应用奇异值分解技术提取滇东南锡-钨多金属矿化航磁异常

滇东南锡-钨多金属矿集区位于扬子陆块、华夏陆块及印支陆块的交汇处，区内分布一系列与晚白垩世大规模岩浆作用密切相关的锡、钨、铜、银、铅、锌多金属矿床。对滇东南1：200 000航磁数据化极处理后，应用奇异值分解（SVD）技术提取航磁数据中与锡-钨多金属矿化有关的深部地质结构和地质体特征分量。通过定义不同的滤波器，选择相应的特征分量进行重构，获得反映深部及浅层的地质结构和地质体空间分布的图像。研究表明：①研究区深部存在2种磁性特征的基底，即强磁性基底（哀牢山岩群、大红山岩群和瑶山岩群）和弱磁性基底（昆阳群和猛硐岩群）；②与矿化密切相关的花岗岩体显示为环绕负磁异常发育正磁异常，环形正磁异常可能反映了接触交代矿化蚀变带的空间分布；③环绕负磁异常发育正磁异常区域是进一步找寻锡-钨多金属矿床的最佳靶区。

Singular Value Decomposition(SVD) used to extract aero-magnetic anomalies related to Sn-W polymetallic mineralization in SE Yunnan,China

The Sn-W polymetallic ore-concentrated area in SE Yunnan is located at the junction of the Cathaysian Massif, Yangtze Massif, and Indo-China Massif, where there are a series of Sn, W, Cu, Ag, Pb, Zn polymetallic deposits closely related to the Late Cretaceous magmatism.The Singular Value Decomposition(SVD) was applied to extract aero-magnetic anomaly components reflecting the deep geological structures and geological bodies associated with the Sn-W polymetallic deposits and mineralized granitic intrusives from the aero-magnetic data of the SE Yunnan district at a scale of 1:200 000.The results show that there are two metamorphic basements, one with strong magnetism(Dahongshan Group, Ailaoshan Group and Yaoshan Group), and the other with weak magnetism(Mengdong Group); granitoids closely related to W-Sn polymetallic mineralization in the study area shows a ring positive magnetic anomaly around a negative magnetic anomaly, which may reflect a contact skarnization zone around a granitic intrusion; and the ring positive magnetic anomalies around negative magnetic anomaly are the best targets for further exploration of Sn-W polymetallic deposits.