摘要
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。
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 Per^nian reefs）. The Early Cambrian reef-bank association includes patch ree~, lime-mud mounds and oolitic shoals. Reef-building organisms are archaeocyatha and cyanobacteria and organisms attached to reefs are trilobites, brachipods, crinoids and sponges. Controlled by sea-level fluctuation, reefs have cycliciy and from west to east the horizons are raised gradually.Early Silurian reefs include patch reef~, lime-mud mounds and biostromes. Reef-building organisms are mostly corals, stromatoporoids, polyzoa and cyanobateria. Their distribution are controlled by terrigenous clastic- carbonate gentle slope affected by oldland and also related to sea-level fluctuations. Late Permian reef~ ＇are inner platform patch reefs and platform marginal reet~. Reef-building organisms are primarily sponges. Reef growth and distribution have a close relation with the paleogeomorphological framework and sea level fluctuations.
出处
《中国地质》
CAS
CSCD
2008年第5期1017-1030,共14页
Geology in China
基金
四川省重点学科建设项目基金(SZD0414)资助
关键词
生物礁
发育与分布
早古生代
四川盆地
reef
development and distribution
Early Paleozoic
Sichuan basin
