Stratigraphic and sedimentological evidence for late Wisconsinan sub-glacial outburst floods to Laurentian Fan

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doi: 10.1016/j.palaeo.2006.10.029
Author(s): Piper, David J. W.; Shaw, John; Skene, Kenneth I.
Author Affiliation(s): Primary:
Geological Survey of Canada, Bedford Institute of Oceanography, Dartmouth, NS, Canada
Other:
University of Manitoba, Canada
University of Alberta, Canada
Dalhousie University, Canada
Volume Title: North American late-Quaternary meltwater and floods to the oceans; evidence and impact
Volume Author(s): Lewis, C. F. Michael, editor; Teller, James T.
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, 246(1), p.101-119; Tracing North American meltwater and floods to the North Atlantic, Halifax, NS, Canada, June 2003, edited by C. F. Michael Lewis and James T. Teller. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 69 refs.; illus., incl. sects., strat. cols., sketch maps
Summary: Sub-glacial meltwater produces a distinctive stratigraphic and sedimentological response on the continental margin. Seismo-stratigraphy of Laurentian Channel reveals thick till deposits at its seaward end that pass laterally into stratified sediment in deeper basins, that may record periods of water build up beneath the ice. Two scales of meltwater discharge are recognised: large scale that caused catastrophic erosion and transported large volumes of coarse sediment to the abyssal plain and smaller scale, yielding principally muddy sediment. Sub-glacial outburst floods from the Laurentian Channel ice stream delivered distinctive red sediment derived from Permian-Carboniferous strata of the Gulf of St. Lawrence directly to Laurentian Fan between ca. 17 and 14 14C ka, separate from North Atlantic Heinrich events. On levees of Laurentian Fan, three major pulses of meltwater plume muds are separated by intervals dominated by hemipelagic sediments. These meltwater intervals are recognised distally as periods of plume sedimentation on the Scotian Slope and ice-rafting of hematite-stained quartz to the North Atlantic Ocean. In channels of Laurentian Fan, at least one major sediment transport event is recognised that eroded the upper slope and the major fan valleys, depositing a bed of gravel at least 3 m thick in the characteristically wide fan valleys and thick sand on the Sohm Abyssal Plain. The same event was probably responsible for giant flute-like scours. The age of the gravel bed is directly constrained only by the presence of local overlying Holocene sediment. Much of the surface of the gravel bed was re-worked by the 1929 "Grand Banks" turbidity current. An erosional event on the upper slope, likely correlative with the flood-generated gravel bed, has been dated at 16.5 14C ka. Such large scale erosional flood events can be recognised back through several glacial cycles and have played an important role in the architectural evolution of Laurentian Fan.
Year of Publication: 2007
Research Program: ODP Ocean Drilling Program
Key Words: 20 Geophysics, Applied; 24 Surficial Geology, Quaternary Geology; Atlantic Ocean; Cenozoic; Cores; Erosion; Geophysical methods; Geophysical profiles; Geophysical surveys; Glaciation; Laurentian Fan; Leg 172; Lithostratigraphy; Marine environment; Marine sediments; Meltwater; North Atlantic; ODP Site 1063; ODP Site 1064; Ocean Drilling Program; Paleoenvironment; Pleistocene; Quaternary; Sediments; Seismic methods; Seismic profiles; Seismic stratigraphy; Sohm abyssal plain; Surveys; Turbidite; Upper Pleistocene; Upper Wisconsinan; Wisconsinan
Coordinates: N320000 N420000 W0500000 W0580000
Record ID: 2007039167
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands