Transgressive deposits from the Luoquan Formation in Shuiyu,Ruicheng,Shanxi

The Luoquan Formation and its equivalents on the southern and southwestern margins of the North China landmass have long been interpreted as the latest Neoproterozoic glaciogenic deposits.In the Shuiyu region,Ruicheng,Shanxi,the Luoquan Formation shows a horizontal dramatic change due to the controls of the erosional surface of the underlying strata,and only consists of a succession of extraordinary "gravel-bearing sandy oolitic dolostones" containing parautochthonous gravels and intraclastics.Viewed from lithology,sedimentary textures and structures,and sedimentary facies,the authors in the present paper argue that the "oolitic dolostones" in the Luoquan Formation should be originated from the coastal tractional currents under the conditions of warm climates rather than from the glaciation.The first report of the "oolitic dolostones" has important implications for the recognition of the sedimentary environments of the Luoquan Formation.