基于特征分析法的琼南矽卡岩型矿床成矿预测研究

Metallogenic Prognosis for Skarn-type Deposits Based on Characteristic Analysis in Southern Hainan Island

在系统总结琼南矽卡岩型矿床区域成矿地质背景与成矿规律的基础上,分析和提取了地质、物探、化探、重砂、遥感等多元有利找矿信息,具体包括碳酸盐岩地层、燕山晚期中酸性侵入岩、控矿断裂、航磁推断磁性蚀变带、化探Cu、Pb、Zn、Au、Ag单元素异常及Cu-W-Mo、Pb-Zn、Au-Ag组合元素异常、自然重砂Fe、Pb-Zn异常以及遥感羟基和铁染蚀变异常等。并利用上述找矿信息及6个模型控制单元(即已知含矿单元)建立了特征分析初始矿化模型M1,同时为解决模型M1中控制单元不足的问题,我们从中筛选了联系度f≥4的26个单元作为新的模型控制单元,重新建立了广义矿化模型M2,并据此圈定了4个A级、2个B和2个C级矽卡岩型矿床找矿预测靶区,为本区矽卡岩型矿床的找寻提供了重要的科学依据。

The study area, covering an area of 4000 km2, is located in southern Hainan island. In this area, the carbonate and intermediate-acid intrusions are widely distributed, so it＇s conducive to formation of skarn-type deposits. In this paper, multisource data sets were integrated for mineral potential mapping using GIS technology. Based on systematical analysis of the regional geological background and metallogeny of the skarn-type deposits, 19 favorable predictor variables including the Late Yanshanian intermediate-acid intrusive rocks, ore-control faults, geological bodies inferred by aeromagnetic anomalies, geological exploration anomalies of Cu, Pb, Zn, Au, Ag, Cu-W-Mo, Pb-Zn, Au-Ag, heavy mineral anomalies of Fe, Pb-Zn and alteration information of remote sensing were extracted. Furthermore, by combining these predictor variables and 6 known ore-bearing units, we established an initial characteristic analysis model M1, and in order to resolve the lack of model control units, we also proposed a generalized model M2 using 26 new units which were selected from model M1 by degree of match for cells. Finally, on the basis of the model M2, we delineated 4 A-, 2 B- and 2 C-level prospecting areas which will surely contribute to the prospecting for skarn-type deposits in this region.