Mather, I. D., Wellsbury, Peter, Parkes, Ronald John and Maxwell, J. R. 2001. Purge-trap analysis of sediments of the western Woodlark Basin, Sites 1109 and 1115. Proceedings of the Ocean Drilling Program Scientific Results 180 , 18. 10.2973/odp.proc.sr.180.171.2001 |
Abstract
Low molecular weight hydrocarbon (LMWH) distributions were examined in sediments from Sites 1109 and 1115 in the western Woodlark Basin using purge-trap thermal adsorption/desorption gas analysis. A number of different hydrocarbon components >C1, which were not detected during shipboard gas analysis, were detected at both sites using the purge-trap procedure. Concentrations of ethane, propane, and butane remained relatively low (<100 pmol/g) throughout Site 1109 and had no consistent trend with depth. In contrast, the longer-chain components increased in concentration with depth. Hexane concentrations rose to 716 pmol/g at the base of the site with a concomitant increase in both 2-methyl- and 3-methylpentane. At Site 1115, concentrations of ethane, propane, butane, and isobutylene + 1-butene remained low (<60 pmol/g) throughout the site and again had no consistent trend with depth. 2-Methylpentane, 3-methylpentane, and hexane concentrations had a subsurface maximum that coincided with sediments containing abundant plant-rich material. The LMWH downhole profiles plus low in situ temperatures suggest that the LMWH components were formed in situ by low-temperature biological processes. Purge-trap analysis has indicated the presence of some unexpected deep low-temperature bacterial reactions, which demonstrates that further analysis of LMWH may provide valuable information at future Ocean Drilling Program sites.
Item Type: | Article |
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Date Type: | Publication |
Status: | Published |
Schools: | Earth and Environmental Sciences |
Subjects: | Q Science > QE Geology Q Science > QR Microbiology |
Uncontrolled Keywords: | deep biosphere, hydrocarbons |
Publisher: | Ocean Drilling Program |
ISSN: | 1096-7451 |
Last Modified: | 04 Jun 2017 02:05 |
URI: | https://orca.cardiff.ac.uk/id/eprint/8673 |
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