Lacustrine sedimentation and paleoclimate, Pleistocene-Holocene Lake Terreton, northeastern Snake River plain, Idaho

Author(s): Gianniny, Gary L.; Thackray, Glenn D.
Author Affiliation(s): Primary:
Bucknell University, Department of Geology, Lewisburg, PA, United States
Idaho State University, United States
Volume Title: Geological Society of America, 1997 annual meeting
Source: Abstracts with Programs - Geological Society of America, 29(6), p.437; Geological Society of America, 1997 annual meeting, Salt Lake City, UT, Oct. 20-23, 1997. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0016-7592 CODEN: GAAPBC
Note: In English
Summary: Linkages between continental glacial records and deep-sea records of climatic fluctuations have been limited by the discontinuity of continental sedimentation and by the scarcity of chronological control. The nature of western North American climate response to climatic events recognized in DSDP cores may be enhanced by a high resolution record of lacustrine sedimentation recovered from four 50 meter-deep cores near the margin of Pleistocene-Holocene Lake Terreton on the northeastern Snake River Plain. Like other closed Great Basin lakes, precipitation/evaporation balances are the primary control on lake depth such that inferred Lake Terreton depth can be used as a first-order proxy for climate variability. In each of the cores basal lacustrine sediments are overlain by two basalt flows (10 m thick), which are overlain by 35 m of lacustrine, eolian and fluvial sediments. Within the upper 35 m, six post 150 ka pulses of lacustrine deposition are recorded. Clays and silts below the basalts were thermally altered and yield preliminary thermoluminescence ages of 136±13 ka and 153±13 ka. Additional dating in progress will further constrain the temporal framework of these deposits. These dates provide minimum average sedimentation rates for this portion of the Lake Terreton basin approaching 0.5-1.0 mm/100 years. The thickest accumulation of well-laminated lacustrine clays occurs between core depths of 20 m to 14 m and may be associated with pluvial conditions of isotope stage 4 or late stage 6. Ostracodes (Candona, Cypridopsis) from this interval suggest well circulated lacustrine conditions. A shift to more sand-rich sediments with abundant rounded clay intraclasts in the upper 14 m of core is inferred to indicate higher energy deposition in shallow lakes and playas. Thus, deep lake conditions appear to have characterized isotope stages 6 and/or 4, while shallow lake conditions characterized stage 2. These preliminary results concur with other climate proxies suggesting that isotope stage 2 was relatively dry in the northern Rocky Mountains.
Year of Publication: 1997
Research Program: DSDP Deep Sea Drilling Project
Key Words: 24 Surficial Geology, Quaternary Geology; Arthropoda; Basin and Range Province; Cenozoic; Cores; Crustacea; Glacial environment; Great Basin; Holocene; Idaho; Invertebrata; Lacustrine environment; Lake Terreton; Lake sediments; Mandibulata; North America; Northern Rocky Mountains; Ostracoda; Paleoclimatology; Paleohydrology; Paleolimnology; Pleistocene; Quaternary; Rocky Mountains; Sedimentation; Sedimentation rates; Sediments; Snake River plain; Thermoluminescence; Thickness; United States
Record ID: 1998051654
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States

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