地质学报2024，Vol.98Issue(2)：530-543,14.DOI:10.19762/j.cnki.dizhixuebao.2023262
北羌塘胜利河地区布曲组优质烃源岩形成环境与有机质富集机制
Formation environment and organic matter enrichment mechanism of high-quality source rocks in the Buqu Formation in the Shenglihe area,northern Qiangtang basin
摘要
Abstract
The Qiangtang basin is the Mesozoic marine sedimentary basin with the lowest degree of oil and gas exploration in the new land area,and its main source rocks have not been clearly understood.In this paper,the organic geochemistry and element geochemistry of the source rocks of the Middle Jurassic Buqu Formation in Shenglhe area have been systematically studied,and the formation environment and organic matter enrichment mechanism of the source rocks of the Buqu Formation have been discussed.This provides a theoretical basis for predicting the distribution of high-quality source rocks in the Middle Jurassic Buqu Formation in the North Qiangtang depression.The source rocks of the Buqu Formation in Shenglihe area have high abundance of type Ⅱ of organic matter in mature stage.During the Buqu period,the climate was arid and hot,and the primary productivity level of the study area was relatively high,which was a weakly confined basin with shallow water,high salinity and oxygen-poor depositional environment.During the Buqu period,large-scale transgression occurred in the Qiangtang basin,and the study area was adjacent to the central uplift.A large number of nutrients such as phosphorus and iron from terrigenous input and hydrothermal activities were carried into the ocean,resulting in higher primary productivity,which was the main controlling factor for the enrichment of organic matter in high-quality source rocks of the Buqu Formation in the North Qiangtang depression.The study area is located in the minimum oxygen-containing zone of the North Qiangtang depression,which is conducive to the anoxic death and burial of a large number of planktons.Through the analysis of organic matter enrichment mechanism,the coastal shelf slope zone of the North Qiangtang depression may be a favorable area for the distribution of high-quality source rocks in the Middle Jurassic Buqu Formation.关键词
有机质富集/优质烃源岩/古生产力/胜利河/北羌塘坳陷Key words
organic matter enrichment/high-quality source rock/palaeoproductivity/Shenglihe area/northern Qiangtang basin引用本文复制引用
陈程,吴珍汉,赵为永,王利,季长军,赵珍,张浩,龚赞..北羌塘胜利河地区布曲组优质烃源岩形成环境与有机质富集机制[J].地质学报,2024,98(2):530-543,14.基金项目
本文为国家自然科学基金项目(编号 42102201)和中国地质调查项目(编号 DD20221660-2)联合资助的成果. （编号 42102201）
