Abstract
The effect of rapid thermal stress on the organic geochemistry of a siltstone intruded by a quartz-dolerite dyke and an oil shale intruded by an alkali-dolerite sill has been studied using optical petrography, Rock-Eval pyrolysis, gas chromatrography and gas chromatography-mass spectrometry. Maturity-dependent ratios derived from both the aliphatic and aromatic hydrocarbon fractions corroborate the observation of Raymond and Murchison (1988b) that the alkali-dolerite sills, which were intruded soon after sedimentation, had a lesser effect than the later quartz-dolerite intrusions. The maturity parameters based on the alkylnaphthalene and alkylphenanthrene isomer ratios are more suitable for studying maturity variations in heat-affected samples than those based on the commonly-used aliphatic biological markers. These aromatic compounds survive to higher ranks and the isomer ratios continue changing.
Original language | English |
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Pages (from-to) | 705-723 |
Number of pages | 19 |
Journal | Organic Geochemistry |
Volume | 18 |
Issue number | 5 |
DOIs | |
Publication status | Published - 1992 |
Externally published | Yes |
Keywords
- GC-MS' aromatic hydrocarbons
- igneous intrusion
- oil shale
- Scotland
- siltstone
- thermal maturation