ON OIL AND GAS PROSPECTS OF DABA AREA

The author of this paper studies the tectonic evolution of Qingling-Daba Region and the organie geochemical characteristics of the source rocks in the area.More detail analysis have been made on the evolutionary regularities of the source rocks during the time of the tectonic development. It comes to the following conclusions. 1.The auiacogen there is a typical paleozoic protobasin developed from Sinian to Triassic time. The evolution of the basin can be devided into three stages and subdevided into six episodes.The source rocks developed mainly from Cambrian to Silurian (the most active growing period of the aulacogen) are claystones and carbonate rocks with a large thickness, high organic content,excellent kerogen type and high oil/gas generating potential. Although the organic matter is locally overmature, it is considered that the southern flank of the aulacogen and the adjacent part of Yangtze Platform are the favourable area for oil/gas exploration 2.The southern Shaanxi-northeastern Sichuan overthrust system is a major system. Its history of development and formation can be devided into 4 stages and the main stage is from Late Yenshanian to Himalayan time. It is believed that such a overthrust system is a significant frontier for oil/gas exploration.