潮汕坳陷被认为是一个具有良好油气前景的中生代残留沉积坳陷,其中生代地层也被新近的钻井证实。为研究其盆地深部构造.“十五”863课题跨越该区进行了深地质调查。调查采用5台国产海底地震仪记录深部地震资料。处理结果显示本次调查清楚地记录到了来自地壳内部和Moho面的震相,这是国产海底地震仪在南海地区的首次成功实践。海底地震仪记录揭示沿测线的地壳在南海形成过程中减薄程度较低,中生代地层速度较高,代表致密的岩石,这些因素可能不利于油气的储集,需要在勘探中避开。
Chaoshan Sag has been regarded as a prospective relic Mesozoic sedimentary sag in the South China Sea. Recent drilling confirms the existence of the Mesozoic group. In one field experiment, five sets of ocean-bot- tom seismometers assembled by Chinese scientists have been deployed successfully to explore the deep geological structure of the basin. The ocean-bottom seismic data show clear phases from inner crust and Moho discontinuity. The data also reveal that the crust over the Chaoshan Sag thins less compared with the neighboring areas in the northern South China Sea, and the seismic velocity of the Mesozoic formation increases considerably, which im- plies high consolidation of sedimentary rocks, not prone to petroleum accumulation. Such case should be avoided in future exploration of petroleum.