Download or read book Pleistocene Laurentide Ice Sheet Drainage Into the Labrador Sea Sedimentary Facies Depositional Mechanisms Stratigraphy and Significance of Heinrich Events written by and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Canadian Journal of Earth Sciences written by and published by . This book was released on 2016 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Depositional facies of late Pleistocene Heinrich events in the Labrador Sea written by R. Hesse and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CIM Bulletin written by Canadian Institute of Mining and Metallurgy and published by . This book was released on 2001 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quarterly Bulletin of the Canadian Mining Institute written by Canadian Institute of Mining, Metallurgy and Petroleum and published by . This book was released on 2001 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gestational diabetes mellitus and long term maternal outcomes written by Marilza Rudge and published by Frontiers Media SA. This book was released on 2023-02-14 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1998 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Deep sea Record of Rapid Late Pleistocene Paleoclimate Change and Ice sheet Dynamics in Labrador Sea Sediments written by Harunur Rashid and published by . This book was released on 2002 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The presence of H3 between 46° and ~63°N in the Labrador Sea, previously debated, has been proved. Thickness variations for H3 were compiled on an isopach map showing a maximum thickness of 4.8 m near Hudson Strait and thinning to 30 cm in the central Labrador Sea." --
Download or read book Past Glacial Environments written by John Menzies and published by Butterworth-Heinemann. This book was released on 1996 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: This undergraduate textbook provides a current and comprehensive survey of the sediments and forms generated within Pleistocene and pre-Pleistocene glacial environments. Techniques and methods used in the examination of these sediments and forms are extensively reviewed. This is the most comprehensive and wide-ranging book ever prepared on this topic, and will form the basis for future work in the area. In studying past glacial environments, links are made between understanding modern glaciodynamics, ice physics, and the processes of erosion, transport and deposition of glacial sediments and the generation of various glacial landforms. Past Glacial Environments presents physical geography, earth and environmental science students with an extensive review of the latest research on past glacial environments. The text encompasses Pleistocene subglacial, supraglacial and proglacial sediments and environments, pre-Pleistocene global glacial conditions and sediments, as well as past glacioaeolian, glaciolacustrine, and glaciomarine sediments. Subsequent chapters focus on stratigraphy, lithofacies associations, paleosols, glacio-eustasy and isostasy, micromorphology, SEM, drift prospecting and placer mining.
Download or read book CRREL Bibliography written by and published by . This book was released on 1999 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chronology Paleoecology and Stratigraphy of Late Pleistocene Sediments from the Hudson Bay Lowlands Canada written by April Sue Dalton and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Stratigraphic records in the Hudson Bay Lowlands (HBL), Canada, offer rare insight into local paleoenvironments and the Late Pleistocene climate system over North America. Age determinations on sub-till non-glacial materials suggest that the HBL, lying near the centre of the Last Glacial Maximum (LGM) extent of the Laurentide Ice Sheet (LIS), was ice-free for parts of Marine Isotope Stage 3 (MIS 3; 57,000 to 29,000 yr BP), MIS 5 (130,000 to 71,000 yr BP) and MIS 7 (243,000 to 190,000 yr BP). The MIS 3 age assignment is notable since it suggests the possibility of significant retreat of the LIS and a relatively high global sea level, both of which are a contrast to assumptions that North America was moderately glaciated, and that global sea level was relatively low during that time interval. Paleoecological proxies, including pollen and plant macrofossils, suggest that the HBL contained peatland and boreal vegetation during all previous non-glacial intervals, and pollen-based quantitative reconstructions of sites which are hypothesized to be MIS 3 and MIS 5a (~80,000 yr BP) in age suggest that climate during MIS 3 may have had less annual precipitation than during MIS 5a and present day. Stratigraphic analyses of these glacial and non-glacial sediments provide insight into the dynamicity of Late Pleistocene ice sheets; multiproxy analyses of three stratigraphic successions along the Albany River resulted in the recognition of at least three glacial advances from shifting ice centers within the QuĂŠbec sector of the Laurentide Ice Sheet during the Late Pleistocene. This dissertation contributes a chronological dataset for reconstructing the movement, timing and dynamics of Late Pleistocene ice sheets over North America, as well as paleoecological data for understanding the character and distribution of boreal peatlands during previous interstadial and interglacial periods.
Download or read book Dismantling the Laurentide Ice Sheet written by and published by . This book was released on 2013 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Laurentide Ice Sheet (LIS) existed as a dominant presence during the Last Glacial Maximum (LGM), covering nearly all of Canada and much of the northern United States. Rising boreal summer insolation and greenhouse gases ultimately led to the demise of the LIS. This dissertation presents new research on the LIS influence on, and response to, global climate. First, a sensitivity analysis on the effect of LIS surface elevation on modeled climate shows that the range of uncertainty in existing LIS topography reconstructions has major effects on modeled atmosphere and ocean circulation. Such significant differences in modeled climate as presented here have implications for boundary condition uncertainty in paleoclimate simulations. Second, a new chronology of initial LIS retreat is constrained using the in-situ cosmogenic 10Be in the surfaces of glacial erratics in Wisconsin. According to this chronology, ice began to pull back from its outermost extent approximately 23,000 years before present (23 ka), but sustained retreat did not occur until after ~20 ka. This timing is consistent with other chronologies, suggesting initial LIS retreat in response to rising insolation. Third, paired simulations of a fully-coupled atmosphere-ocean general circulation model and a surface energy balance model reconstruct the deglacial evolution of LIS surface melt. These simulations from 24 to 9 ka suggest that surface mass balance was stable across most of the deglaciation, which indirectly implicates dynamic discharge as the dominant source of volume loss prior to 11.5 ka. After 11.5 ka, a glaciological threshold was crossed with a heightened sensitivity to the elevated surface forcing of the early Holocene. Finally, a second 10Be chronology is presented for Quebec and Labrador to provide the timing and rate of LIS retreat during the final stages of the ice sheet in this area. This chronology suggests rapid retreat from the western margin of the Labrador Dome and slower retreat across the eastern and southern margins. This spatial distinction implies the breakup of the Labrador Dome shortly after the well known 8.2 ka event, indicating a dominant source of sea level rise from ice melt as opposed to the drainage of Lake Agassiz.
Download or read book Pliocene Pleistocene Evolution of the Laurentide Ice Sheet and North Atlantic Ocean Circulation written by R. Parker and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pleistocene Stratigraphy and Till Geochemistry of the Miramichi Zone New Brunswick written by Michel Lamothe and published by . This book was released on 1992 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mineral exploration in large parts of Canada is difficult because the bedrock is hidden beneath thick layers of glacially derived sediments. One technique to overcome this, called drift prospecting, identifies high concentrations of economically significant minerals or elements in the glacial sediments and helps to identify their bedrock sources. This project was designed to interpret Quaternary geology to assist in mineral development. This report shows how the geochemistry and lithology of the glacial sediments vary across the region and how the stratigraphy and provenance of those sediments can be interpreted so that geochemical anomalies or mineralized boulders may be traced back to their bedrock sources.
Download or read book Last Glacial deglacial Variability in Sea Surface Characteristics and Ice Sheet Activities in the Labrador Sea Baffin Bay written by Defang You and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the context of global warming, the accelerated melting of the Greenland Ice Sheet (GrIS) and Arctic sea ice in recent years has led to increased meltwater discharge and subsequent sea-level rise. The meltwater discharge may affect sea surface characteristics in the polar and subpolar regions and potentially yield significant influence on ocean circulation patterns. Additionally, the far-reaching implications of ocean forcings on ice sheet instability and sea ice retreat have also raised considerable attention. To enhance our understanding of the influences of meltwater discharge on abrupt climatic changes and interactions among ice sheet instability, sea ice variability, and sea surface characteristics, it is essential to investigate sedimentary records on different timescales beyond modern observation. To achieve these objectives, we conducted detailed paleoenvironmental reconstructions from three sediment cores: one obtained from the eastern Labrador Sea (Core MSM12/2-05-01) and two others from southern Baffin Bay (Core SL170 and SL174). This study provides new insights into variations in sea surface characteristics and their interactions with ice sheet activities in the Labrador Sea and Baffin Bay during the last glacial-deglacial-Holocene period. Meanwhile, our findings provide more information about the impact of freshwater forcing/ice sheet activities on abrupt climate changes. Furthermore, these findings highlight the significance of oceanic processes within the polar and subpolar regions and their contributions to paleoclimate changes.
Download or read book Dynamics of the Laurentide Ice Sheet written by Anders Eskil Carlson and published by . This book was released on 2006 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation concentrates on the controlling factors on the instability of the Laurentide Ice Sheet (LIS) and their effects on abrupt climate change. Northern Hemisphere climate fluctuated abruptly during the last deglaciation possibly related to variability in Atlantic meridional overturning circulation (AMOC) and reduced aerial extent of the LIS. Reductions in AMOC can be induced by changes in the hydrologic cycle which in turn may be controlled by instabilities in the LIS due to subglacial hydrology, sliding and till deformation. Sedimentological observations of the Tiskilwa Till, Illinois, and Sky Pilot Till, Manitoba determined that the LIS deposited these tills in a =1 m thick deforming layer as strain migrated upwards due to till accretion. These tills experienced high strain in a deforming layer thick enough contribute to ice sheet motion. Simulations of the subglacial hydrology of the James Lobe (JL) of the LIS suggest that the JL had little affect on regional groundwater flow and that subglacial aquifers were incapable of draining meltwater from the ice-till interface. However, a canal basal drainage system with canals up to 70 cm wide spaced 40 to 70 m apart could drain the ice-till interface keeping the JL coupled to its bed. To resolve the effects of LIS retreat on the hydrologic cycle, a suite of new freshwater routing proxies indicate that western Canadian Plains freshwater was routed to the St. Lawrence at the start of the Younger Dryas with an increase in base flow discharge sufficient to reduce AMOC. These proxies identified a previously unrecognized intra-Younger Dryas routing event at 12 ka, the impact of which indicates the tight coupling of AMOC, climate and the hydrologic cycle. To determine the role of the LIS in Holocene climate change, 10Be ages from western Quebec were used to date the final disappearance of the LIS at 6.8 ka following a period of rapid retreat and thinning that contributed to a rapid rise in sea level. The disappearance of the LIS initiated the Holocene Thermal Maximum, while the attendant reduction in freshwater runoff induced the formation of Labrador deep sea water.
Download or read book The Life of the Pleistocene Or Glacial Period written by Frank Collins Baker and published by . This book was released on 1920 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:
