THE DISCOVERY OF THE NANTUO DRIFT SHEET IN EASTERN HUBEI AND REDEFINITION OF THE SINIAN SYSTEM

The author and others measured two Sinian sections,the Hu’ai’ao and Liu Xinfa sections,in eastern Hubei.The predecessors considered that there is an unconformity between carbanate rocks and clastic rocks,which implies the existence of the Jinningian movement.But the present author holds that an unconformity does not exist between both.Therefore the cla- stic rocks in the lower part should belong to the lower series of the Sinian System.The author has found that the gravels and sediments in the clastic rodks have features of a glacial drift and thus are assigned to the Nantuo drift sheet.The Sinian System in eastern Hubei is divided into the upper and lower series and four formations,of which the Panjiawan and Hu’ai’ao Formations of the lower series are newly established.