中上扬子地区晚三叠世—侏罗纪砂岩构造意义及盆山耦合关系

TECTONIC SIGNIFICANCE OF SANDSTONES AND COUPLING RELATION OF BASIN AND MOUNTAIN IN THE LATETRIASSIC-JURASSIC IN THE MIDDLE AND UPPER YANGTZE REGION

刘云生 郭战峰 梁西文 杨振武

Liu Yunsheng Guo Zhanfeng Liang Xiwen Yang Zhenwu

中国矿业大学, 北京, 100032 2. 中国石化, 江汉油田分公司, 勘探开发研究院, 湖北, 潜江, 433124

China University of Mining Technology, Beijing 100083, China 2. Exploration & Development Research Institute of Jianghan Oilfield Branch Company, SINOPEC, Qianjiang, Hubei 433124, China

利用Dickinson等人建立的砂岩碎屑模型,对中上扬子地区晚三叠世—侏罗纪砂岩的组分特征进行研究,分析碎屑岩的物源区类型,认为晚三叠世—侏罗纪砂岩物源主要来自东秦岭—大别造山带、龙门山、江南逆冲带,具有明显的再旋回造山带属性,碎屑组分变化序列是盆缘造山带三期逆冲活动的沉积响应。通过分析晚三叠世—侏罗纪碎屑岩组分的构造意义,确定晚三叠世—侏罗纪中上扬子地区盆地性质为发育于碰撞造山、逆冲推覆带之前缘的前陆盆地,并探讨了东秦岭—大别造山带中生代的构造演化及其盆山耦合关系。

Based on the sandstone clastic model built by Dickinson et al,the characteristics of detrital composition of the Late Triassic-Jurassic sandstones in the Middle and Upper Yangtze region are studied to determine the types of source areas.It is presented that the main provenances of the Late Triassic-Jurassic basin comes from the East Qinling and Dabie orogenic belt,Longmenshan mountain and Jiangnan obduction zone.The main types of provenances attribute to the properties of recycled orogenic belt.The variational sequences of detrital compositions are the sedimentary responses to the three times of obduction of orogenic belt in the surrounding margin of basin.The analysis on the tectonic significance of detrital composition of the Late Triassic-Jurassic sandstones shows that the Late Triassic-Jurassic basin in the southern margin of the East Qinling and Dabie orogenic belt is a foreland basin located in the foreland of a collision orogen and thrusting nappe belt.The coupling relations of basin and mountain and Mesozoic tectonic evolution in the East Qinling and Dabie orogenic belt were also discussed in this paper.

中国石油化工股份有限公司科学技术开发研究项目(P02006)

https://doi.org/10.11781/sysydz200603201