Deep-sea sedimentary record of the late Wisconsin cataclysmic floods from the Columbia River

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doi: 10.1130/0091-7613(1999)027<0463:DSSROT>2.3.CO;2
Author(s): Brunner, Charlotte A.; Normark, William R.; Zuffa, Gian G.; Serra, Francesca
Author Affiliation(s): Primary:
University of Southern Mississippi, Department of Marine Science, Stennis Space Center, MS, United States
U. S. Geological Survey, United States
Universita di Bologna, Italy
Volume Title: Geology (Boulder)
Source: Geology (Boulder), 27(5), p.463-466. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0091-7613 CODEN: GLGYBA
Note: In English. Univ. South. Miss., Dep. Mar. Sci., Contrib. No. 190. 19 refs.; illus., incl. 1 table, sketch maps
Summary: New results from Ocean Drilling Program Site 1037 and U.S. Geological Survey high-resolution seismic-reflection profiles confirm the great thickness, fast deposition rate, distant source, and convolute path of turbidites that fill the Escanaba Trough, the rift valley of the southernmost segment of the Gorda Ridge. Accelerator mass spectrometry 14C measurements provide the first direct dating of the Escanaba Trough turbidites, demonstrating an average deposition rate faster than 10 m/k.y. between 32 and 11 ka and as fast as 15 m/k.y. during the oxygen isotope stage 2 lowstand. In the upper 60 m of sediment, the petrology of turbidite sand beds, which are as much as 12 m thick, show that the dominant source for the turbidites is from the Columbia River, which is more than 800 km to the north, rather than from the much closer rivers of northern California. New high-resolution seismic-reflection profiles show that, except for areas of very recent volcanism, the entire Escanaba Trough below 3200 m water depth is floored by the turbidite sequence that was cored in the upper 60 m at Site 1037B. The ages of the upper 120 m of turbidites correspond with the ages of channeled scabland deposits associated with latest Quaternary jokulhlaups from glacial Lake Missoula. The age and source characteristics suggest that these megaturbidite beds in Escanaba Trough are most likely deposits formed by hyperpycnally generated turbidity currents as the largest of the Lake Missoula floods entered the sea.
Year of Publication: 1999
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Absolute age; C-14; Carbon; Cenozoic; Channeled Scabland; Columbia Plateau; Columbia River; Correlation; Currents; Dates; Deep-sea environment; Depositional environment; East Pacific; Escanaba Trough; Foraminifera; Geophysical methods; Geophysical profiles; Geophysical surveys; Glacial environment; Glacial features; Glacial lakes; Glaciolacustrine environment; Heavy minerals; Hemipelagic environment; High-resolution methods; Invertebrata; Isotopes; Jokulhlaups; Lacustrine environment; Lake Missoula; Lakes; Leg 169; Lithostratigraphy; Marine environment; Marine sediments; Megaturbidite; North Pacific; Northeast Pacific; ODP Site 1037; Ocean Drilling Program; Pacific Ocean; Paleofloods; Planktonic taxa; Pleistocene; Protista; Provenance; Quaternary; Radioactive isotopes; Reflection methods; Sediment transport; Sedimentation rates; Sediments; Seismic methods; Seismic profiles; Surveys; Turbidite; Turbidity currents; United States; Upper Pleistocene; Upper Wisconsinan; Wisconsinan
Coordinates: N410000 N410000 W1272000 W1273000
Record ID: 1999037079
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