四川盆地古生代生物礁滩特征及发育控制因素

在古生代,生物礁从老到新主要发育在早寒武世、早志留世及晚二叠世地层中。地理分布上,它们分别产于四川盆地北、东北缘大巴山、米仓山地区（早寒武世礁）、四川盆地南北缘（早志留世礁）以及鄂西渝东、川东北地区（晚二叠世礁）。早寒武世礁滩组合包括古杯礁、灰泥丘及鲕粒滩,造礁生物为古杯、蓝藻类微生物,附礁生物有三叶虫、腕足类、海百合及海绵等。由于受海平面波动的控制,生物礁具有旋回性,并从西向东,层位逐渐抬升。早志留世礁有点礁、灰泥丘及层状礁等,其分布受古陆影响的陆源碎屑-碳酸盐缓坡的控制,也与海平面波动有关。晚二叠世生物礁有点礁、台缘礁及灰泥丘,其分布也受古地貌格局和海平面波动的控制。

Characteristics and controlling factors of development of Paleozoic reef-banks in the Sichuan basin

Paleozoic reefs are mainly distributed in Early Cambrian, Early Silurian and Late Permian strata in the Sichuan basin. Geographically, they occur in the Daba and Micang mountains on the northern and northeastern margins of the Sichuan basin (Early Cambrian reefs), on the northern and southern margins of the Sichuan basin (Early Silurian reefs) and western Hubei, eastern Chongqing and northeastern Sichuan (Late Permian reefs). The Early Cambrian reef-bank association includes patch reefs, lime-mud mounds and...