Pleistocene Geology of Eastern South Dakota GEOLOGICAL SURVEY PROFESSIONAL PAPER 262 Pleistocene Geology of Eastern South Dakota By RICHARD FOSTER FLINT GEOLOGICAL SURVEY PROFESSIONAL PAPER 262 Prepared as part of the program of the Department of the Interior *Jfor the development-L of*J the Missouri River basin UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1955 UNITED STATES DEPARTMENT OF THE INTERIOR Douglas McKay, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price $3 (paper cover) CONTENTS Page Page Abstract_ _ _____-_-_________________--_--____---__ 1 Pre- Wisconsin nonglacial deposits, ______________ 41 Scope and purpose of study._________________________ 2 Stratigraphic sequence in Nebraska and Iowa_ 42 Field work and acknowledgments._______-_____-_----_ 3 Stream deposits. _____________________ 42 Earlier studies____________________________________ 4 Loess sheets _ _ ______________________ 43 Geography.________________________________________ 5 Weathering profiles. __________________ 44 Topography and drainage______________________ 5 Stream deposits in South Dakota ___________ 45 Minnesota River-Red River lowland. _________ 5 Sand and gravel- _____________________ 45 Coteau des Prairies.________________________ 6 Distribution and thickness. ________ 45 Surface expression._____________________ 6 Physical character. _______________ 45 General geology._______________________ 7 Description by localities ___________ 46 Subdivisions. ________-___--_-_-_-______ 9 Conditions of deposition ___________ 50 James River lowland.__________-__-___-_--__ 9 Age and correlation_______________ 51 General features._________-____--_-__-__ 9 Clayey silt. __________________________ 52 Lake Dakota plain____________________ 10 Loveland loess in South Dakota. ___________ 52 James River highlands...-------.-.---.- 11 Weathering profiles and buried soils. ________ 53 Coteau du Missouri..___________--_-_-__-___ 12 Synthesis of pre- Wisconsin stratigraphy. ____ 54 Missouri River trench.______________________ 14 Physical geology of the Wisconsin stage _________ 56 Missouri Plateau west of Missouri River_______ 15 Glacial markings. _________________________ 56 Streams ___________________________________ 16 Exposures and preservation of markings. 56 Lakes.____________________________________ 17 Polished surfaces. __ __________________ 56 Climate.______________________________________ 17 Striations and grooves____________-____ 57 Soils. _________________________________________ 18 Crescentic marks _____________________ 58 Biogeography_ _________________________________ 21 Thickness of drift__________--_-______-___- 59 Pre-Pleistocene rocks________________________________ 22 59 Stratigraphic sequence and lithology______________ 22 General character. _________________________ 59 Ease of erosion of Pierre shale.___________________ 24 Boulders. ______________--___-_-___-_-_-_-. 60 Tertiary strata, chiefly Ogallala formation _________ 24 Contorted structures. ______________________ 62 Structure._____________________________________ 26 Stratified drif t_ ____-___--_____--_-_-_-_-_--_-_. 63 Pleistocene geology.________________________________ 27 Classes ______________-_-__-___-__--_-_-_-. 63 Glaciation _____________________________________ 27 Outwash_ __ _ ______-_______-___-___-_-__-_. 63 Glacial deposits______-_____________--_-_--__-- 27 Outwash-margin lake deposits. ______________ 65 Effect of glaciers on drainage.._.___------________ 28 Glacial lake deposits. ______________________ 65 Nonglacial deposits_-__--_-_-______----___-_-___ 28 Ice-contact stratified drift_ _________________ 65 Loess. ...__________________________________ 28 Basins in the drift __ _____-_____--__-___-___-_- 67 Stream deposits.___________________________ 28 Loess. __________________-__--___---_______-_-. 68 Position and form of the bedrock surface __________ 28 Color and alteration.... ___________________ 68 Pre-Wisconsin glacial deposits _____ ___________________ 30 Stratification _ _________-__-__--_____--__- 69 Regional stratigraphic sequence__________________ 30 Structure. ___-________-__-_--_-_--__-_-__ 72 Uncertainties in correlation ______________________ 30 Thickness and topography. ________________ 72 Physical characteristics of pre-Wisconsin tills______- 31 Areal extent____ _____________ _____________ 74 Description of exposures-__-_-____-_------_------ 33 Fossil content- ____________________________ 74 Tills certainly or probably pre-Wisconsin because Grain size. _ _ _____________________________ 75 of their stratigraphic relations._____________ 33 Summary of loess characteristics. ____________ 76 Tills believed to be pre-Wisconsin on topo­ Stratigraphy of the Wisconsin deposits. ______________ 76 graphic evidenee____-_______________-_____ 38 History of stratigraphic subdivision ______________ 76 Tills believed to be pre-Wisconsin 011 internal Differentiation of drift sheets in South Dakota. __. 77 evidence. ________________________________ 39 Terminology of loess sheets ____.___-___-_-__--_. 80 Distribution of tills._____________--------___ 40 Wisconsin stratigraphy inferred from well logs____. 81 Other possible pre-Wisconsin deposits_________ 40 lowan substage__ _ _____________________________ 81 Tills found in borings ___________________ 40 Areal distribution. ______-___-__-_-_--_-__-. 81 Boulders____ _ _-____-_______-_-_-_----__ 40 Correlation _______________________________ 83 Outwash_____________________________ 40 Till. _______-.___-_____-_-___ _ ______ _ . 84 Summary of pre-Wisconsin glacial deposits.________ 41 Boulders. _________________________________ 85 in IV CONTENTS Stratigraphy of the Wisconsin deposits—Continued. Page Stratigraphy of the Wisconsin deposits — Continued. Page lowan substage—Continued. Mankato substage — Continued. Ice-contact stratified deposits ________________ 87 Loess ___ _ _ _ _______ -__- _ _.____ 128 Outwash_________________________________ 88 Soil profile _________ _ _ ___________ 128 Loess. _ ____________________________________ 88 Date of Mankato maximum____________-_ 129 Stone concentrate__-_--_____--____________ 88 Summary of Wisconsin stratigraphy _ _-__.___- 129 Topographic expression..____________________ 89 Recent deposits and related features _____----_____ 129 Break between lowan and Tazewell substages ______ 89 Alluvium. ___--_--___--_----_----_----__-__ 129 Tazewell substage______________________________ 90 Frozen-ground phenomena. __________________ 130 Differentiation from the lowan substage _ ______ 90 Water-table fluctuations. _ ___________________ 130 Northeastern South Dakota._____________ 90 Eolian features. _ -________---___-__-_-___--- 131 Central South Dakota__----___..______ 91 Abrasion __ ___________________________ 131 Sections exposing two drifts._________ 92 Deflation _______ ____ ________________ 131 Alluvial fills in the Missouri River 132 trench_________________________ 94 Physical features of the Illinoian and Wisconsin glaciers. 133 Distribution of end moraines.________ 94 Areal pattern of the drift sheets- _ __-.._______-____ 133 Drift border______--_-_____-_-._____._.___ 94 Differences among the Wisconsin drift sheets... 133 Till and end moraines _______________________ 94 Areal pattern of the Illinoian drift. ___________ 133 Stratified drift____________________________ 95 Altitudes of margins of the Wisconsin drift sheets,..- , 134 Loess ___ ---__-___-_--_-_________________- 96 Inferred thicknesses of the James glacial lobe _ ___ . 135 Break between Tazewell and Gary substages_ ______ 96 Physical conditions during lowan and TazeweU Morphologic evidence.______________________ 96 substages. ___________________________________ 136 Stratigraphic evidence....___________________ 97 Sources of the drift. ____________________________ 136 Correlation with the region outside the Wiscon­ Stone counts------------------------------- 136 sin drift___-_--------_----------_--__--_- 99 Sioux quartzite in the drift __ _______________ 137 Gary substage._-______-_--______-__-_._______-_ 99 Close relation of till to bedrock.. _____________ 138 Correlation. _______________________________ 99 Conclusions from lithology of the drift _ ______ 139 Drift border______________________________ 100 Drainage history of central and eastern South Dakota... 139 Till.__-_----____--__-____--_.---________-_ 100 Missouri River. ___________-_________-_-__-_---- 139 Stratigraphic relation to pre-Cary deposits. _ _ _ _ 100 Existing drainage. ___________'___________-_-. 139 Topographic expression___-_-__-__-_______.__ 104 Rearrangement of drainage by the ice sheet---- 140 Stratified drift__-_-_--.__-____.___._._____ 105 Evidence of former drainage _________________ 140 Loess____--._-___-__--_-________-____._.- 107 Method of diversion __ _____________________ 141 Break between Gary and Mankato substages....... 108 Date of diversion. __________________________ 142 Mankato substage______-_______________________ 109 Possible earlier diversion. _ _ ________________ 143 Correlation. _______________________________ 109 Post-diversion events__---__-_--_---_--_---_- 143 Drift border_______________________. 109 Incised meanders __ ____________________ 143 Position, ______________________________ 109 Valleys west and south of the Missouri River Relation to Gary moraines_-_____________ 110 in the Wisconsin age___-_----__------_ 144 Till.______________._._______.___---_---___ 110 Missouri River trench. ____-___-_._-____- 144 Stratigraphic