Erosion of the Laurentide Region of North America by Glacial and Glaciofluvial Processes
- 1 March 1985
- journal article
- Published by Cambridge University Press (CUP) in Quaternary Research
- Vol. 23 (2), 154-174
- https://doi.org/10.1016/0033-5894(85)90026-2
Abstract
Collection of seismic reflection data from continental margins and ocean basins surrounding North America makes it possible to estimate the amount of material eroded from the area formerly covered by Laurentide ice sheets since major glaciation began in North America. A minimum estimate is made of 1.62 × 106 km3, or an average 120 m of rock physically eroded from the Laurentide region. This figure is an order of magnitude higher than earlier estimates based on the volume of glacial drift, Cenozoic marine sediments, and modern sediment loads of rivers. Most of the sediment produced during Laurentide glaciation has already been transported to the oceans. The importance of continental glaciation as a geomorphic agency in North America may have to be reevaluated. Evidence from sedimentation rates in ocean basins surrounding Greenland and Antarctica suggests that sediment production, sediment transport, and possibly denudation by permanent ice caps may be substantially lower than by periodic ice caps, such as the Laurentide. Low rates of sediment survival from the time of the Permo-Carboniferous and Precambrian glaciations suggest that predominance of marine deposition during some glacial epochs results in shorter lived sediment because of preferential tectonism and cycling of oceanic crust versus continental crust.Keywords
This publication has 47 references indexed in Scilit:
- New Evidence from Beneath the Western North Atlantic for the Depth of Glacial Erosion in Greenland and North AmericaQuaternary Research, 1980
- The stratigraphy and structure of the Laurentian Cone regionCanadian Journal of Earth Sciences, 1979
- Provenance of Mesozoic and Cenozoic sediments from the Labrador and western Greenland continental marginsCanadian Journal of Earth Sciences, 1978
- Late Quaternary Glaciation of the Eastern Queen Elizabeth Islands, N.W.T., Canada: Alternative ModelsQuaternary Research, 1976
- A case against deep erosion of shields by ice sheetsGeology, 1976
- Laurentide Ice Sheet Meltwater Recorded in Gulf of Mexico Deep-Sea CoresScience, 1975
- Structure and morphology of the west Reykjanes basin and the southeast Greenland continental marginMarine Geology, 1975
- Chemical weathering in the temperate glacial environment of the Northern Cascade MountainsGeochimica et Cosmochimica Acta, 1972
- Growth of the Bengal Deep-Sea Fan and Denudation in the HimalayasGSA Bulletin, 1971
- The Sediment Yield of Major Rivers of the WorldWater Resources Research, 1968