Comparison of Tarim and central Asian FSU basins, II: Differences in hydrocarbon systems and possible explanations
- Amoco Production Co., Houston, TX (United States)
If the Tertiary crustal shortening and indentation in the Pamirs is restored palinspastically, it would be evident that the Central Asian basins in the FSU (including Amu Darya, Tajik, Fergana, and Syr Darya) in the west and the Tarim basin in the cast probably shared many similarities in their geological history after becoming part of the Eurasia continent in the Late Paleozoic. For example, both areas contain significant amounts of coal-bearing Jurassic sequences, and a marine connection no doubt existed between the two during the maximum marine transgression period of Late Cretaceous and Early Tertiary. A direct comparison is more difficult for the Paleozoic sequences because in the Central Asia basins, they are either buried too deeply or highly metamorphosed in the outcrops. It is interesting to note that these basins exhibit vast differences in the age and type of source and reservoir rocks. For the Tarim basin, most of the source rocks are Paleozoic (Ordovician and Carboniferous) and marine in nature, whereas in the Central Asian basins, the dominant source rocks are Jurassic and younger and include both marine and non-marine sequences. Similarly for the reservoir rocks, most of the hydrocarbons found in the Tarim basin is from the Paleozoic, (such as Devonian and Carboniferous clastics/carbonates), whereas in Amu Darya and Fergana basins, the reservoir rocks are dominated by Jurassic carbonates and Paleogene clastics respectively. This presentation will highlight these differences and address the probable causes mainly from the view points of tectonics and paleogeography. We conclude that the dominant effect is the Early Tertiary India-Asia collision, which caused significant differences in the distribution and thickness of the post-collisional clastic sediments, which in turn resulted in different maturation and migration history.
- OSTI ID:
- 6576232
- Report Number(s):
- CONF-960527-; CODEN: AABUD2
- Journal Information:
- AAPG Bulletin, Vol. 5; Conference: Annual convention of the American Association of Petroleum Geologists, Inc. and the Society for Sedimentary Geology: global exploration and geotechnology, San Diego, CA (United States), 19-22 May 1996; ISSN 0149-1423
- Country of Publication:
- United States
- Language:
- English
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Comparison of Tarim and central Asian FSU basins, I: Phanerozoic paleogeography
Comparison of Tarim and central Asian FSU basins, I: Phanerozoic paleogeography