .. P 7. Northern piedmont of Desert Mountains. .. ....................................... Turpah formation. ...----.- Churcbill Interval .. ... - ..... 100 2° _-_- 6. Gravel ot Ecta formation .................................. General featurss .... -------.---- SO Sehoo timeUrns----------- _ . 100 9, Compound high-lvel bar near RuFdellSpit. .. Eolbn sa nd..-- _------ Post-lskt Labontan history- 30 102 . 10. Aerial photograph at western LahontasnMounta ns. Turupab timesi... 102 31 Loes _. 11, Aerial views. A, High-level spits at southwest edg of Carson Desert; D, compound low-hevel apit....... Toych Interval ....... -10........ 103 32 Alluvial nand.----------- 12. Occurrences of the Wyemaha formation...... Dinconformity coeval with the Turupah Fallon time . -.. 103 33 13, Type locality for CiLtrehill soil and lower-memberoaSehooformation and lower tongue of Indian Lamsesformation. formation; evidence Deposltional history In the bhaln 'ePs; 39 of romplete lake 14. Churchill soil on allIviul gravel of the Wyermahaformation .............................................. deuIredntln Interloi .... .. 103 :W' 41 15. Eetza, Wycmraha Sehoo,and Indian Lakes formations 42 Fo&-Isi ----- ------------. - - -- Erosional and depenitlona. history In :, 16. Lithold tufa of the lower member of the Sehooformation 49 Toyrk sol. _ the highlands - 105 17. Lithoid and Corasline"tufa of the lower member of the Sehoo formation Humsn occupation -os 50 Stratigraphic relations and occurrence -' 18. Crilular tufa and thinolite Profile charactertics. Climatic history -. 106 S5 ComparIson with previous Interpretatlon 106 19. "Heads" of dendritie tufa . ..... ---...--------. --------------------------.---- 52 Fallon formation ......... -- .. 20. Dendritic tufs ahoaIng internal structure General features. Cotrelation and age of the Quoternary deposits and soils. 108 53 21. Blanket deposits of dendritie tifn at Eetna hountoin 54 Means of correlation . 108 . Lower member .- - 22. Specimenshouing lecture of tufa "branches" and speoimen*howing tufs "heads" resting on late thinolite.._ Correlation of the Cocoon, Churchill, and Toyeb 53 Upper member .------------- Z3. Eerly and lute lithoid tuba of the upper member of the Sehoo formation soils, Lahontan Valley group, and Fallon forma- 50 Luke and interlake units. 2J. Lithoid tule of the first and third lake units of the FYalonformation Uon, with late Quaternary soils and deporits in 57 Eolian sand .... 25. Geologic map of Spiltsouthwest of Bunejug Mountains ...... _ the Lake Bonneville, Sierra Nevada, and Mono 58 Alluvium. 26. Lake areas.. -110 ... Comparative columnar Sectionsof clay of the lower Sehoo 60 Colluvium. 27. Diagrammatic cross section shownIg occurrence of thinolite Lake sediments and ahore features. Comparion wsith previous correelstons of Lakes 61 Lahontan and Bonneville . 111 28. Hachure mop of Russell Spit and vicinity ...................................................... 68 Foails........... .. 29. Geologic Evidence on absolute age...----- .-.-.-.--.-.. "I map of Russell Spit and vicinity ...... _....... 07 Sols of Fallon age.. --- 30, Sand and elay or the upper nteo'ler of the Sehooand Toyeh soll. General features. General deductions on late Quaternary correlatIon, 70 31, Diagrammatic crosssection rhowing relations of the Fallon, Turupohb Sehoo, and Wyemaha formanions. 76 iLDralsn