166 / 2019-06-04 10:17:00

The sedimentological characteristics and key control factors of the Cambrian microbial carbonates

Microbial carbonate;Ecosystems;key control factors; The Cambrian.

Cambrian is an important transition and most developed period of phanerozoic for the microbial carbonates. Microbial-archaeocyath reefs occurred in Terreneuvian and Epoch 2, while microbial-lithistid reefs occurred in Epoch 3 and Furongian. China is one of the most important regions for the Cambrian microbial carbonates developments. In Tarim Plate, Eastern North China Plate, and Yangtze Plate, microbial carbonates were well developed in this period, but the typical types of microbial carbonates were slightly different. Compared with Yangtze Plate, stromatolites are more prosperous in Tarim Plate and Eastern North China Plate, and dendritic thrombolites are more developed in Eastern North China Plate. The disappearance of the ancient archaeocyath reef in different areas has a hysteresis, which disappeared in Eastern North China later than in the Yangtze region. The archaeocyath reef is less developed in Tarim region. Epoch 3 is the period when microbial carbonates are generally developed, corresponding to the Avatag Formation in Tarim region of China, Zhangxia Formation in Eastern North China, and Qinjamiao Formation in Yangtze region. Cambrian microbial carbonates are affected by global sea level, biological explosion, Kalkarindji volcanic province, carbon dioxide concentration, and terrigenous clastic supply, etc., and the increase of terrigenous clastic supply may be an important reason for the resurgence of Middle and Late Cambrian stromatolites. Strengthening the study of Cambrian microbial carbonates is conducive to further understanding the evolution process of Cambrian microbial and metazoan ecosystem.