塔里木盆地东部南华系-寒武系黑色岩系地球化学特征及形成与分布

近年来，随着油气勘探向深层-超深层领域拓展，古老层位的烃源岩逐渐成为研究热点。塔里木盆地周缘广泛出露的前寒武地层为古老烃源岩及其发育背景研究提供了基础。本文主要介绍了塔东地区南华系、震旦系和寒武系三套烃源岩，通过对库鲁克塔格地区野外露头及岩芯资料的综合分析，采用有机地球化学和无机地球化学手段对烃源岩质量以及烃源岩发育环境进行了评价，认为南华系特瑞艾肯组、震旦系水泉组、寒武系西大山组为主要烃源岩发育层位。特瑞艾肯组烃源岩TOC分布在0.22%~2.80%，平均值1.65%，Ro平均值为1.28%~1.60%；水泉组烃源岩TOC分布在0.22%~0.79%，平均值为0.49%；Ro分布在1.37%~1.93%之间（均值1.72%）；西大山组烃源岩TOC分布在0.15%~1.45%，平均值0.47%。结合地震资料对裂陷结构进行追踪，初步对塔里木盆地东部三套烃源岩的分布范围进行了限定。针对塔里木盆地新元古代盆地演化背景，运用C、O、Sr同位素及微量元素等，对三套黑色岩系形成环境与发育机制进行分析；并对库鲁克塔格地区的冰期事件进行了的限定，认为塔东地区南华-寒武纪至少发生过三期冰期事件，塔东地区冰碛岩地层的划分可以为全球前寒武地层对比提供依据。

Geochemical characteristics, formation and distribution of the Nanhua-Cambrian black rock series in the eastern Tarim Basin

In recent years, deep and ancient source rocks have gradually attracted considerable attention with the expansion of oil and gas exploration to the deep strata. The Precambrian strata exposed at the margin of the Tarim Basin provide a basis for the study of ancient hydrocarbon source rocks and their development backgrounds. Here, we characterized three sets of source rocks from the Nanhua to Cambrian systems after systematic analysis of outcrops and core data from the Kuruktage region and evaluated their qualities and development environments based on both organic and inorganic geochemical data. The research data show that the Tereeken Formation, the Shuiquan Formation and the Xidashan Formation are the dominant Nanhua-Cambrian hydrocarbon-generating source rocks in this area. The TOC of the source rocks in the Tereeken Formation has TOC contents of 0.22%~2.80% (averaged at 1.65%) and Ro values of 1.28%~1.60%. The source rocks in Shuiquan Formation has TOC contents of 0.22%~0.79% (averaged at 0.49%) and Ro values of 1.37%~1.93% (mean=1.72%). The source rocks of Xidashan Formation exhibits TOC values of 0.15%~1.45% (mean=0.47%). Based on seismic data, we preliminarily constrained the distribution of the source rocks of the Nanhua to Cambrian systems in the eastern Tarim Basin. Combined with evolutionary history of the Tarim Basin during the Neoproterozoic, C, O and Sr isotopic data were used to reveal the development environment and formation mechanism of the studied source rocks and constrain the glaciations in the Kuruktag area. It is believed that at least three glaciations occurred in Tarim Basin during the Nanhua to Cambrian periods, which may provide a basis for the global stratigraphic correlation of the Precambrian strata.