Early Cambrian Reefs on the Northern Margin of the Sichuan Basin

摘要

The early Cambrian reefs, along the northern margin of the1 Sichuan Basin, stretches for about 320 km. Hermavupie fossils are archaeocyathus, algae and stromatolites. Two strata containing reefs are Xinnnudong Formation and Tianheban Formation (or Kongmingdong Formation). There are 8-10 reefs hearing layers in Xiannudng Formation and 1-5 reefs bearing layers in Tianheban Formation (or Kongmingdong Formation). Most archaeocyatha-algae-algae reefs located in low energy zone of subtidal, few reefs located in the high energy zone of subtidal. Transportation of reefs is affected by the changes of sea leval. Live struggle for existence in the reefs was very intense.