The Sedimentary Characteristics of the Upper Devonian Tempestite and Gravity Flow in the Ziyun Area,Guizhou and Its Geological Implications

The Upper Devonian Daihua Formation in Ziyun,Guizhou is composed mainly of carbonate rocks,in which several sets of gravity flow deposition and two sets of storm deposition were developed.The gravity flow deposition is characterized by debris flow's filling consisting of multi-phase calcarenite with matrix support,whereas the storm sedimentation by erosion structures,sag-like cross-bedding,graded bedding and drainage structure and et al.The research reveals that the gravity flow in this area resulted in three types of depositional succession association,indicating a deep-water environment,and further confirming the existence of Dianqiangui Basin within platform and trough in Devonian.Discovery of tempestite also indicates that study area should be located in the low-latitude situation near the equator during late Devonian,with warm climate and clean water.