Late Quaternary Histories of Lakes Huron and Michigan

Late Quaternary Histories of Lakes Huron and Michigan PDF Author: Rebecca Amy Macdonald
Publisher:
ISBN:
Category :
Languages : en
Pages : 600

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Book Description
Late Quaternary histories are investigated here for sediment cores from Lakes Huron and Michigan, using the oxygen- and carbon-isotope compositions of biogenic carbonates and the oxygen- and hydrogen-isotope compositions of porewater. Age models for these cores are based on sedimentological information, and where possible, radiocarbon and pollen dates. The Michigan Basin cores provide a thick record of the late Pleistocene, whereas the Huron Basin cores primarily record Holocene deposition. Taken together, the histories recorded in biogenic carbonates from these sediments provide a clear account of lakewater isotopic changes - and their significance - over much of the history of the Great Lakes Basin. Biogenic carbonates, and ostracodes in particular, serve as excellent recorders of lakewater!18O values. Modern specimens from Lake Huron have been used to assess non-equilibrium oxygen- and carbon-isotope fractionation effects during shell formation within this setting. This information provides improved ability to calculate the oxygenisotopic compositions of paleolakewater using fossil biogenic carbonates from the cores. The fossil shell compositions indicate intervals characterized by low!18O meltwater originating from the retreating Laurentide Ice Sheet and/or associated proglacial lakes, and periods dominated by higher!18O water that are more reflective of regional precipitation, runoff and climatic conditions. Differences in the oxygen- and carbonisotope compositions of deep- versus shallower-water ostracode species in the Michigan Basin cores suggest isotopic stratification of its lakewater during the late Pleistocene. Results for previously unstudied parts of the Huron Basin suggest that sub-basins acquired different oxygen-isotope compositions during periods of very low lake levels, reflecting different water sources and/or different conditions at such times. Early Holocene influxes of glacial meltwater into the Huron Basin, and to a lesser extent the Michigan Basin, correlate with major global climate perturbations that were likely triggered by release of large volumes of glacial meltwater into the Arctic and/or North Atlantic Oceans. Porewater did not preserve original lakewater!18O and!D values. These compositions are largely controlled by downward diffusion of modern lakewater.

Late Quaternary Histories of Lakes Huron and Michigan

Late Quaternary Histories of Lakes Huron and Michigan PDF Author: Rebecca Amy Macdonald
Publisher:
ISBN:
Category :
Languages : en
Pages : 600

Get Book Here

Book Description
Late Quaternary histories are investigated here for sediment cores from Lakes Huron and Michigan, using the oxygen- and carbon-isotope compositions of biogenic carbonates and the oxygen- and hydrogen-isotope compositions of porewater. Age models for these cores are based on sedimentological information, and where possible, radiocarbon and pollen dates. The Michigan Basin cores provide a thick record of the late Pleistocene, whereas the Huron Basin cores primarily record Holocene deposition. Taken together, the histories recorded in biogenic carbonates from these sediments provide a clear account of lakewater isotopic changes - and their significance - over much of the history of the Great Lakes Basin. Biogenic carbonates, and ostracodes in particular, serve as excellent recorders of lakewater!18O values. Modern specimens from Lake Huron have been used to assess non-equilibrium oxygen- and carbon-isotope fractionation effects during shell formation within this setting. This information provides improved ability to calculate the oxygenisotopic compositions of paleolakewater using fossil biogenic carbonates from the cores. The fossil shell compositions indicate intervals characterized by low!18O meltwater originating from the retreating Laurentide Ice Sheet and/or associated proglacial lakes, and periods dominated by higher!18O water that are more reflective of regional precipitation, runoff and climatic conditions. Differences in the oxygen- and carbonisotope compositions of deep- versus shallower-water ostracode species in the Michigan Basin cores suggest isotopic stratification of its lakewater during the late Pleistocene. Results for previously unstudied parts of the Huron Basin suggest that sub-basins acquired different oxygen-isotope compositions during periods of very low lake levels, reflecting different water sources and/or different conditions at such times. Early Holocene influxes of glacial meltwater into the Huron Basin, and to a lesser extent the Michigan Basin, correlate with major global climate perturbations that were likely triggered by release of large volumes of glacial meltwater into the Arctic and/or North Atlantic Oceans. Porewater did not preserve original lakewater!18O and!D values. These compositions are largely controlled by downward diffusion of modern lakewater.

Late Quaternary History of the Lake Michigan Basin

Late Quaternary History of the Lake Michigan Basin PDF Author: Allan Frank Schneider
Publisher: Geological Society of America
ISBN: 0813722519
Category : Science
Languages : en
Pages : 133

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Book Description


Quaternary Glaciations - Extent and Chronology

Quaternary Glaciations - Extent and Chronology PDF Author: J. Ehlers
Publisher: Elsevier
ISBN: 0444534474
Category : Science
Languages : en
Pages : 1128

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Book Description
The book presents an up-to-date, detailed overview of the Quaternary glaciations all over the world, not only with regard to stratigraphy but also with regard to major glacial landforms and the extent of the respective ice sheets. The locations of key sites are included. The information is presented in digital, uniformly prepared maps which can be used in a Geographical Information System (GIS) such as ArcView or ArcGIS. The accompanying text supplies the information on how the data were obtained (geomorphology, geological mapping, air photograph evaluation, satellite imagery), how the features were dated (14C, TL, relative stratigraphy) and how reliable they are supposed to be. All references to the underlying basic publications are included. Where controversial interpretations are possible e.g. in Siberia or Tibet, this is pointed out. As a result, the information on Quaternary glaciations worldwide will be much improved and supplied in a uniform digital format. The information on the glacial limits is compiled in digital form by the coordinators of the project, and is available for download at: http://booksite.elsevier.com/9780444534477/ Completely updated detailed coverage of worldwide Quaternary glaciations Information in digital, uniformly prepared maps which can be used in a GIS such as ArcView or ArcGis Step-by-step guideline how to open and use ArcGis files Possibility to convert the shapefiles into GoogleEarth kmz-files Availability of chronological controls

Late Quaternary Sediments of Lake Michigan (Classic Reprint)

Late Quaternary Sediments of Lake Michigan (Classic Reprint) PDF Author: Jerry T. Wickham
Publisher: Forgotten Books
ISBN: 9780331374384
Category :
Languages : en
Pages : 32

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Book Description
Excerpt from Late Quaternary Sediments of Lake Michigan The maps revealed that the glaciolacustrine Equality Formation is dis continuous in Lake Michigan; however, in an area southwest of Grand Haven, Michigan, it displays a thickening that probably represents an offshore exten sion of the Allendale Delta of the glacial Grand River. The two lower members of the overlying Lake Michigan Formation are thickest in the deepwater basins of Lake Michigan. These lower members are composed of an extremely fine grained red glaciolacustrine clay deposited from suspension. In contrast, the upper three units of the Lake Michigan Formation are thickest in a belt along the eastern side of the lake and consist of gray clay resulting from erosion within the Lake Michigan drainage basin by waves and streams. A large influx of sediments from streams in western Michigan and possible redistribution of shoreline erosion debris by lake currents causes the accumulation of gray clay to be greatest on the eastern side of the lake. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Paleolimnology and the Reconstruction of Ancient Environments

Paleolimnology and the Reconstruction of Ancient Environments PDF Author: Ronald B. Davis
Publisher: Springer Science & Business Media
ISBN: 9400926553
Category : Science
Languages : en
Pages : 255

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Book Description
stable or falling water levels, and permit differen tiation between gradual and sudden transgression The level of Lake Ontario was long assumed to of the shoreline. Vegetational succession reflects have risen at an exponentially decreasing rate shoreline transgression and increasing water solely in response to differential isostatic rebound depth as upland species are replaced by emergent of the St. Lawrence outlet since the Admiralty aquatic marsh species. If transgression continues, Phase (or Early Lake Ontario) 11 500 years B. P. these are in turn replaced by floating and sub (Muller & Prest, 1985). Recent work indicates merged aquatic species, commonly found in water that the Holocene water level history of Lake to 4 m depth in Ontario lakes, below which there Ontario is more complex than the simple rebound is a sharp decline in species richness and biomass model suggests. Sutton et al. (1972) and (Crowder et al. , 1977). This depth varies with Anderson & Lewis (1982, 1985) indicate that physical limnological conditions in each basin. periods of accelerated water level rise followed by Because aquatic pollen and plant macrofossils are temporary stabilization occurred around 5000 to locally deposited, an abundance of emergent 4000 B. P. The accelerated water level rise, called aquatic fossils reflects sedimentation in the littoral the 'Nipissing Flood', was attributed to the cap zone, the part of the basin shallow enough to ture of Upper Great Lakes drainage. support rooted vegetation.

Preceramic Occupations Along the North Shore of Lake Ontario

Preceramic Occupations Along the North Shore of Lake Ontario PDF Author: Arthur C. B. Roberts
Publisher: University of Ottawa Press
ISBN: 177282125X
Category : Social Science
Languages : en
Pages : 250

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Book Description
A preceramic cultural chronology for the north shore of Lake Ontario is synthesized with eastern North American archaeological and paleoenvironmental research. Analysis include projectile point identifications, lithic metric attributes, raw material sources and site characteristics.

Coastline and Dune Evolution along the Great Lakes

Coastline and Dune Evolution along the Great Lakes PDF Author: Timothy G. Fisher
Publisher: Geological Society of America
ISBN: 0813725089
Category : Nature
Languages : en
Pages : 244

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Book Description
"Stemming from research in the three upper Great Lakes basins (Superior, Michigan, and Huron), the volume is organized by geologic time, beginning with the reconstructed drainage for glacial Lake Minong southward across Michigan's Upper Peninsula and ending with the use of remote sensing and geospatial analysis in monitoring Lake Michigan coastal dunes"--

The Fisher Site

The Fisher Site PDF Author: Peter L. Storck
Publisher: U OF M MUSEUM ANTHRO ARCHAEOLOGY
ISBN: 0915703416
Category :
Languages : en
Pages : 328

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Presque Isle Peninsula Beach Erosion, Lake Erie

Presque Isle Peninsula Beach Erosion, Lake Erie PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 268

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Quaternary Coasts of the United States

Quaternary Coasts of the United States PDF Author: Charles H. Fletcher
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 474

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Book Description