摘要
四川盆地西部在晚三叠世早期(卡尼期)为被动大陆边缘环境,沉积岩石单元为马鞍塘组。其中发育硅质海绵生物礁类型为点礁,分布在马鞍塘组的上部。点礁组合为礁基、礁核、礁翼、礁盖。现今出露礁体的分布主要沿着龙门山,呈NE-SW向展布。海绵礁体的分布与造礁生物海绵的自身特点、沉积环境、构造背景、生物组合、洋流等密切相关。本文基于此,认为生物礁分布在绵竹—江油一带,分布于大陆斜坡上,水体相对较深,呈宽带分布,礁体大小不一。现今礁体部分暴露于地表,部分被推覆体或上覆地层覆盖。该生物礁组合具有一定的油气成藏的地质条件,可以作为石油勘探的靶区。
The Maantang Formation in western Sichuan basin was probably located in the shelf of the passive continental margin in Upper Triassic. The kind of the Carnian siliceous reefs distributed along the Longmenshan Mountain is patch reef in western Sichuan. The complex of a reef is composed of reef base, reef core, reef flank and reef cap. The distribution of reefs is affected by such factors as properties of siliceous sponge, sediment envi- ronment, tectonic settings, biotic guild, temperature, oxygen-bearing zone, ocean current and suspend nutrient. Based on these factors, the authors hold that the reefs in a NE-SW extending belt are distributed in a continental shelf ca. 100 meters below the sea level. A part of the reefs is now exposed on the surface, and about 20 kinds of reefs have been discovered. The other part of the reefs might be covered by thrust blocks and overlying strata. It is evident that the reef complex is of good petroleum potential and exploration prospects.
出处
《地球学报》
EI
CAS
CSCD
北大核心
2009年第2期227-234,共8页
Acta Geoscientica Sinica
基金
中石化海相前瞻性课题:扬子西缘龙门-川滇构造系统及成藏效应研究项目(编号:G0800-06-ZS-282)资助
关键词
硅质海绵礁
上三叠统
川西
siliceous sponge reef
upper Triassic
western Sichuan
