Petroleum-generation timing and source in the northern Longmen Shan thrust belt, Southwest China: Implications for multiple oil-generation episodes and sources
| Autor: | Jie Wang, Shouzhi Hu, David Selby, Lianfu Mei, Liangbang Ma, Xiang Ge, Chuanbo Shen, Xiaoyan Ruan |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Permian
020209 energy Sichuan basin Energy Engineering and Power Technology Geology Orogeny 02 engineering and technology 010502 geochemistry & geophysics 01 natural sciences Paleontology chemistry.chemical_compound Fuel Technology Oil generation chemistry Geochemistry and Petrology Organic geochemistry 0202 electrical engineering electronic engineering information engineering Earth and Planetary Sciences (miscellaneous) Ordovician Petroleum Longmen shan 0105 earth and related environmental sciences |
| Zdroj: | AAPG bulletin, 2018, Vol.102(05), pp.913-938 [Peer Reviewed Journal] |
| ISSN: | 0149-1423 |
| Popis: | The temporal evolution of hydrocarbons (∼500 million bbl) and its relationship to the orogenic events of the Longmen Shan thrust belt have been extensively debated. The hydrocarbons occur as solid bitumen, as dykes and/or coatings within/along faults/fractures, and as present-day oil seeps. Here, utilizing organic geochemistry, we demonstrate that all of the bitumen exhibit similar organo-geochemical characteristics, and were sourced from the upper Neoproterozoic–lower Cambrian Doushantuo and Qiongzhusi Formations. In contrast, the organic geochemistry of the present-day oil seeps are distinct from that of the bitumen, and suggest that the source is the Permian Dalong Formation. Bitumen Re-Os data indicate that the upper Neoproterozoic–lower Cambrian Doushantuo and Qiongzhusi Formations underwent two temporally distinct oil-generation events; initial oil generation occurred during the Late Cambrian/Early Ordovician prior to the Caledonian orogeny, and secondly during the Jurassic (∼165 Ma) coinciding with the Indosinian-Yanshan orogenies. In contrast, the Re-Os data of the present-day oil seeps are too similar to yield a meaningful age, although the source is considered to have undergone hydrocarbon maturation between the Triassic and Jurassic. The temporal hydrocarbon evolution in the Longmen Shan thrust belt also provides an understanding of the hydrocarbon evolution and future exploration of the adjacent petroliferous Sichuan Basin. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|