Organic geochemical study of the Upper Kimmeridge Clay of the Dorset type area |
| |
Authors: | Paul Farrimond Paul Comet Geoffrey Eglinton Richard P. Evershed Michael A. Hall David W. Park Anthony M.K. Wardroper |
| |
Affiliation: | Organic Geochemistry Unit, University of Bristol, School of Chemistry, Cantock''s Close, Bristol BS8 1TS, UK |
| |
Abstract: | Results are presented from an organic geochemical investigation of a suite of rock samples taken from the Upper Kimmeridge Clay near Kimmeridge, Dorset. All samples contain immature organic matter of marine origin, although one horizon, the Whitestone Band, contains an additional secondary input of partially biodegraded mature hydrocarbons, due to an oil seepage of unknown origin. With the exception of increased relative abundances of 4-methylsteroidal hydrocarbons in the more organic-rich samples, the immature molecular distributions are very similar, suggesting a consistent source of organic matter. The results are in agreement with the palaeoenvironmental model proposed by Tyson et al. (1979) for the deposition of the Kimmeridge Clay, where the different lithologies are controlled by a fluctuating oxic/anoxic boundary, with only the organic-poor mudstones being deposited in relatively oxygenated waters. |
| |
Keywords: | Geochemistry Kimmeridge Clay Palaeoenvironment Molecular distributions |
本文献已被 ScienceDirect 等数据库收录! |
|