摘要
广从断裂带在金沙洲段以3条近平行的北东向分支断裂展布,钻孔岩芯及显微构造分析表明,研究区基岩受断裂活动影响无疑,且断裂活动时代较新。以金沙洲基岩之上普遍存在的土黄色-褐黄色粉砂质黏土(或黏土)标志层为样品进行粒度分析,所得粒度参数及概率累积曲线表明,该层沉积物可与珠江三角洲其他区域进行对比,为晚更新世晚期(10~20 ka B.P.)沉积,该地层之上灰黑色-黑色淤泥质层(或细砂层)出现了明显的全新世高海面沉积异常,淤泥层中腐木的^(14)C年龄为6~7 ka B.P.,确认广从断裂金沙洲段的最新活动年龄为6~7 ka B.P.。
The Guangzhou-Conghua Fault is located in Jinshazhou area in the form of 3 sub-parallel NE-trending branching faults.Drill cores and microstructure analysis show there has been a relatively new tectonic compression on its bedrock. This paper sampled the maker bed of widespread wheat-isabelline silty clay（ or clay） on the bedrock to analysis its particle size. The result of particle parameters and cumulative probability curve show that the layer of sediment can be compared with that of other regions in the Pearl River Delta,and it is Late Pleistocene（ 10-20 ka B.P.） deposition. The ash black-black silty bed（ or fine sand layer） on the maker bed shows a clear Holocene thalassocratic abnormal deposition,and ^14C dating of the rotten wood in the silt layer is 6-7 ka B. P.. Thus,it is concluded that latest activity time of the Jinshazhou segment in the Guangzhou-Conghua Fault is about 6-7 ka B. P..
作者
陈小月
Chen Xiaoyue(Guangzhou Geological Survey Institute,Guangzhou 510440,Guangdong,China)
出处
《地质学刊》
CAS
2018年第2期222-227,共6页
Journal of Geology
基金
广州市财政专项资金项目"广州城市地质环境监测预警新技术示范研究"([2009]01)
关键词
广从断裂带
金沙洲段
14C年龄
全新世断裂
广东
Guangzhou-Conghua Fault
Jinshazhou segment
C dating
Holocene fault
Guangdong
