Strontium Isotopic Signatures of the Streams and Lakes of Taylor Valley, Southern Victoria Land, Antarctica: Chemical Weathering in a Polar Climate

Authors: Lyons W.B.^{1, 2}; Nezat C.A.²; Benson L.V.³; Bullen T.D.⁴; Graham E.Y.⁵; Kidd J.⁵; Welch K.A.²; Thomas J.M.⁶

Source: Aquatic Geochemistry, Volume 8, Number 2, June 2002 , pp. 75-95(21)

Publisher: Springer

Abstract:

We have collected and analyzed a series of water samples from three closed-basin lakes (Lakes Bonney, Fryxell, and Hoare) in Taylor Valley, Antarctica, and the streams that flow into them. In all three lakes, the hypolimnetic waters have different ⁸⁷Sr/⁸⁶Sr ratios than the surface waters, with the deep water of Lakes Fryxell and Hoare being less radiogenic than the surface waters. The opposite occurs in Lake Bonney. The Lake Fryxell isotopic ratios are lower than modern-day ocean water and most of the whole-rock ratios of the surrounding geologic materials. A conceivable source of Sr to the system could be either the Cenozoic volcanic rocks that make up a small portion of the till deposited in the valley during the Last Glacial Maximum or from marble derived from the local basement rocks. The more radiogenic ratios from Lake Bonney originate from ancient salt deposits that flow into the lake from Taylor Glacier and the weathering of minerals with more radiogenic Sr isotopic ratios within the tills. The Sr isotopic data from the streams and lakes of Taylor Valley strongly support the notion documented by previous investigators that chemical weathering has been, and is currently, a major process in determining the overall aquatic chemistry of these lakes in this polar desert environment.

Language: English

Document Type: Research article

Affiliations: 1: Corresponding author, E-mail: lyons.142@osu.edu 2: Byrd Polar Research Center, The Ohio State University, Columbus, Ohio 43210-1002 3: U.S. Geological Survey, 3215 Marine Street, Boulder, Colorado 80303 4: U.S. Geological Survey, 345 Middlefield, Menlo Park, California 94025 5: Department of Geological Sciences, University of Alabama, Tuscaloosa, Alabama 35487 6: Desert Research Institute, 2215 Raggio Parkway, Reno, Nevada 89512

Publication date: 2002-06-01

• In this: publication
• By this: publisher
• In this Subject: Ecology ,  Geography ,  Geology
• By this author: Lyons W.B. ;  Nezat C.A. ;  Benson L.V. ;  Bullen T.D. ;  Graham E.Y. ;  Kidd J. ;  Welch K.A. ;  Thomas J.M.

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