Evidence for fault activity during accumulation of the Furongian Chaomidian Formation (Shandong Province, China)

The Late Cambrian (Furongian) Chaomidian Formation accumulated in an epeiric sea that covered a large part of the North China Plate and extended from China to Korea. The depositional environment of the formation is commonly considered to have been affected by storms that broke up numerous limestone layers, but that was tectonically quiet. It is here argued, however, that some features of the formation - more in particular the many dozens of breccia layers and the occurrence of slid-down limestone blocks that are embedded in autochthonous oolites - can be explained satisfactorily only if some significant fault activity took place during its accumulation. The faulting may have been due to differential loading and subsidence, but an endogenic origin seems more probable. This implies that the structural history of the study area in Shandong Province may need re-consideration.