老挝沙拉坎金矿土壤地球化学特征及其意义

Soil Geochemical Characteristics and Significance of the Shalakan Gold Deposit in Laos

老挝沙拉坎金矿地处中国三江成矿带的南延琅勃拉邦岛弧带内,矿体主要赋存于石英闪长岩、砂板岩脆—韧剪切构造带中。利用研究区内土壤地球化学数据,采用传统计算法和多重分形法确定了各元素的异常范围;运用因子分析法划分出Cu-Zn-Fe-Mn-Co、Au-As-Sb、Pb-Ag元素组合以及Ni、Hg元素。结合区内地质特征,认为Au-As-Sb元素组合为金矿最佳地球化学标志元素组合。通过探槽揭露了10条金矿体群,证实了土壤地球化学测量在老挝西北地区进行地质找矿的有效性。

The Shalakan gold deposit in Laos is located in the southern Langbola island arc belt of the Sanjiang metallogenic belt in China.The ore bodies are mainly hosted in quartz diorite and sandstone brittle-ductile shear structural belt.Using the soil geochemical data in the study area,the anomaly range of each element was determined by the traditional algorithm and multifractal method.The element combina⁃tions of Cu-Zn-Fe-Mn-Co,Au-As-Sb,Pb-Ag and the elements of Ni and Hg were divided by factor analysis.Combined with the geological characteristics of the region,it is considered that the Au-As-Sb ele⁃ment combination is the best geochemical indicator element combination of gold deposits,and ten gold ore bodies are exposed through trenches,which confirms the effectiveness of soil geochemical survey for geo⁃logical prospecting in northwestern Laos.