白云凹陷断裂特征及对构造与沉积控制的作用

Feature of faults system and the influence on the tectonic and sedimentary history of Baiyun Sag

摘要:

南海北部珠江口盆地白云凹陷的地震资料分析显示，该区域自始新世以来断裂系统十分发育。断层表现出张性或张扭性特征并具有多期活动的特点。在平面上，断裂主要为NWW、近EW和 NE向。根据断层平面展布及组合形态，可将它们分为平行断层系、雁列断层系和树枝状断层系3种组合形式。根据断裂发育时间及规模，可将断裂的活动期次划分为以下几个阶段：剧烈活动期（Tg-T8）、较强-中等活动期（T8-T6）、平静稳定期（T6-T2）、再度活化期（T2-T1）。断裂发育的时间及特点对凹陷的构造演化和沉积过程起着重要的控制作用。

Abstract:

AAnalyses of the seismic data from the Baiyun Sag in the Pearl River Mouth Basin of Northern South China Sea indicate that fault systems mainly developed since the Eocene, showing tensional or transtensional features during various time intervals. Three fault groups are dominated: NWW, nearly EW and NE. Based on their lateral distribution and form, the faults could be divided into three combinations of parallel, echelon and dendritic types. These faults had played a critical role in the tectonic evolution and deposition process in the Baiyun Sag, and four stages of faulting activities can be identified: strongly active period (Tg-T8), reduced active period (T8-T6), stable period (T6-T2), and re-active period (T2-T1).