EARLY CARBONIFEROUS SEQUENCE STRATIGRAPHY AND SEA-LEVEL CHANGES IN THE NINGZHEN MOUNTAIN AREA NEAR NANJING,JIANGSU

This paper focuses on the Early Carboniferous sequence stratigraphy of the Ningzhen mountain area.Based on sedimentary facies and ecological analysis,five sequences equivalent to the third-order cycles are recognized in the Wutong,Jinling,Gaolishan,Hezhou and Laohudong Formations in the study area.Two major drops corresponding to the supersequence boundary are also identified in the Lower Carboniferous,one occurs at the boundary between the Jinling and Gaolishan Formations;another appears at the uppermost of the Laohudong Formation.Moreover,the Early Carboniferous sea-level curve for the Lower Yangtze Sea has been reconstructed by the authors according to the above-mentioned sequence stratigraphic analysis for the Nanjing region.This curve is different from the synchronous eustatic curve by Ross and Ross (1987) because of the specific palaeogeographic position of the study area.