Taking the Upper Permian Dalong-Longtan Formations and the Lower Triassic Qinglong Formation in the southern part of South Yellow Sea as examples

it is discusses exploration and appraisal methods of this remnant marine basin. According to analysis

the residual basin was formed during Indosinian and early Yanshanian. It was composed of a series of thrusted anticline-horst zones and was connected with the Nanjing-Anfeng ramp zone. It experienced three evolutionary stages

including craton formation

compressional thrusting and chasmic strike slipping

which resulted in two hydrocarbon generation modes

with Dalong-Longtan Formations and Qinglong Formation to be the source rocks

respectively. The former has been deeply buried and accompanied by hydrocarbon generation just for one time

just like those in Wunansha uplift

where the buried hill oil and gas reservoirs would be the main exploration targets. The latter has been deeply buried twice and each to be accompanied by hydrocarbon generation

just as those in the southern downwarping region

where several marine and continental petroleum systems and oil and gas accumulations might have been developed.