基于地球物理重磁特征的扬子古陆与华夏陆块边界划分

Boundary division of Yangtze ancient land and Cathaysia land block in the Guangxi section based on geophysical gravity and magnetic feature

扬子古陆与华夏陆块广西段的具体分界一直存在争议,利用广西1∶20万重磁异常对扬子古陆与华夏陆块广西段的分界进行探讨。利用布格重力异常、航磁ΔT异常以及小波多尺度分析、窗口滑动平均等方法分离的重磁异常,并进行重磁场分区,分析分界的深部构造展布特征,对扬子古陆与华夏陆块广西段在四堡期和早古生代的分界进行划分,提出了边界划分新的认识。划分分界的重磁场线性特征清晰、明显,重磁场依据充分,为扬子古陆与华夏陆块广西段分界以及基础地质研究提供了重要的地球物理依据。

The specific boundary between Yangtze ancient land and Cathaysian land block in the Guangxi section has always been controversial.In this paper,the boundary between Yangtze ancient land and Cathaysian land block in the Guangxi section is discussed by using the 1∶200,000 gravity and magnetic anomaly.Bouguer gravity anomaly,aeromagneticΔT anomaly,wavelet multi-scale analysis and window moving average and other methods are used to separate the gravity and magnetic anomalies.The division of gravity and magnetic fields is also carried out.The deep structural distribution characteristics of the boundary is analyzed.The boundary between Yangtze ancient land and Cathaysian land block in the Guangxi section of the Sibaoian and early Paleozoic periods is divided.A new understanding of the boundary division is put forward.The linear feature of gravity and magnetic fields is clear and obvious,and the basis of gravity and magnetic fields is sufficient.It provides an important geophysical basis for the boundary between Yangtze ancient land and Cathaysian land block in the Guangxi section and the basic geological research.