重磁方法在吐尔库班套铜镍矿区勘查中的应用

利用实测的重、磁资料和岩石物性资料,并结合矿区地质、钻孔等资料,确定了重高、磁高为吐尔库班套铜镍矿区内识别超基性和基性岩体的标志,重磁对应分析结果表明研究区重磁异常具有很好的同源性。利用归一化总水平导数垂向导数( NVDR_THDR)技术推断了5条断裂,研究认为北西向断裂形成较早,其与研究区主体构造走向一致,北东向断裂形成较晚并将北西向断裂错断。利用布格重力异常垂向二阶导数、化极磁力异常垂向一阶导数以及重磁对应分析结果推断了18个基性、超基性岩体并研究了其规模及平面分布特征,利用重磁联合人机交互反演技术解释了基性、超基性岩体的纵向分布特征和规模,结果表明研究区基性、超基性岩体规模不大。综合研究了断裂分布特征以及岩体分布特征,认为研究区基性、超基性岩体的分布明显受断裂控制,而且主要分布在F1、F4和F5断裂组成的区域,并具有明显的分带性,其与北西西向的断裂分布是一致的,推测岩体主要沿着北西西向断裂侵入,北东向断裂对岩体的分布起到限制作用。

The application of gravity and magnetic techniques to the prospecting for the Tuerkubantao copper-nickel ore district

On the basis of observed gravity and magnetic data combined with geological information and borehole data obtained in the Tuerkubantao Cu-Ni ore district,the authors determined high gravity anomalies along with high magnetic anomalies as symbols to recog-nize ultrabasic rocks and basic rocks in this area. The authors used the correlation analytical method to analyze gravity and magnetic a-nomalies and,through computation of the correlation coefficient of gravity and magnetic anomalies,found that they are obviously of con-sanguinity. The authors deduced five faults with the edge recognition technology based on the normalized vertical derivative of the total horizontal derivative( NVDT_THDR) for potential field data. It is shown that the NWW-SEE trending faults were formed earlier and they are in accord with regional structure trend. The NE-SW trending faults were formed later and disconnected the NWW-SEE tren-ding faults. 18 ultrabasic rocks and basic rocks were recognized based on the second order vertical derivative of Bouguer gravity anoma-lies,the first order vertical derivative of magnetic anomalies reduced to the pole and the result of correlation analysis. Then a discussion was made on the plane distribution characteristics and the size of these rocks. Their vertical distribution characteristics and size were al-so studied by using the gravity and magnetic man-computer interactive joint inversion method. The results indicate that the sizes of the ultrabasic rocks and basic rocks are not big. In consideration of both the characteristics of the faults and the rocks,the authors hold that distribution of the rocks is controlled by faults. The ultrabasic rocks and basic rocks are mainly distributed in the area surrounded by F1 fault,F4 fault and F5 fault. The distribution of the rocks can be divided into three stripes which coincide with the NWW-SEE trending faults. It is thought that the rocks intruded along the NWW-SEE trending faults and were constrained by NE-SW trending faults.