Geochemical provenance analysis of fine-grained sediment revealing Late Miocene to recent Paleo-Environmental changes in the Western Ross Sea, Antarctica

Bulk chemical fine-grained sediment compositions from southern Victoria Land glacimarine sediments provide significant constraints on the reconstruction of sediment provenance models in the McMurdo Sound during Late Cenozoic time. High-resolution (similar to 1 ka) geochemical data were obtained with...

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Bibliographic Details
Published in:Global and Planetary Change
Main Authors: Monien, Donata, Kuhn, G. erhard, von Eynatten, Hilmar, Talarico, Franco Maria
Format: Article in Journal/Newspaper
Language:English
Published: 2012
Subjects:
XRF Core Scanner
Cenozoic
Ross Embayment
marine sediment
ANDRILL
Antarc*
Antarctica
Ice Shelf
McMurdo Ice Shelf
McMurdo Sound
Ross Island
Ross Sea
Victoria Land
Online Access:http://hdl.handle.net/11365/48215
https://doi.org/10.1016/j.gloplacha.2010.05.001
Description
Summary:Bulk chemical fine-grained sediment compositions from southern Victoria Land glacimarine sediments provide significant constraints on the reconstruction of sediment provenance models in the McMurdo Sound during Late Cenozoic time. High-resolution (similar to 1 ka) geochemical data were obtained with a non-destructive AVAATECH XRF Core Scanner (XRF-CS) on the 1285 m long ANDRILL McMurdo Ice Shelf Project (MIS) sediment core AND-1B. This data set is complemented by high-precision chemical analyses (XRF and ICP-OES) on discrete samples. Statistical analyses reveal three geochemical facies which are interpreted to represent the following sources for the sediments recovered in the AND-1B core: 1) local McMurdo Volcanic Group (MVG) rocks, 2) Transantarctic Mountain rocks west of Ross Island (W TAM), and 3) Transantarctic Mountain rocks from more southerly areas (S TAM). Data indicate in combination with other sediment facies analyses (McKay et al., 2009) and provenance scenarios (Talarico and Sandroni, 2009) that diamictites at the drill site are largely dominated by local sources (MVG) and are interpreted to indicate cold polar conditions with dry-based ice. MVG is interpreted to indicate cold polar condition with dry-based ice. A mixture of MVG and W TAM is interpreted to represent polar conditions and the S TAM facies is interpreted to represent open-marine conditions. Down-core variations in geochemical facies in the AND-1B core are interpreted to represent five major paleoclimate phases over the past 14 Ma. Cold polar conditions with major MVG influence occur below 1045 mbsf and above 120 mbsf. A section of warmer climate conditions with extensive peaks of S TAM influence characterizes the rest of the core, which is interrupted by a section from 525 to 855 mbsf of alternating influences of MVG and W TAM.

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