地球化学边界(过渡带)对全球与东亚海上油气资源的制约

GEOCHEMICAL BOUNDARIES CONSTRAINT ON PETROLEUM DISTRIBUTION OF GLOBAL AND EAST ASIAN BORDER SEA

根据全球和中国大陆铅同位素填图资料表明,全球近96%的原油和90%的天然气分布于DUPAL异常和北半球参考线(NHRL)之间的过渡带(Δ8/4在20～45之间)。根据这一分布规律,全球还有大约2/3的过渡带油气资源还没有被发现和开发。海陆相连的华北克拉通地球化学边界则是中国大陆与渤海湾油气资源分布的重要制约因素。东海油气田则受华夏-扬子地球化学边界向海上和日本岛弧延伸线控制。南海油气田既位于DUPAL异常和北半球参考线(NHRL)之间的过渡带上,同时受华夏-印支地球化学边界在海上多变的走向所控制,因此具有找到大型油气田的条件。

The global mapping results of Pb isotopes show that there are transition zones between DUPAL anomaly and NHRL （north hemisphere reference line） （△8/4 =20 -45） , which control the distribution of 96% crude oil and 90% nature gas of proved reserves. Based on this distribution pattern, 2/3 petroleum resources in the world are not discovered or explorated. The North China craton margins indicated by the geochemical boundaries from continent to sea are also an important factor constraining on oil and gas distribution in North China and the Bohai Sea. The oil field of East China is located on the stretched line of the Cathysian-Yangtze geochemical boundary from Zhejiang to Japan. The oil fields in the South China Sea are located on the transition zone between DUPAL anomaly and NHRL, and also controlled by the changeable geochemical boundaries between the Cathysian and Idochina blocks from continent to ocean. Thus there are potential for finding large oil fields in the South China Sea.