Physical Sciences and Mathematics Commons^™

Subsurface Geophysical Investigations Of Oneida Lake Ny: Insights Into Ice Sheet Processes And Deglaciation At Termination I, Nicholas John Zaremba

Dissertations - ALL

Reconstructing the retreat of the Laurentide Ice Sheet (LIS) provides insight into understanding end-Pleistocene climate, a critical set of boundary conditions prior to the onset of Holocene climates that were optimal for human dispersal and societal growth. Constraining ice sheet dynamics, glacier retreat rates, and the timing of still-stands and readvances requires identifying glacial landforms such as moraines, drumlins, and mega-scale glacial lineations (MSGLs). Drumlins and MSGLs indicate ice sheet flow directions and provide the location of paleo-ice streams, which were accelerated and localized pathways for ice discharge. Ice streams control ice sheet mass balance; therefore, identifying the location of …

Chronology Of Advance And Recession Dynamics Of The Southern Green Bay Lobe Of The Laurentide Ice Sheet, South-Central Wisconsin, Usa, Eric C. Carson, John W. Attig, J. Elmo Rawling Iii, Paul R. Hanson, Stefanie E. Dodge

School of Natural Resources: Faculty Publications

We used a combination of accelerator mass spectrometry (AMS) radiocarbon dating, optically stimulated luminescence (OSL) age estimates, and stratigraphic data from cores collected along the southern margin of the Green Bay Lobe (GBL) of the Laurentide Ice Sheet to provide new information on the timing and dynamics of the end of advance of the GBL and the dynamics of the ice sheet while very near its maximum position. Coring at multiple sites along the margin of the GBL indicate that ice had reached a stable position near its maximum extent by 24.7 ka; that ice advanced several kilometers to the …

Geochemistry And Mineralogy Of Late Quaternary Loess In The Upper Mississippi River Valley, Usa: Provenance And Correlation With Laurentide Ice Sheet History, Daniel R. Muhs, E. Arthur Bettis Iii, Gary L. Skipp

United States Geological Survey: Staff Publications

The midcontinent of North America contains some of the thickest and most extensive last-glacial loess deposits in the world, known as Peoria Loess. Peoria Loess of the upper Mississippi River valley region is thought to have had temporally varying glaciogenic sources resulting from inputs of sediment to the Mississippi River from different lobes of the Laurentide Ice Sheet. Here, we explore a new method of determining loess provenance using K/Rb and K/Ba values (in K-feldspars and micas) in loess from a number of different regions in North America. Results indicate that K/Rb and K/Ba values can distinguish loess originating from …

Oxygen-Isotope Variations In Post-Glacial Lake Ontario, Ryan Hladyniuk, Fred J. Longstaffe

Earth Sciences Publications

The role of glacial meltwater input to the Atlantic Ocean in triggering the Younger Dryas (YD) cooling event has been the subject of controversy in recent literature. Lake Ontario is ideally situated to test for possible meltwater passage from upstream glacial lakes and the Laurentide Ice Sheet (LIS) to the Atlantic Ocean via the lower Great Lakes. Here, we use the oxygen-isotope compositions of ostracode valves and clam shells from three Lake Ontario sediment cores to identify glacial meltwater contributions to ancient Lake Ontario since the retreat of the LIS (~16,500 cal [13,300 ¹⁴C] BP). Differences in mineralogy …

Stratigraphy And Extent Of The Pearl-Ashmore Aquifer, Mchenry County, Il, Usa, Drew C. Carlock, David H. Malone, Jason F. Thomason, Eric Wade Peterson

Eric Wade Peterson

Ice-Movement History And Kimberlite Indicator Mineral Dispersal Study, Pelly Bay, Lower Boothia Peninsula, And Wager Plateau Areas, Nunavut, Canada, Carl Ozyer

Electronic Thesis and Dissertation Repository

This study reconstructs the ice flow history of the eastern portion of the Keewatin sector of the Laurentide Ice Sheet by integrating field work, remote imagery, and work by others. The study reveals at least seven ice flow phases during the Wisconsinan, including ice streams. A model was developed using inverse distance weighed (IDW) interpolation with GIS to identify and isolate potential kimberlite bedrock sources in kimberlite indicator mineral-rich areas in the Pelly Bay area, Nunavut. Kimberlite indicator mineral (KIM) data were normalized by “peer size” to better understand how KIM grains from three kimberlite sources are distributed within three …

Sger: Is Bolling Warming Recorded By The Southeastern Margin Of The Laurentide Ice Sheet?, Harold W. Borns Jr., Brenda Hall

University of Maine Office of Research Administration: Grant Reports

This award, under the auspices of the Small Grants for Exploratory Research (SGER) program, uses funds to increase the chronologic control for the southeastern margin of the Laurentide Ice Sheet (LIS). Ultimately, the researchers want to explore whether they are able to document the response of the ice sheet to major shifts in atmospheric temperature and assess the ability of the ice sheet to produce large volumes of meltwater.

The effect of prominent climate events, such as the Bolling warming (13,000 radiocarbon years before present), on the dynamics of the Laurentide Ice Sheet (LIS) remains unknown and yet has important …

Collaborative Research: Did The Laurentine Ice Sheet Control Abrupt Climate Change?, Terence J. Hughes, James L. Fastook, David Bromwich, E. Richard Toracinta

University of Maine Office of Research Administration: Grant Reports

This is a collaborative project with the University of Maine and Ohio State University. The Principal Investigators will model the late glacial Laurentide Ice Sheet from near steady-state equilibrium at - 25,000 BP (years before present), through reversible stadial/interstadial transitions associated with Laurentide iceberg outbursts (Heinrich events 2 and 1), and across the threshold of irreversible Laurentide collapse after the last iceberg outburst at - 1 1,000 BP (Heinrich event 0). The goals are to determine if ice-sheet changes could have triggered climate changes by abrupt ice sheet change and to investigate the structure of these changes. The Principal Investigators …