Abstract: The Upper Permian-Lower Triassic outcrops in Duwa area of Helian, Xinjiang are dominated by thick dark shale. The sedirnenlary center is at north areal coverage, the source area is at the outcrop area in south o[ Duwa faulting. The former has decper sedimentary environl-ment than the lalter, so ils dark shale is thickened and distributed range is enlarged. The geochemical indicators for hydrocarbon generation from outerop samples are nol high. but there exist Botryvococcus fossils in marry intervals and sections. which are rich in somc horizons, with relative slable and exlensive distribution in plane. It means that the dark shale should be of higher capability or potential for hydrocurbon generalion. and will be as important strata for hydrocarbon source rock evalualiorl in Hetian region, Xinjiang.

Key words: Xinjiang, Upper Permian, Lower Triassic, Botryococcus, source rock