Gianniny, Gary L. and Thackray, Glenn D. (1997): Lacustrine sedimentation and paleoclimate, Pleistocene-Holocene Lake Terreton, northeastern Snake River plain, Idaho

Leg/Site/Hole:
Identifier:
1998-051654
georefid

Creator:
Gianniny, Gary L.
Bucknell University, Department of Geology, Lewisburg, PA, United States
author

Thackray, Glenn D.
Idaho State University, United States
author

Identification:
Lacustrine sedimentation and paleoclimate, Pleistocene-Holocene Lake Terreton, northeastern Snake River plain, Idaho
1997
In: Anonymous, Geological Society of America, 1997 annual meeting
Geological Society of America (GSA), Boulder, CO, United States
29
6
437
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+ or -13 ka and 153+ or -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.
English
Coverage:Geographic coordinates:
North:65.0000
West:-155.0000East: -103.0000
South:32.0000

Quaternary geology; Arthropoda; Basin and Range Province; Cenozoic; cores; Crustacea; glacial environment; Great Basin; Holocene; Idaho; Invertebrata; lacustrine environment; lake sediments; Lake Terreton; 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;

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