22. SOURCE AND MATURITY OF ORGANIC MATTER IN GLACIAL AND CRETACEOUS SEDIMENTS FROM PRYDZ BAY, ANTARCTICA, ODP HOLES 739C AND 741A1

Organic matter in Miocene glacial sediments in Hole 739C on the Antarctic Shelf represents erosional recycled con-tinental material. Various indications of maturity in bulk organic matter, kerogens, and extracts imply that an exposed section of mature organic carbon-rich material was present during...

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Bibliographic Details
Main Authors: Thomas J. Mcdonald, Mahlon C. Kennicutt Ii, Janina K. Rafalska, Richard G. Fox
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Subjects:
Antarctic
Prydz Bay
The Antarctic
Antarc*
Antarctica
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.612.5341
http://www-odp.tamu.edu/publications/119_SR/VOLUME/CHAPTERS/sr119_22.pdf
Description
Summary:Organic matter in Miocene glacial sediments in Hole 739C on the Antarctic Shelf represents erosional recycled con-tinental material. Various indications of maturity in bulk organic matter, kerogens, and extracts imply that an exposed section of mature organic carbon-rich material was present during the Miocene. Based on biomarker, n-alkane, and ker-ogen analysis, a massive diamictite of early Eocene/Oligocene age at Hole 739C contains immature organic matter. Vis-ual and pyrolysis analyses of the kerogens suggest a predominance of terrestrial organic matter in all samples from Hole 739C. A reversal of thermal maturities, i.e., more-mature overlying less-mature sections, may be related to redeposition generated from glacial erosion. Siliciclastic fluviatile sediments of Lower Cretaceous age from Hole 741A were analyzed. The organic matter from this hole contains immature aliphatic and aromatic biomarkers as well as a suite of odd carbon number-dominated n-alkanes. Visual examination and pyrolysis analysis of the kerogen suggests that predominantly immature terrestrial or-ganic matter is present at Hole 741A. The similarities between Hole 739C Unit V and Hole 741A suggest that the source of the organic matter in the glacial sediments in Unit V at Hole 739C could be Cretaceous in age and similar to sedi-ments sampled at Hole 741A in Prydz Bay.

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