Bedrock Geology of Dodge County, Wisconsin (Wisconsin Geological

Bedrock geology of Dodge County, Wisconsin

MAP 508–SUPPLEMENT • 2021 Esther K. Stewart

the land surface. The identification and DODGE COUNTY Introduction mapping of subtle folds in the Paleozoic he accompanying map is an units may also help predict local changes interpretation of the distribution in the physical properties of the bedrock; Tof bedrock units that are present for example, changes in hydraulic conduc- beneath unconsolidated sediments in tivity associated with vertical fracturing Dodge County, Wisconsin. The unconsol- near fold axes (E.D. Stewart and others, idated sediments were mostly deposited in press). by modern and glacial processes during Bedrock units include Proterozoic quartz- the Quaternary Period and are generally ite, schist, banded iron formation (XYb, 20–60 feet (ft) thick, though locally they XYi, Yw), and lesser mafic intrusive rocks range from absent (where bedrock crops and pegmatites (Ypm) nonconformably out) to more than 200 ft thick in preglacial overlain by Paleozoic siliciclastic and bedrock valleys. Bedrock unit contacts carbonate rocks. Precambrian strata are drawn on the buried bedrock surface, (Waterloo Quartzite) were deposited on which is shown in elevation contours on the southeastern margin of Laurentia after the base for this map. This map builds on about 1,630 Ma (mega-annum, or Ma). It recent mapping in Fond du Lac and Sauk is possible that an older unconformable Counties (Batten, 2018; E.D. Stewart and sedimentary succession beneath the others, 2018; E.D. Stewart and E.K. Stewart, Waterloo Quartzite was deposited after 2020), refines the subdivision of the about 1,714 Ma, similar to the Precambrian Precambrian Baraboo interval metased- succession in the Baraboo Hills 50 miles iments (map units XYb, Yw, and XYi; see to the west (E.D. Stewart and others, 2018; also Dott, 1983; E.K. Stewart and others, E.K. Stewart and others, in press). Regional 2016), identifies several low-amplitude events that controlled deformation of folds in the Paleozoic units, and presents these rocks are unresolved (E.K. Stewart new evidence for episodic Paleozoic and others, in press). Baraboo interval reactivation of Precambrian structures. strata show evidence for metamorphism A refinement of the bedrock elevation associated with emplacement of the contours and the areas underlain by dolo- Wolf River batholith at approximately stone bedrock may facilitate identification 1,470 Ma (Medaris and others, 2019), and of those areas that are most susceptible indirect evidence for folding during the to groundwater contamination from the Mazatzal event at approximately 1,630 application of nutrients and pesticides on

Wisconsin Geological and Natural History Survey University of Wisconsin–Madison Division of Extension 3817 Mineral Point Road • Madison, Wisconsin 53705 608.262.1705 • WisconsinGeologicalSurvey.org Kenneth R. Bradbury, Director and State Geologist

An EEO/AA employer, University of Wisconsin-Madison Division of Extension provides equal opportunities in employment and programming, including Title VI, Title IX, the Americans with Disabilities Act (ADA), and Section 504 of the Rehabilitation Act requirements. WISCONSIN GEOLOGICAL AND NATURAL HISTORY SURVEY • 2 toward basinto theeast. the Michigan Paleozoic unitsdipgently 3–5degrees dome was andthe elevated to thenorth tion ofthePaleozoic units. The Wisconsin thedeposi- exposed during subaerially highthat was a structural periodically The maparea overlies the Wisconsin arch, andothers(2019). (2010), andMcLaughlin Choi andothers(1999), Witzke andothers units (Opc, Oa,Os, Om,Su)isbasedon subdivision oftheOrdovician and Silurian based onRunkelandothers(2007). The are of theCambrian-Ordovician boundary Furongian; _e,_tc_t)andtheposition and Late Cambrian units(Epoch3and subdivision oftheCambrian into Middle (2012) aswell asregional studies. The visions are from Gradstein andothers and others, 2019).Chronologic subdi- Runkel andothers, 1998,2007;McLaughlin and others, 1993;Choiandothers, 1999; years ago(for example, Sloss, 1963;Smith a broad, seasome510–430million epeiric as nearshore through offshore depositsin sandstones anddolomites were deposited The overlying Cambrian through Silurian the western limbofthe Waterloo syncline. is exposed inlow-lying outcrops along 2005). Here, the Waterloo (Yw) quartzite County Dodge (Bucholzandothers,ern insouthwest and maficdikes at aquarry 2018) andanexposure ofpegmatites and others, 2016;E.D. andothers, Stewart aeromagnetic Stewart anomalydata (E.K. The evidence for theseevents isfrom for example, Holmandothers, 2020). (about1,100Ma; the Midcontinent Rift maficintrusions maySome be related to others, andothers, 2015;Medaris 2019). 2005; Holmandothers, 2007;Bickford and province Bucholzandothers, (1,400Ma; belt oftheEastern Granite Rhyolite be related to theGreen Islandplutonic with the Wolf Riverbatholith whichmay associated maficintrusions are associated chronologic data suggestpegmatites and age. andgeo Geochemical uncertain (Ypm) of by maficdikesandpegmatites iron formation (XYb, XYi, Yw) are intruded others, 2000). The schist, and quartzite, (Holmandothers,Ma and 1998;Romano - - T Bedrock surface unit that dolostone, flankstheSilurian and Group Maquoketa (Om) isaslope-forming stone. To thewest, shaleoftheOrdovician County that are by dolo underlain Silurian Dodge andnorth-central northeastern face elevations are highestinareas of County. andground-sur Bedrock-surface dolostone (Su)ispresent ineastern Dodge systems. Silurian The ledge-forming that are by dissected preglacial drainage tible to erosion andtend to form slopes units (Om, Oa,_t,_tc)are more suscep contrast, sandstone thesofter andshale tend to capelevated ledgesorplateaus. In Opc) are relatively resistant to erosion and The Paleozoic dolostone units(Su, Os, topographic highwas at thelandsurface. theCambrian Period, during (Yw); this Precambrianburied topographic high side ofthe Waterloo synclineisamostly resistant to erosion. Today, thewestern Precambrian (XYb, quartzite Yw) ismost phy ofthebedrock andlandsurfaces. The bedrock unitsis reflected inthe topogra- resistance to weathering anderosion of Period.the Quaternary The variable sediments of glacialandmodern during developed beforesurface thedeposition ofthetopographyMost onthebedrock sandstone, shale, andquartzite. elevation contours inareas by underlain more looselyfollow thetrend ofsurface 2021).Bedrock elevationStewart, contours by dolostone includeabedrock core (E.K. data suggestsomedrumlinsunderlain units, includingdrumlinfieldswhere WCR in areas by underlain dolostone bedrock topographicthe trend contours ofsurface contours were interpreted to closelyfollow bedrock-surface-elevation observation, to Onthebasisofthis bedrock <50ft). byunderlain shallow dolostone (depth topography surface ent-day inplaces topography closelymimicsthepres- contoured intervals. at 20-ft The bedrock elevation was hand bedrock surface topography.vation oflandsurface The ofAgriculture,Department and obser soilsdata from theU.S. (WCRs), reports information from 3,213well construction preted from depth-to-bedrock bedrockmostly buried was inter ofthe he topographic surface - - - - - subunits are herein elevated from member andIndiana. in Illinois The Maquoketa’s group to more closelyfollow itsusage herein elevated from aformation to a Escarpment. Niagara The is Maquoketa asthe morphology in thelandsurface isdiscontinuouslythis contact expressed units, especiallyto theeastwhere deep trols themappedextent ofthebedrock con- these drainage systems partially with theancestral River. Rock by Incision flowed southinto Jefferson County tojoin and southeastern Columbia Counties. It sandstone (_t,_tcOa)inwestern Dodge less-resistant Cambrian to Ordovician ancestral CrawfishRiver developed over County.River insoutheastern Dodge The Sinissippi Lake, Rock andthemodern occupied by Horicon Marsh, partially Escarpmentandistodaythe Niagara ancestral River that Rock paralleled toward thesouth-southeast-trending eastern branch River, oftheRock orwest flowed eithereast towards theancestral GroupMaquoketa (Om). These tributaries dolostoneSilurian (Su)andshaleofthe the ancestral Riverincisedthe Rock east-trending preglacial to tributaries County,eastern Dodge several east-south- (seefig.In incised thebedrock 1). surface Two mainpreglacial drainage systems Tunnel Groups City (_t,_tc). stone ofthe Cambrian Trempealeau and Chien Group (Opc) sand - andunderlying dolostone oftheOrdovician Prairie du west oftheSinnipee Group, exposing westerndrainages County Dodge dissect the SinnipeeGroup to thewest. Preglacial of theOrdovician Ancell Group (Oa) abut sandstone andshale The slope-forming elevation County. innorthwestern Dodge Ordovician ledgehasthehighestsurface toDue theregional eastward dip, this second broad, relatively elevated ledge. Ordovician SinnipeeGroup (Os) forms a central County, Dodge dolostone ofthe Neda Formation (mudstone to oolite). In shaly dolomite andgrainstone), andthe Formation (dolomiticshaleandlesser Formation (shalydolostone), theBrainard Formation (shale),theFort Atkinson includes (inascending order) theScales to formation rank. The Group Maquoketa 3 • BEDROCK GEOLOGY OF DODGE COUNTY, WISCONSIN 52.5 663 700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 Miles 0 Bedrock elevation, Bedrock sea level above in feet

r e iv k R west-central Dodge County, extending for extendingfor Dodge County, west-central of inclination The 17 miles. approximately as much reaching limbs is subtle, the fold for less but it is probably as 2 degrees, length. fold’s most of the is coincident Dam anticline Beaver The aeromagnetic positive with a curvilinear, in offset slight anomaly and an abrupt, collected A drill data. core the gravity name: axis (drill core along the fold WID: 14001388) recovered WGNHS Slinger; (XYi) overlain formation iron Precambrian Mound Elk of the Cambrian sandstone by contact erosive a sharp, (_e) across Group sea 490 ft above elevated a relatively at angular (>5 centimeters), Large level. incorporated are formation clasts of iron of the Cambrian sandstone lowest the into Prairie Ordovician The Elk Mound Group. and the is absent (Opc) du Chien Group (Oa) Group Ancell Ordovician overlying of contact with sandstone into comes of the Formation Jordan the Cambrian - an uncon (_t) across Group Trempealeau evidence shows core The surface.formable density fracture and small greater for ral Roc cest An Sinissippi Lake Sinissippi Lake - Marsh Marsh Horicon Horicon

a cestr l Cra An w s h River Beaver Dam anticline Beaver is a gentle, Dam anticline Beaver The with anticline east-southeast-plunging a maximum amplitude of approximately is sinuous across trace anticlinal The 75 ft. Paleozoic on the order offset units are Paleozoic The may that small folds by of feet of tens Structures faults. be underlain or cut by correlation the through recognized are well from units identified of Paleozoic and core, construction reports, cuttings, - A series of low-ampli logs. geophysical similar to and synclines tude anticlines in the lead-zinc district those recognized example, (for Wisconsin of southwestern on apparent 1959) are Heyl and others, the structure-contour the on map drawn 2). see fig. (Os; base of the Sinnipee Group struc Descriptions representative of two tures are provided below. below. provided are tures iron formation (E.K. Stewart formation iron and others, the syncline, Waterloo the 2016). Beyond surface Precambrian is poorly constrained wells. distributed unevenly a few by Fox Lake Fox Fox Lake Fox Lake Lake Dam Dam Beaver Beaver

Elevation of Elevation any previously unrecognized unrecognized previously any units are the Paleozoic in folds on the and named identified

the buried bedrock the buried bedrock above surface, in feet Modern sea level. in shown are lakes blue and labeled. approximate The of ancestral locations are rivers preglacial the dashed by shown with lines, yellow indicating arrows the downstream direction. map. Fold geometry with linear aligns Fold map. previously anomalies that aeromagnetic as Precambrian had been interpreted E.K. 2 and 3; and faults (see figs. axes fold 2016). Stewart and others, Figure 1. Figure Precambrian quartzite, and iron schist, Precambrian The by deformed are Yw) XYi, (XYb, formation by be offset and may kilometer-scale folds faults (E.K. Stewartregional-scale and oth- Ypm) (Yw, rocks 2016). Precambrian ers, syncline, Waterloo in the exposed only are kilometer-scale syncline an east-plunging, ellipti- An Dodge County. in southwestern canoe-shapedcal, anom- aeromagnetic aly in northern is likely Dodge County quartzite similarly folded caused by and Structure preglacial valleys cut down into shale of shale into cut down valleys preglacial the removing (Om), the Maquoketa Group (Su). Silurian dolostone overlying M 4 600 55 WISCONSIN GEOLOGICAL AND NATURAL HISTORY SURVEY • Figure 2. County. Geophysical logsandgeologic ofFondto thecity duLacinFond duLac Columbia County) andto thenortheast toextends thesouthwest (bisecting ing setofaeromagnetic anomaliesthat a strong, broad, linear,- northeast-trend The Waupun anticline iscoincident with probably lessfor mostofthefold’s length. reaching asmuch2degrees, butitis The inclination ofthefold limbsissubtle, forextending approximately 12miles. ous across County, northwestern Dodge 60 ft. The anticlinal trace isdiscontinu- a maximumamplitudeofapproximately anticline with east-northeast-plunging The Waupun anticline isagentle, Waupun anticline heavily mineralized withsulfides. Groupfractures inthebasalElkMound are is prevalent withintheAncell Group and from thefold axis. Fracturing andfaulting faults compared to cores away collected geophysical logs, anddrillcore. geologic reports, logs,construction the SinnipeeGroup asrecorded inwell hand from theelevation ofthebase (Os). contours Structure were drawn by base oftheOrdovician Sinnipee Group indicates ofplunge direction arrow (where shown)Syncline—Solid of WaterlooQuartzite anddipofbedding Strike indicates ofplunge direction arrow (where shown)Anticline—Solid includes bothoutcrops rock andburied of Extent Waterloo Quartzite; ofOrdovicianExtent SinnipeeGroup Contour is25feet. interval dotted beyond ofSinnipee. extent Dashed where control well-data islimited; base ofOrdovician Sinnipee Group— Structure contours drawn on Sinnipee Group Well that baseOrdovician intersects Structure-contour mapofthe Structure-contour ! ! ! ! ! ! ! ! ! ! ! 0 ! of overlying Cambrian to Ordovician units. order ofmagnitude larger thantheoffset an isabout300ft, the Precambrian surface A–A(cross'). section offsetThe of observed with thelower Trempealeau Group (_t) the Ancell Group (Oa) comes into contact Chien Group (Opc) islocallyabsent and indicateInstitution that thePrairie du eral deepwells at the Waupun Correctional logs generated from thecuttingsofsev 950 CountyDodge are consistent withregional mation are inconclusive. in Observations available data constraining suchdefor 1959); however, County, inDodge the are likelyalsodeformed (Heylandothers, Group (Om) dolostone andSilurian (Su) (Oa). The overlying Ordovician Maquoketa _t) through theOrdovician Ancell Group of theCambrian sandstones (_e,_tc ical logsdemonstrate thedeformation logs, well cuttings, core, drill andgeophys- County, Dodge In ofdrillers’ observations Interpretation ! ! ! ! ! ! ! ! 900 !

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! 400 ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! - ! ! ! ! ! ! ! ! ! ! ! - ! ! ! 350 450 ! ! 5 • BEDROCK GEOLOGY OF DODGE COUNTY, WISCONSIN Structure contours drawn on drawn Structure contours –36 2,083 196 251 293 330 364 398 431 462 492 521 552 586 625 669 725 793 885 1,043 nT Nanotela the base of the Ordovician Sinnipee the base of the Ordovician reduced- on overlain 2) fig. (from Group anomaly to-pole (RTP) aeromagnetic anomalies reflect Aeromagnetic map. in the upper crust; contrast magnetic to responds this data Wisconsin, in basement in the Precambrian variations rocks Paleozoic because the overlying mostly and Quaternary are sediments Paleozoic transparent. magnetically with linear closely align axes fold with anomalies (compare aeromagnetic 2), supportingfig. the interpretation structures were Precambrian that during the Paleozoic. reactivated (2002) and See Daniels and Snyder Stewart and others (2018) for E.D. a description of the aeromagnetic dataset. Figure 3. Figure

more proximal setting over the Wisconsin Wisconsin the setting over proximal more City Tunnel Cambrian overlying The arch. (_t) Group Trempealeau (_tc) and Group thicknesses, their maintain indicating did not deformation Cambrian potential deposi- the persist much longer beyond tion of the Elk Mound Group. importantAn period of deformation the end of Early Ordovician by developed pronounced in a more resulting time, and oth- (Heyl arch Wisconsin uplift of the Middle Early to This Ordovician 1959). ers, likely caused the localized deformation Chien du uplift of the Prairie and erosion of the the deposition before (Opc) Group Mapping in (Oa). Group Ancell overlying with Minnesotasoutheastern is consistent these observations and further documents the changes in thicknesses within the interpreted are that du Chien Group Prairie syndepositional tectonism for as evidence 2015, 2018). Closer and others, (Steenberg Hills in the Baraboo Dodge County to

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graphic high by Middle Cambrian time. Middle high by time. Cambrian graphic fine-grainedThe fraction charac is that (_ee) Formation of the Eau Claire teristic is minimal to Wisconsin in elsewhere in all but perhaps Dodge eastern absent of the winnowing likely due to County, higher-energy, in a slightly grains the finer - devel earlyAn period of uplift have may oped during the Middle shortly Cambrian, or during of the the deposition before ) of the (_em Mount Formation Simon for evidence The (_e). Elk Mound Group this uplift the observation is mostly from formation angular clasts of iron of large, the base of the Elk into incorporated WGNHS Slinger drill in the Mound Group Dam along the axis of the Beaver core and angularity size of these The anticline. they indicate clasts soft, poorly resistant the land surface at exposed shortlywere the basal into incorporation their before overall The detritus. Elk Mound Group of the Elk Mound Group size grain coarse Wisconsin suggests the in Dodge County as a topo subtly expressed was arch 700 650

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900 950 0 –36 2,083 196 885 669 725 793 625 552 586 492 521 398 431 462 330 364 251 293 1,043 ture contours drawn on the base of the on the base drawn contours ture with to align tend 2) (fig. Sinnipee Group likely reflect that anomalies geophysical structures the underlying in Precambrian E.K. 2007; Holm and others, 3; (fig. rocks coincidence The 2016). Stewart and others, faults with Precambrian folds of Paleozoic is observed some 40 Hills, in the Baraboo Stewart (E.D. of Dodge County miles west and E.K. Stewart, 2020). In Dodge County, surfacePrecambrian of the offset the large overlying of the the offset to relative units observed along the axes Paleozoic anticlines Waupun Dam and of the Beaver defor Precambrian to be attributed may which supports mation, the interpretation reactivated older structures were that during the Paleozoic. The fold axes interpreted from the struc from interpreted axes fold The nT

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900 950 WISCONSIN GEOLOGICAL AND NATURAL HISTORY SURVEY • 6 T Acknowledgments A–A cross' andB–B'). sections conclusively thanfor units(see underlying subtle folding oftheseunits, thoughless overlying dolostone Silurian (Su)indicates Ordovician Group Maquoketa (Om) and mappingofthebase Subsurface fracture development andmineralization. ing SinnipeeGroup (Os) andlocalized resulting inthefolding oftheoverly deposition oftheAncell Group (Oa), Subtle deformation continued the after 2020). Stewart, andE.K. Stewart du ChienGroup are gently folded (E.D. County,of Sauk outcrops ofthePrairie and examine rock outcrops. bedrock core drill to extract their property to thelandowners whoallowed access to ofthemap.the quality Finally, thankyou provided review comments that improved Julia Steenberg, andJohnCraddock tural interpretation ofthemap. BillBatten, me improve thestratigraphic andstruc Tony Runkel, andPat helped McLaughlin discussions withBillBatten, Stewart, Eric rig. runningthedrill Insightful expertise thanks to BillBatten for hiscare and Elizabeth Koozmin edited themap. Special transformation. theRTP and performed compiled aeromagneticSurvey) data ical logs. Anderson (U.S. Eric Geological core ofdrill the collection andgeophys- cessing samples. Pete Chasecoordinated core drill assisted with collecting andpro Drae Rogers, Alex Walker, andJay Zambito Lamb, Pat Neuman, Mason McLaughlin, Guenther, Matt Hurth, LisaHaas, Mike DeBruyne, Ana Genthe,Jackie Greg Amber Boudreau, Sarah Bremmer, contributions ofmany collaborators. benefitedhis project from the - - - References Craddock, J.P.Craddock, andvan derPluijm, B.A., Clayton, L.,andAttig, J.W., 1990,Geology Choi, Y.S., Simo, J.A., andSaylor, B.Z., Bucholz, T.W., Falster, A.U., andSimmons, Bickford, M.E., Van Schmus, W.R., Karlstrom, Batten, W.G., 2018,Bedrock geologymap North America: Geology, America: North v. 17,416–419. the cratonic carbonate cover ofeastern 1989, Late Paleozoic deformation of pubs/000317/. scale 1:100,000,https://wgnhs.wisc.edu/ Information Circular 67,68p., 2plates, Survey Geological andNatural History County, Sauk Wisconsin: Wisconsinof p. 275–289. SpecialPublicationGeology 63, formodels: SEPM Sedimentary Society Application to reservoirs, outcrops, and in carbonate sequence stratigraphy: P.M., andSimo, J.A., eds., Advances Formations, Wisconsin, in Harris, Upper Ordovician Decorah andGalena tomidcontinent sea, Middle epeiric ramp,mixed carbonate-siliciclastic stratigraphic interpretation ofa 1999, Sedimentologic andsequence Geology, v. 65,p. 8–9. onLakeSuperior Institute abstracts: Proceedings, Part 1—program and Ontario,Nipigon, May 24–28,2005, Geology,Superior 51stannualmeeting, Hollings, P., eds., onLake Institute Waterloo, WI [abs.], inEaston, M.,and zones, Materials Quarry, Michels and spatially associated metasomatized W.B., ofpegmatites 2005,Mineralogy p. 286–312. Precambrian Research, v. 265, andNdisotopic compositions:and Hf ages, zircon saturation temperatures, wide agedistributions, newSIMSU-Pb magmatism: Asynthesis ofcontinent- 2015, Mesoproterozoic-trans-Laurentian Mueller,K.E., P.A., andKamenov, G.D., pubs/000963/. scale 1:100,000,https://wgnhs.wisc.edu/ M505,2plates, Map Survey History Wisconsin Geological andNatural of Fond duLacCounty, Wisconsin: Heyl, A.V., Jr., Agnew, A.F., Lyons, E.J., Gradstein, F.M., Ogg, J.G., M.D., Schmitz, Haroldson, E.L., Beard, B.L., Satkoski, R.H.,Jr.,Dott, 1983, The Proterozoic red Daniels, D.A., andSnyder, S.L.,2002, Holm, D., Medaris, L.G.,Jr., McDannell, Holm, D.K., Anderson, R.,Boerboom, Holm, D., Schneider, D., andCoath, C.D., Professional Paper 309,310p., 24plates U.S. lead district: Geological Survey of theupperMississippi Valley zinc- and Behre, C.H.,Jr., 1959, The geology scale 2012:Oxford, U.K., Elsevier, 1,176p. and Ogg, G.M.,2012, The geologic time 1583–1595. Bulletin,v. ofAmerica Society 130,p. Pb isotope Geological perspective: with Mississippi Valley-type fluids:A remobilization2018, Gold associated A.M., Brown, P.E., andJohnson,C.M., 160,p.Memoir 129–141. region: ofAmerica Geological Society Proterozoic geologyoftheGreat Lakes collision? inMedaris, L.G.,Jr., ed., Early United States: Resolved by plate enigma inthenorth-central quartzite of02-493/. https://pubs.usgs.gov/of/2002/ 2002–493, Open-FileSurvey Report ofdata:distribution U.S. Geological maps anddata; aweb site for Wisconsin aeromagnetic andgravity Research, v. 339,106687. region:Lake Superior Precambrian Proterozoic provinces inthesouthern overprinting, and stabilization of B.S., andJicha,B.R., 2020,Growth, K.T., Schneider, D.A., Singer, K., Schulz, Precambrian Research, v. 157,p. 71–79. aeromagnetic-geologic compilation: central United States basedonanew ofthenorth- boundaries accretionary Reinterpretation ofPaleoproterozoic and K.J., Van Schmus, W.R., 2007, M., Miller, J., Schneider, D.A., Schulz, T.J., Cannon, W.F., Chandler, V., Jirsa, 26, p. 907–910. final assemblyofLaurentia:Geology, v. extent offoreland deformation during region:Lake Superior for Implications Proterozoic inthesouthern quartzites 1998, Age anddeformation ofEarly 7 • BEDROCK GEOLOGY OF DODGE COUNTY, WISCONSIN fr202101/. K., mapping of bedrock 2020, New the geologic improves Dodge County understanding and for framework managing southeast Wisconsin’s Madison, [abs.]: resources groundwater Association, Resources Water American Meeting. Annual Chapter Wisconsin Revised provenance, in press, E.D., and depositional environment, the maximum depositional age for (