Origin of the Minnesota River
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OriginOrigin ofof thethe MinnesotaMinnesota RiverRiver andand ItsIts ResponseResponse toto 10,00010,000 YearsYears ofof HydraulicHydraulic ChangeChange CarrieCarrie E.E. JenningsJennings MinnesotaMinnesota GeologicalGeological SurveySurvey Illustration from K. Gran From Patterson and Wright, 1999 Low relief till plains and ice lobe troughs From Greg Balco Photo by Peter Knight Tru Flight for Windows INSAR Velocities, Ian Joughin, JPL RadarSat Whillans Ice Stream From Pat Colgan Complexity of glacial landscape Western margin Des Moines lobe Tunnels in the Des Moines lobe in Minnesota, Patterson, 1996; Iowa, adapted from Kemmis Glacial Lake Minnesota Sediment Dave Bauer MS in soils Illustration from Jim Miller, MGS Significance Lake Agassiz Lowell et al., 2005 Red River Alexandria Moraine Glacial Lake Agassiz Plain Fargo-Moorhead Model for the formation of iceberg drag marks on lake plain Lake Agassiz plain Wild Rice River Great Bend, ND July 1986 N Lake Agassiz Outlet Hudak and Hajc, 2005 From Hudak and Hajc, 2005 Hudak and Hajc, 2005 Kelley et al., 2005 Kelley et al., 2005 Minnesota, & Upper Mississippi Valley Confluence Hajc and Hudak, 2005 •Valley Terrace 1 66 ft of fill in St. Paul, downstream from confluence of Minnesota & Mississippi •Organic sediment near 66 ft = 7,740 ± 60 B.P. •Organic sediment at 32 ft = 5,360 ± 70 B.P. •Organic sediment at 12-14 ft underlying historic fill = 1,910 ± 70 B.P. •Sedimentation timing and rates match alluvial fan sedimentation documented upstream in the MN River Valley St. Croix, Minnesota, & Upper Mississippi Valleys Sequence of Events, Hudak and Hajc, 2005 •Mississippi Valley’s north Minneapolis gap opened >10.7K BP •L. Agassiz catastrophically discharged thru southern outlet as River Warren at 10.7K BP (Fisher, 2001) •MN Valley VT2 LfSA aggraded between ~10.7K and 9.3K(?) BP •St. Croix Valley catastrophically carved 10.1-9.4K BP •Downstream Mississippi/St. Croix “red” beds deposited 9.9-9.7K BP •MN Valley VT2 LfSA abandoned <9.3K BP; down-cutting occurs •Lake St. Croix initial aggradation begins ~9.4-8.3K BP •Aggradation of MN Valley Fans over VT2 LfSA begins ~8.8-7.8K BP •Aggradation of MN/MS Valley Terrace (VT) 1 LfSA begins ~7.8K BP Dave Craigmile Dave Craigmile BEAUFORD WATERSHED PARENT MATERIALS Kasota Ponds Seven Mile Creek Watershed Nicollet County, Minnesota C N D 29 89 1011 St. Peter "!5 Research Fields 17 16 15 Traverse Twp. Osh awa Twp. Minorshed 062 # 21 22 23 3 1 13 99 Oak Leaf Lake "! D %g 25 30 29 28 27C 26 25 le e t k it a L L CD 46 r ve 36 31 32 33$ 35 i Legend Granby Twp. Site 1 # 36 9 6 R Minorshed 066 1 S Nicollet 99 $ e S a v U t Seven Mile Creek %g Site 2 e n Minorshed 063 o ud M s $ Water Quality M i 2 e 1 6 5 4 l 2 e k 17 e n Monitoring Site a "! C k L r ee in Belgrade Twp. Major Roads 13 M 8 Nicollet Twp. 5 "! Public Open Ditch 11 12 D $ 8C 9 10 11 Public Ditch Tile Site 3 Seven Mile Creek 17 16 15 County Park CD 24 City Seven Mile Creek Watershed 2024Miles Redtop Farms Research Fields BNC Water Board_2000 Wetlands K. Keuhner Preliminary data, D.Blumentritt .