珠江三角洲地区重磁资料解释的深部断裂及其新构造意义  

DEEP FAULTS INTERPRETED BY GRAVITY-MAGNETIC DATA IN THE PEARL RIVER DELTA REGION AND THEIR NEOTECTONIC SIGNIFICANCE

作　　者：任镇寰[1] 叶秀薇[1] 黄剑涛[1] 廖桂金[1] 孙崇赤[1] 刘天佑[2] 乔计花[2] 魏伟[2] 

机构地区：[1]广东省地震局,广州510070 [2]中国地质大学,武汉430074

出　　处：《第四纪研究》2009年第3期625-632,共8页Quaternary Sciences

基　　金：广东省自然科学重点项目(批准号:2003C326002)资助

摘　　要：对珠江三角洲地区布格重力和航磁资料系统处理、研究、解释,确认珠江三角洲地区地壳深部存在近EW向、NW向和NE向3组断裂系统。近EW向断裂是深部主要断裂系统,大部分断裂深及30km以上,其中有些断裂是以往很少为人们关注的;NW向断裂分布也比较广泛,但深度相对较浅,大都在10km左右,不超过20km;NE向断裂虽然地表出露最广,规模最大,但只有广州-恩平断裂可深及30km以上,大多数也相对较浅,特别是以往一些被称为深大断裂的断裂只有10km左右深度,不超过20km。上述工作新成果同传统概念的珠江三角洲地区深大断裂格局有较大改变。本文提出"新构造期深大断裂"的新概念及理论分析、解释这种格局的改变。并认为它对研究新构造、地质构造、工程地质、地震地质、找矿、找水、地质灾害等方面或具有科学理论意义和实用价值。文章还阐述了近EW,NW和NE向3组断裂间的相互切割关系,认为前二组断裂活动较NE向断裂更活跃或更新一些。Based on processing, analyzing, and interpreting the Bouguer gravity and aeromagnetic data,it is confirmed that there were three fault systems, the EW, the NW, and the NE in the crustal deep level of the Pearl River Delta region. The EW one is the main fault system in deep level,with the depth of the most part over 30km. According to this interpretation, the depth of the Fogang- Heyuan Fault （EW）was only about 10km, although it was formerly considered as an abyssal fault. The NW faults were distributed in a wider area,with the depth shallower than 20km, mostly about 10km. The outcrop of the NE faults is the most widely seen among these three fault systems. However,the NE faults,besides the Guangzhou- Enping Fault whose depth is over 30km, are relatively shallower, especially those previously considered as abyssal faults, such as the Heyuan -Zhongshan （Shaowu）Fault, the Huidong- Shenzhen（Lianghuashan） Fault which are about 10km and less than 20km in depth. These results differ largely from the traditional ideas on the abyssal fault pattern in Pearl River Delta region. We thus propose a new concept the Neotectonic Stage Abyssal Fault. According to this concept, all tectonic movements have their sources in the deep. Every tectonic movement had rearmed（ sometimes even thoroughly reformed）the deep material composition and the structure pattern. All these should have been recorded in gravity and magnetic fields. This new concept might be applied to the some research fields, e. g., neotectonics, seismologeology, geological structure, geological hazard, and mineral and water resources. We also discussed the dissecting relationships among the three fault systems. The EW fault system dissected the other two more markedly. Then came the NW fault system and the NE fault system is the weakest.

关 键 词：重磁资料 深部断裂系统 新构造运动 珠江三角洲地区 

分 类 号：P631.2[天文地球—地质矿产勘探] P546[天文地球—地质学]