The Holocene environmental history of Lake Hoare, Taylor Valley, Antarctica, reconstructed from sediment cores

Abstract Up to 2.3 m long sediment sequences were recovered from the deepest part of Lake Hoare in Taylor Valley, southern Victoria Land, Antarctica. Sedimentological, biogeochemical, and mineralogical analyses revealed a high spatial variability of these parameters in Lake Hoare. Five distinct lith...

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Bibliographic Details
Published in:Antarctic Science
Main Authors: Wagner, Bernd, Ortlepp, Sabrina, Doran, Peter T., Kenig, Fabien, Melles, Martin, Burkemper, Andy
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 2011
Subjects:
Geology
Ecology, Evolution, Behavior and Systematics
Oceanography
Victoria Land
Taylor Valley
Fryxell
Hoare
Lake Fryxell
Washburn
Lake Hoare
Antarc*
Antarctic Science
Antarctica
Online Access:http://dx.doi.org/10.1017/s0954102011000125
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102011000125
Description
Summary:Abstract Up to 2.3 m long sediment sequences were recovered from the deepest part of Lake Hoare in Taylor Valley, southern Victoria Land, Antarctica. Sedimentological, biogeochemical, and mineralogical analyses revealed a high spatial variability of these parameters in Lake Hoare. Five distinct lithological units were recognized. Radiocarbon dating of bulk organic carbon samples from the sediment sequences yielded apparently too old ages and significant age reversals, which prevented the establishment of reliable age-depth models. However, cross correlation of the sedimentary characteristics with those of sediment records from neighbouring Lake Fryxell indicates that the lowermost two units of the Lake Hoare sediment sequences were probably deposited during the final phase of proglacial Lake Washburn, which occupied Taylor Valley during the late Pleistocene and early Holocene. High amounts of angular gravel and the absence of fine-grained material imply a complete desiccation with subaerial conditions in the Lake Hoare basin in the middle of the Holocene. The late Holocene (< c. 3300 calendar yr bp ) is characterized by the establishment of environmental conditions similar to those existing today. A late Holocene desiccation event, such as proposed in former studies, is not indicated in the sediment sequences recovered.

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