Characteristics of Kerogens and Their Carbon Isotope Implications for the Shengli River Oil Shale in Qiangtang Basin, Northern Tibet
藏北羌塘盆地胜利河油页岩干酪根特征及碳同位素指示意义

The Shengli River oil shale in the southern part of northern Qiangtang depression within northern Tibet plateau has a EW-extending length of more than 34 km and a width of 9 m in the north-south direction.Such oil shale is of great importance in the assessment of oil and gas resources in Qiangtang basin.The oil shale has high kerogen contents and H/C ratios(1.11～1.19)and low O/C values(0.08～0.25),implying a fairly ideal source rock.The oil shale and interbedded marl from the Shengli River area in Qiangtang basin have a remarkably heavy Ckerogen isotopic composition.ranging in δ~(13)C values of the bulk organic matter from-20.79‰ to-2 1.78‰.The enrichment of ~(13)C in the Shengli River oil shale can be attributed to a combination of the high growth rate and the sedimentary environment,with the paleo-lagoon environment obviously controlling the spatial distribution and size of oil shale.