ON THE MECHANISM AND THE CHARACTERISTICS OF EARLY CAMBRIAN“STONE COAL”IN LOWER YANGTZE REGION AND THEIR RELATION TO PETROLIFEROUS POTENTIALS

Through Cambrian geohistory of Lower Yangtze area,only at the beginning of early Cambrian could"stone coal"be formed and wide spreaded throughout the area.The stone coal was the result of synsedimentation of fungous algal organic remains and gel siliceous deposits.The conditions of its formation are dominated by the following three decisive factors 1.abundance of fungous-algae;2.palaeogeographic location-the slope section of basins with anoxic viscous flow;3.the sedimentation(the condition of burial history)."Stone coal" contains abundant organic matter,with organic compositions of 50-55%.The environments of anoxic viscous flow basin in which "stone coal" formed is the most favourable to oil generation.Thus the "stone coal" is considered as major source series and oil and gas have been generated and migrated during its geological history.