28 August 2008 Biomarker indicators of bacterial activity and organic fluxes during end Triassic mass extinction event
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Abstract
Lipid biomarker analyses of sedimentary organic matter from a marine Triassic-Jurassic (T-J) section at Queen Charlotte Islands, British Columbia reveal significant bacterial activity and microbial community changes that coincide with faunal extinctions across the T-J boundary. Bacterial activity is indicated by the 25-norhopane biodegradation index (25-norhopanes / 25-norhopanes+regular hopanes). Microbial community changes is revealed by variations in relative abundance of 2-methylhopane which is mainly generated from cyanobacteria. The 2-methylhopane index (2-methyl hopane/ C30 hopane + C29 25-norhopane) increases above the radiolarian based T-J boundary, and coincides with changes in the 25-norhopane index. The data reveal a complex microbial event involving both autotrophic and heteorotrophic bacteria responding to variations in allochthonous organic matter and nutrient supply.
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Dan Jiao, Dan Jiao, Randall S. Perry, Randall S. Perry, Mike H. Engel, Mike H. Engel, Mark A. Sephton, Mark A. Sephton, } "Biomarker indicators of bacterial activity and organic fluxes during end Triassic mass extinction event", Proc. SPIE 7097, Instruments, Methods, and Missions for Astrobiology XI, 709709 (28 August 2008); doi: 10.1117/12.796160; https://doi.org/10.1117/12.796160
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