东海陆架盆地南部及邻区陆域中生界对比

CORRELATION OF THE MESOZOIC BETWEEN SOUTHERN EAST CHINA SEA SHELF BASIN AND ITS ADJACENT AREAS

为了探讨东海陆架盆地南部中生界油气勘探前景,在对现有的钻井资料、地震剖面和重磁资料处理的基础上,对东海陆架盆地南部及邻区陆域的中生界岩相组合和地层展布特征进行分析对比。综合研究认为:陆域中生界分布广,但发育不均,沉积类型多样,火山活动频繁;海域中生界分布广、厚度大,呈现"东厚西薄、南厚北薄"的特征。海陆中生界的差异主要表现在:陆域中生界受火山活动影响较大,以陆相火山岩沉积为主,而海域中生界受火山活动影响相对较小,主要为受海侵影响的湖相沉积。因此,由陆到海,中生界岩性变细、颜色变暗,海域的生烃潜力可能优于陆域。

In order to further understand the distribution pattern of the Mesozoic strata in the southern East China Sea Shelf Basin, this paper deals with the lithofacies assemblages and stratigraphic distri- bution in the southern East China Sea Shelf Basin and its adjacent areas, upon the geological and geo- physical data recently aequired from seismic survey, drilling, gravity-magnetic survey and field obser- vations. The results suggest that the Mesozoic strata in the adjacent areas of the basin are widely dis- tributed and characterized by heterogeneous sedimentary sequences and strong volcanic activities, whereas the Mesozoic strata in the basin eover an extensive area with a targe thickness over 6000 m, which is thick in the south and east, but thin in the north and west＇. There are obvious differences be- tween the land and the sea： the land is more affected by volcanic activities and dominated by continen- tal volcanic deposits, while the sea area is less affected by volcanic activities and dominated by lacus- trine deposits under the influence of marine transgression. The sediments become finer and darker in the basin. Therefore, the sea area is more favorable for hydrocarbon exploration.