Abstract
A number of rare sterane hydrocarbons untypical of younger Phanerozoic petroleum systems have been found by gas chromatography-mass spectrometry in crude oils from the Nepa-Botuoba anteclise of the Siberian platform and the South Oman salt basin of the Arabian platform (Huqf family oils). Among regular steranes, a continuous series of C21 to C30 hydrocarbons including the previously unknown C23-C25 isomers have been identified. It has been noted that short-chain C21 and C22 steranes are represented by the most thermally stable pregnane species diginane and methyldiginane. Another series of steroids is represented by A-norsteranes, the structures demethylated at C10 (main fragment ion in the mass spectrum at m/z 203). Tricyclic hydrocarbons C26-C29 identified by m/z 219 have been attributed to the homologous series of 8,14-secosteranes. These chemofossils have a wide stratigraphic range of occurrence and, like modern minor secosterynes, can be associated with lipid membranes of sponge and their bacterial synbiotics.
Original language | English |
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Pages (from-to) | 186-194 |
Number of pages | 9 |
Journal | Petroleum Chemistry |
Volume | 55 |
Issue number | 3 |
DOIs | |
Publication status | Published - 15 May 2015 |
Externally published | Yes |
Keywords
- Arabian platform
- crude oil
- Siberian platform
- steranes