摘要
南海北部陆缘发育大量含油气盆地,且南海北部陆坡存在丰富的天然气水合物资源,厘清其总体构造格局,对理解南海北部陆缘的构造演化及动力学机制、地震灾害评估与资源开发等具有十分重要的意义。本文通过重磁异常、二维地震资料解译,结合地震活动及构造地貌特征分析,发现华南陆块和南海北部陆缘的NE向主干断裂延伸方向一致且特征可进行对比,即华南发育的滨海、长乐-南澳、政和-大埔及邵武-河源-阳江四条NE向主干断裂可自然延伸至南海北部陆缘。延伸至南海北部的四条主干断裂控制了相应盆地的发育,其中,滨海断裂为珠二凹陷的东界,长乐-南澳断裂横穿珠江口盆地的珠一和珠二凹陷,政和-大埔断裂位于珠一、珠二坳陷的西界以及北礁凹陷的东界,河源-阳江断裂为琼东南盆地的西界。南海北部陆缘盆地群与华南陆缘盆地群在成因上具有相似性,皆为拉分盆地。南海北部陆缘分布的NE向右行断裂对盆地的发育以及展布起决定性作用,为控盆断裂。NEE向断裂控制盆地内部坳陷的充填样式,为控坳断裂。
The northern continental margin of the South China Sea hosts numerous oil- and gas-bearing basins, the northern South China Sea Continental Slope, in particular, is characterized by enrichment of gas hydrate. Detailed investigations into the propagation of NE-trending faults in South China to the northern continental margin of the South China Sea and the clarification of the overall structural pattern have a very important significance for understanding the earthquakes, resource exploration, tectonic evolution and dynamics in the northern South China Sea. Based on the interpretation of gravity and magnetic anomalies, two-dimensional seismic profiles as well as earthquake activity and tectonomorphological analysis, we find that the structural characteristics of the major NE-trending faults in the South China Sea and the South China Block are similar, the four major faults, namely the Binhai Fault, the Changle-Nan＇ao Fault, the Zhenghe-Dabu Fault and the Shaowu-Heyuan-Yangjiang Fault developed in the South China Block and extended into the northern South China Sea. The four main faults that extend to the northern South China Sea controlled the development of the basins, i.e., the Binhai Fault is the eastern boundary of the Zhu＇er Depression; the Changle-Nan＇ao Fault across the Zhujiangkou Basin; the Zhenghe-Dabu Fault is located at the western boundary of the Zhuyi and Zhu＇er depressions and the eastern boundary of the Beijiao Depression, the Shaowu-Heyuan-Yangjiang Fault is the western boundary of the Qiongdongnan Basin. These basins in the South China Block and the northern South China Sea are similar in formation regime as pull-apart basins. The NE-trending dextral strike-slip faults in the northern continental margin of the South China Sea controlled the development of these basins, and the NEE-trending faults controlled the filling pattern of the depressions.
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2014年第3期557-570,共14页
Geotectonica et Metallogenia
基金
国家自然科学基金项目(批准号:41325009
41190072)
中央高校基本科研业务费中国海洋大学专项基金项目(编号:2011-12)资助
关键词
华南陆块
南海北部
大陆边缘
NE向断裂
延伸
South China Block
northern South China Sea
continental margin
NE-trending faults
propagation
