EARLY ORDOVICIAN LITHOFACIES AND PALEOGEOGRAPHY IN EAST NORTH CHINA PLATFORM

The paper shows that obvious change takes place in north-south Ordovician depo- sits is North Chias Platform.Its south part rose during Yeli Age, and sea water wi- thdrew from north to south.The sediments of Yehli Formation is not Iound is a zone betweea Mouat Song and Yu Couaty but occurs is Fengfeng. Further towards north, they are well developed.Therefore, from Fengfeng to West Beijing forms a slope with its gradient of 1，5000, its south is high,north low.Dolomite facies dec- reases from south to north till vanish, whereas micrite increases from south to north. Organic fossil is from nothing to appearance and again from abundance to decrease from Mount Song to West Beijing