中文摘要：

早三叠世作为地球发展史上一个高度的反常时期,人们对其关注程度远不及二叠纪/三叠纪界线。海相碳酸盐的碳、锶同位素组成与演化是了解重大突变期的生态环境事件和地球过程的重要切入点。根据前人公布的川东地区早三叠世锶、碳同位素数据,绘制同位素演化散点图,根据曲线的演化特征以及不同地区的对比,分析其控制因素和地质过程。研究表明,川东地区早三叠世锶同位素演化曲线单调上升,具有很高的全球一致性,由河流注入到海水的高放射成因的锶含量增加是加剧^87Sr/^86Sr比值单调上升的主要原因。碳同位素演化曲线在短时间内发生的一系列高频率、大幅度波动,大量的磷酸盐注入海洋使菌藻类大量繁殖,海洋的初级生产力增强,有机碳埋藏量增大,使δ^13C偏高。甲烷水合物吸收与释放等暂时性效应不是引起曲线来回波动的主要因素,海洋水体倒转等持续性效应可以很好地解释曲线异常,但对其驱动机制有待进一步研究。此外δ^13Ccarb和δ^13Corg的同步研究并参考早寒武世是下一步研究的重点。

英文摘要：

The Early Triassic is a highly anomalous period in earth history, but little attention was given to this period in comparison with the Permian-Triassic boundary. The evolution of carbon and strontium isotopes of marine carbonate can give the information about the ecosystem function and environment change of the transitional period. According to the data concerning carbon and strontium isotopes during Early Triassic obtained from eastern Sichuan area, the isotope scattergram can be drawn, with which we can analyze the geological processes as well as the controlling factors. As shown by the scattergram, strontium isotope evolution curve increases monotonously, which is in high consistency with features of other areas in the world, suggesting that the increased content of highly radiogenic strontium was the leading factor for this phenomenon. In the carbon isotope scattergram, there exists violent fluctuation, which can be attributed to the migration of a large quantity of phosphate into the ocean which caused the blooming of the algae and the enhancement of the ocean primary productivity. The absorption and release of methane hydrate were not the main factors causing the fluctuation, whereas the persistent effects, such as the sea water reversion, can well explain the anomalous curve. Nevertheless, the mechanism should be further investigated. In addition, it is necessary to combine the organic carbon with the inorganic carbon and to consider the Early Cambrian.