塔里木盆地上寒武统SPICE事件记录及其油气地球化学响应

近年来有关上寒武统SPICE（Steptoean Positive Carbon Isotope Excursion）事件的研究为一热点，其引发机制及生物地球化学意义是主要的探讨课题。塔里木盆地也检出了该事件的沉积记录，其无机碳酸盐岩和残余干酪根之间稳定碳同位素的协同正向漂移是否与目前台盆区发现的富集13C的油气藏具有成因联系？其沉积环境、生物发育特征等都是值得深入研究的内容。本工作选择塔里木盆地野外露头和不同沉积环境的钻井岩心/岩屑样品系统对比分析其SPICE事件记录特征，探讨无机碳酸盐岩与残余干酪根稳定碳同位素协同演化的成因机制；精细对比分析残余干酪根的地球化学特征，结合沉积环境演化、生物发育特征等信息综合探讨SPICE事件与台盆区富集13C油气藏之间的成因联系。本工作针对SPICE事件中同位素漂移成因机制的探讨具有理论研究意义，探讨其在塔里木盆地的油气地球化学响应具有重要的实践意义。

SPICE (Steptoean Positive Carbon Isotope Excursion) event is currently a hot issue for the researchers in this field over the world, among which its biogeochemical significance is an important topic. This event has been reported determined from the upper Cambrian strata in the Tarim Basin, NW China. So some issues arise with this event: Whether this event is associated with the 13C enriched crude oils recently more and more found in Tarim basin? Is it possible that within some areas the upper Cambrian strata could develop source rocks linked with the SPICE event? If yes how about the sedimentary environment, biomass evolution, and so on? This proposal is targeted to study the geochemical recording of SPICE event in the Tarim basin, and then some outcrop profiles and a few drilling cores will be chosen for detailed characterization concerning the inorganic/organic geochemical properties distributed along the profiles. The most important tasks including that to investigate the co-variation mechanism of stable carbon isotopes between the inorganic carbonate and the organic kerogens during the SPICE deposition period, to elucidate the relationship of this event to the 13C enriched crude oil reservoirs occurred in the basin, and to appraise the possibility of some upper Cambrian strata developing the source rocks and their contribution to the oil reservoirs. Therefore the outcomes of this project will be helpful for the clarification of some fundamental issues associated with the SPICE event, and evidently of fairly good application significances to the oil/gas exploration research work in the Tarim basin.