【摘要】 莺-琼盆地(即莺歌海盆地和琼东南盆地)位于印支地块与华南大陆交汇处,该区域地质构造复杂,为南海西北走滑型和伸展型陆缘的交汇区,也是印澳-欧亚板块碰撞"挤出-逃逸构造区"和"古南海俯冲-拖曳构造区".莺-琼盆地的北部以红河断裂带中1号断裂为界,前人对其认识比较统一,但莺-琼盆地南部由于地质和地球物理资料较少、研究程度低,以致其构造格局及分界位置不明确.通过对重、磁资料的处理,认为在莺-琼盆地分界的北段存在明显的重力异常和磁力异常梯级带,该梯级带与1号断裂位置相对应;在其南段存在明显的重力异常和磁力异常高值带,推断该高值带为一"中建凸起",结合重、磁对应分析技术确定了该"中建凸起"的分布范围.采用重、磁异常归一化总水平导数垂向导数技术识别出控制莺-琼盆地分界两侧的断裂构造,在分界以西断裂走向主要为北北西向,分界以东主要为北东向.通过地质和地球物理综合研究认为莺-琼盆地的北段以1号断裂为界,南段以"中建凸起"为界.更多还原

【Abstract】 Ying-Qiong basin(Yinggehai basin & Qiongdongnan basin)locates in the position-joint of Indosinian Block and South China Continent.With complex geological structure,the region is at the confluence of strike-slip and extensional continental margins in the northwestern of the South China sea,and it’s also the extrusion-escape tectonic area of India-Australian and Eurasian plate collision,and the subduction-stretch tectonic zone of Paleo-South China sea.It is universally acknowledged that No.1 fault is the northern boundary of Ying-Qiong basin.However due to the lack of geological and geophysical data in the southern part,the tectonic framework in this area and the location of the southern tectonic boundary of Ying-Qiong basin are not explicit.By processing the gravity and magnetic data,we realize that there is an obvious gravity and magnetic anomaly belt to the north of the boundary of Ying-Qiong basin,and the belt is just in the position of No.1 fault.There is an obvious zone with higher value of gravity and magnetic anomaly,which we deduced "Zhongjian rise".And using the technology based on correspondence analysis of gravity and magnetic anomalies,we ascertained the range of the rise.We recognized the faults near the boundary of Ying-Qiong basin using the technology based on the normalized vertical derivative of the total horizontal derivative(NVDR_THDR) for gravity and magnetic anomaly data.NNW-trending faults are primarily distributed in its west,and NE-trending in the east.With the comprehensive research on geological and geophysical data,we conclude that the northern boundary of Ying-Qiong basin is the No.1 fault,"Zhongjian rise" is the southern boundary.更多还原