THE SINIAN SEDIMENTARY FACIES AND STRATIGRAPHIC SEQUENCE ANALYSIS,DONGZHI,SOUTH ANHUI
Wu Yuedong (Anhui Regional Geological Survey)
The Sinian system was completely developed and well exposed in a wide area of Dongzhi, South Anhui.It is the oldest cover in the Jiangnan-type stratigraphic area with of sedimentary types and so many kinds of rocks as an important depositional strata-bound mineral host of rich of rich iron , mangnese, phosphorus, gold,etc.Study shows a terrestrial-source clastic sedimentaty setting dominant in the early period of the early Sinian as a reflection of marine progression and a glaciation in the late leading to from coast-glacial facies to shelf-glacial facies deposition as of regression.The Sinian may be divided into two Ⅰ type stratigraphic sequences.The first one is for the early period of Early Sinian composed of low Water level system domain progressive system domain and contractional section . The high water level system domain was lost due to the intense truncating on the underlying strata by glaciation.The second one is a complete Ⅰ type sequence from the late period of Early Sinian to the late of late Sinian.
【CateGory Index】： P534