川东南志留系石牛栏组生物礁沉积特征

Sedimentary characteristics of the Silurian organic reefs from the Shiniulan Formation in southeastern Sichuan

摘要: 本文通过露头、钻井及地震剖面等,对川东南志留系石牛栏组沉积相进行了详细解剖。石牛栏组生物礁在地震剖面上呈丘状体,杂乱反射特征明显。石牛栏组两期礁滩旋回在平面上的展布特征为:早期台地边缘礁滩相以沉积生屑滩为主,有少量点礁分布其中;晚期台地边缘礁滩相以沉积大量点礁为主。川东南石牛栏组生物礁的沉积模式为碳酸盐岩缓坡模式,生物礁为发育在碳酸盐岩缓坡上的点礁群。

Abstract: In the light of outcrops, well logs and seismic profiles, the present paper gives a detailed exploration of the sedimentary facies in the Silurian Shiniulan Formation in southeastern Sichuan. The Silurian organic reefs in the Shiniulan Formation occur as knoll reefs and display chaotic reflection within the seismic profiles. In a planar view, the early platform-margin reef facies is dominantly made up of organic bank with a small amount of patch reefs. Till the late stage, abundant patch reefs occupy this facies. A carbonate ramp model for the organic reefs in the Shiniulan Formation shows that the organic reefs mostly appear as patch reef clusters on the carbonate ramps.