摘要: |
从川西龙门山前陆盆地上三叠统-侏罗系沉积纪录可以看出,早中侏罗世以后整个盆地地层构型为一个板状特征,但在其近造山带一侧的盆地边缘又有大量的冲积粗碎屑存在,砂砾质粗碎屑楔形体在早中侏罗世主要位于龙门山前缘中北段,而晚侏罗世-早白垩世则明显地向南西方向迁移,盆地在不同时期、不同部位和不同成分的砂砾质粗碎屑楔形体的时空展布显示物源迁移明显,这是龙门山造山带走滑作用沉积的产物。 |
关键词: 龙门山前陆盆地 砂砾质粗碎屑楔形体 走滑作用 |
DOI: |
附件 |
投稿时间:2000-07-12 |
基金项目:国土资源部百人计划基金资助项目;四川省学术带头人后备基金资助项目;油气藏地质及开发工程国家重点实验室基金资助项目(PLN9732) |
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Quantitative statistics of sandy and gravelly wedges in the Longmenshan foreland basin, Sichuan |
XU Qiang, LIAO Shi-meng, ZHU Yong-gang, LIU De-chang, ZHU Tong-xing |
(1. Chengdu Institute of Geology and Mineral Resources, Chengdu 610082, Sichuan, China; 2. Northwest Sichuan Mining District, Sichuan Petroleum Administration Bureau, Jiangyou 621709, Sichuan, China) |
Abstract: |
The sedimentary records of the Upper Triassic-Jurassic strata in the Longmenshan foreland basin, western Sichuan show that from the Early and Middle Jurassic onwards, although the general stratigraphic configuration appears to be tabular, abundant alluvial coarse-grained fragments occur along the margin of the basin on the orogenic side.The sandy and gravelly wedges originated in the north-central segment of the Longmenshan front during the Early and Middle Jurassic, and the migrated southwestwards during the Late Jurassic-Early Cretaceous. The provenance migration is accounted for the strike-slipping of the Longmenshan orogenic belt; this is expressed by the spatio-temporal framework of the sandy and gravelly wedges of varying ages, localities and compositions. |
Key words: Longmenshan foreland basin sandy and gravelly wedges strike-slipping |