00000nam 2200000za 4500 9.846579 CaOODSP 20241203113640 cr ||||||||||| 171103s1998 onca|||fo f000 0 eng d CaOODSP eng eng fre n-cn-on En13-5/97-110E-PDF Coakley, J. P. (John Phillip), 1940- Subsurface sediment profiles below Point Pelee [electronic resource] : indicators of postglacial evolution in western Lake Erie / by John P. Coakley, Allan S. Crowe and Patrice A. Huddart. Burlington, Ont. : National Water Research Institute, c1998. p. 88-99 ill. NWRI contribution ; 97-110 "For submission to the Canadian Journal of Earth Sciences". Reproduction of: Can. J. Earth Sci. 35: 88-99 (1998). Digitized edition from print [produced by Environment and Climate Change Canada]. Includes bibliographical references. "An extensive drilling program, undertaken along the western barrier bar at Point Canada, Pelee National Park, Ontario, yielded considerable subsurface sediment data relevant to the nature and lateral geometry of sedimentary units below the Point Pelee foreland. Four major sedimentary units were identified: a basal clay-rich till, a fine-grained glaciolacustrine sand, a medium-grained sand unit (subdivided into a poorly sorted shoreface sand) and an aeolian (dune) sand derived from the shoreface sand), and an organic marsh (gyttja) deposit. The present study confirms the existence of a planar, wave-eroded till surface below the southem portion of Point Pelee at an elevation of approximately 164 m asl. Following this low-water period in the basin, lake levels rose abruptly to an elevation several metres above 172 m asl. This resulted in erosion of the upper part of the glaciolacustrine sand during a later period of stable higher lake levels, perhaps coinciding with the Nipissing flood event (about 4000 BP). This resulted in a planar surface at approximately 169.5 m asl. Several radiocarbon dates on basal gyttja from the marsh (averaging 3200 BP) reflect a subsequent drop in levels to about 2-3 m below present levels. Though undated, the initiation of shoreface and dune sand deposition is roughly cofeval with the basal marsh deposits"--Abstract. Abstract in English and French. gccst Inland waters gccst Sediments Huddart, Patrice A. Crowe, Allan, 1952- Canada. Environment Canada. National Water Research Institute (Canada) NWRI contribution ; no. 97-110 (CaOODSP)9.844121 PDF 1.25 MB https://publications.gc.ca/collections/collection_2017/eccc/En13-5-97-110-eng.pdf