00602nas a2200169 4500008004100000245011500041210006900156260005300225300001000278653001200288100001800300700002200318700001300340700001700353700001800370856004400388 2013 eng d00aContrasting Terrains of the Lake Michigan and Saginaw Lobes of the Laurentide Ice Sheet in Southern Michigan;0 aContrasting Terrains of the Lake Michigan and Saginaw Lobes of t aBoulder, ColoradobGeological Society of America a15-3610ageology1 aKehew, A., E.1 aKozlowski, A., L.1 aBird, B.1 aEsch, J., M.1 aGillespie, R. uhttp://dx.doi.org/10.1130/2013.0031(03)02298nas a2200169 4500008004100000245009900041210006900140300001200209490000700221520175800228653001201986100001801998700001802016700001702034700002202051856005502073 2013 eng d00aOn the Origin of Tunnel Valleys of the Saginaw Lobe of the Laurentide Ice Sheet; Michigan, USA0 aOrigin of Tunnel Valleys of the Saginaw Lobe of the Laurentide I a442-4620 v423 a
Tunnel valleys are common throughout the terrain of the Saginaw Lobe of the Laurentide Ice Sheet in southern Michigan. The set of valleys described in this paper is regularly spaced in a radial pattern behind the Kalamazoo Moraine, an ice-marginal position formed during retreat from the Last Glacial Maximum. These valleys are divided into proximal and distal groups lying north and south, respectively, of a major river valley that cross-cuts the tunnel valleys at right angles. Based on a series of rotasonic borings and core analysis, the proximal valleys are shallow, contain minimal sediment fill, and overlie fine-grained diamicton and glaciolacustrine sediment, whereas the distal valleys are deeply incised into the substrate and are partially filled with coarse sediment. The distal valleys terminate within a broad zone of high-relief, hummocky topography representing stagnation and collapse behind the Kalamazoo ice margin. The proximal valleys occur within a more subdued landscape located farther from the ice margin. Although some elements of existing genetic models are consistent with these valleys, none appears to be completely compatible with their stratigraphy and morphology. Initial incision of the valleys could have involved short-lived moderate- to high-discharge flows, followed by deposition during or after the events. The deep incision and thick, coarse sediment in distal valleys in the stagnant marginal zone probably involved supraglacial meltwater draining to the bed as the margin downwasted. Fining-upward eskers inset into the valleys were formed by flows of declining energy in small late-stage conduits.
The surficial terrain of the Saginaw Lobe in southern Michigan is divided into 4 landsystems, numbered sequentially from southwest to northeast, containing related assemblages of sediments and landforms, two of which appear to have a genetic relationship with the bedrock units over which they lie. Landsystem 1 consists of the Sturgis Moraine, a terminal/recessional moraine, and an adjacent drumlin field. The moraine is a high-relief ridge with hummocky topography and ice-walled lake plains at its crest, and thick, coarse outwash fans on its distal margin. The drumlin field extends up-glacier from the Sturgis Moraine across the subcrop of the Mississippian Coldwater Shale to the subcrop of the overlying Marshall Sandstone. The low permeability of the shale may have increased basal pore pressures into a range in which deformation of basal sediment into drumlins occurred. Landsystem 2 overlies the subcrop of the Marshall Sandstone. Stagnation of the lobe behind a discontinuous moraine in this area is indicated by high relief, collapse topography, composed of kames, eskers, and ice-walled lake plains. A system of tunnel valleys terminates and merges in this landsystem with large outwash fans and plains sloping away from the margin. High basal drainage into the sandstone may have facilitated stagnation across a broad area to form this landsystem. Landsystem 3 may have also developed during stagnation of the lobe, but it differs from landsystem 2 by its more subdued relief. It contains a network of evenly spaced, southwest-trending open tunnel valleys that contain discontinuous esker segments. Landsystem 4 consists of till plains and low recessional moraines formed as the Saginaw Lobe retreated downslope into Saginaw Bay of the Lake Huron Basin. Tunnel valleys are absent in this area.
10aglacial geology1 aKehew, A., E.1 aEsch, J., M.1 aKozlowski, A., L.1 aEwald, S., E. uhttp://dx.doi.org/10.1016/j.quaint.2011.07.02100840nas a2200193 4500008004100000245007400041210006900115260005100184300001200235653001200247100001800259700001700277700002200294700001900316700001300335700002000348700001800368856026000386 2009 eng d00aProglacial Megaflooding Along the Margins of the Laurentide Ice Sheet0 aProglacial Megaflooding Along the Margins of the Laurentide Ice aCambridge, EnglandbCambridge University Press a104-12710ageology1 aKehew, A., E.1 aLord, M., L.1 aKozlowski, A., L.1 aFisher, T., G.1 aBurr, M.1 aCarling, P., A.1 aBaker, V., R. uhttps://books.google.com/books?id=fuC04-ZOs9EC&lpg=PA104&ots=3GUJR7O8G-&dq=Proglacial%20Megaflooding%20Along%20the%20Margins%20of%20the%20Laurentide%20Ice%20Sheet&lr&pg=PA104#v=onepage&q=Proglacial%20Megaflooding%20Along%20the%20Margins%20of%20the%20Laure00492nas a2200157 4500008004100000245003800041210003800079260003700117300001200154653001200166100001800178700001700196700002200213700001800235856008100253 2007 eng d00aGlacifluvial Landforms of Erosion0 aGlacifluvial Landforms of Erosion aAmsterdam, NetherlandsbElsevier a818-83110ageology1 aKehew, A., E.1 aLord, M., L.1 aKozlowski, A., L.1 aElias, S., A. uhttps://www.nysm.nysed.gov/staff-publications/glacifluvial-landforms-erosion00490nas a2200157 4500008004100000245005500041210005300096260003300149300001000182653001200192100001800204700002200222700001800244700001500262856005500277 2007 eng d00aTunnel Channels of the Saginaw Lobe, Michigan, USA0 aTunnel Channels of the Saginaw Lobe Michigan USA bGeological Survey of Finland a69-7810ageology1 aKehew, A., E.1 aKozlowski, A., L.1 aJohansson, P.1 aSarala, P. uhttp://arkisto.gtk.fi/sp/sp46/sp46_pages_69_77.pdf