Petrography and Geochemistry of Carbonate Sediments on the Ross Sea Continental Shelf, Antarctica
This investigation integrates petrography, geochemistry, and radiocarbon dating to examine diagenetic processes and their effect on preservation of carbonate sediments in cold-water settings. Petrographic observation of coarse grains in thin section revealed evidence for widespread bioerosion. Micro...
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DigitalCommons@University of Nebraska - Lincoln
2013
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| Online Access: | https://digitalcommons.unl.edu/embargotheses/52 https://digitalcommons.unl.edu/context/embargotheses/article/1072/viewcontent/4_22_13_Night_Draft.pdf |
| Summary: | This investigation integrates petrography, geochemistry, and radiocarbon dating to examine diagenetic processes and their effect on preservation of carbonate sediments in cold-water settings. Petrographic observation of coarse grains in thin section revealed evidence for widespread bioerosion. Microbores in skeletal carbonate grains remain empty, increasing surface area, leaving them susceptible to further breakdown. Examination of the fine fraction indicated much of the fine carbonate consists of bioeroded bryozoan fragments. Observations indicate bioerosion leads to fragmentation. Bottom currents extend exposure time on the seafloor and winnow the fine fraction. The noncalcareous fine fraction is composed of reworked Miocene-Recent marine diatoms, foraminifera, sponge spicules, and siliciclastic debris. Radiocarbon analyses of skeletal grains yielded ages: >22.7±0.9ka (n=9) and Advisor: Tracy Frank |
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