安徽省杨坑口地区土壤地球化学特征及找矿意义

Soil Geochemical Characteristics and Prospecting Significance in Yangkenkou Area,Anhui Province

安徽省石台县杨坑口地区位于长江中下游成矿带的南外带。通过在该研究区开展 1∶10000 土壤地球化学测量,进行元素空间分布特征及地球化学异常特征分析。结合研究区地层、构造、岩浆岩等地质特征,圈定了Pb异常4处,Zn异常3处,Ag异常3处,Au异常3处,Cu异常4处,Mo异常2处,Bi异常8处。据此在研究区一带进一步圈定了AP1 #以Pb、Zn、Cu、Mo、Ag为主的异常带及AP2 #以Au、Bi、Cu、Zn、Mo为主的异常带。针对土壤地球化学异常套合地段进行了槽探工程验证,分析了异常物质来源。研究表明:①研究区断裂构造发育,断裂带内褐铁矿化、硅化等蚀变发育明显,在异常带内发现了铅银矿化体;②石台地区位于下扬子地层分区与江南地层分区的过渡带,岩浆活动频繁,研究区北部谭山岩体为成矿岩体,其蚀变现象明显,有热接触变质作用和热液蚀变作用引起的蚀变和明显的金属矿化显示,具有较好的找矿前景。

The Yangkenkou area in Shitai County of Anhui Province is located in the south outer zone of the middle and lower reaches of the Yangtze River metallogenic belt.Through conducting 1 ∶ 10 000 soil geochemical survey work in the study area,so as to analyze the element spatial distribution characteristics and characteristics of geochemical anomalies.Combing with the geological characteristics of strata,structures and magmatic rocks in the study area,four Pb anomalies,three Zn anomalies,three Ag anomalies,three Au anomalies,four Cu anomalies,two Mo anomalies and eight Bi anomalies are delineated.Based on the anomalies delineated results,the AP1 # abnormal zone mainly for Pb,Zn,Cu,Mo and Ag and AP2 # abnormal zone mainly for Au,Bi,Cu,Zn and Mo are determined in the study area.In view of the soil geochemical anomaly nesting ares,trench engineering verification work is done,the material source of anomalies are discussed.The study results show that:①the fault structure in the study area is well developed,the alterations such as limonitization and silicification are obviously developed,lead-silver mineralized body is found in abnormal zone;②Shitai area is distributed in transition zone between the Lower Yangtze stratigraphic zone and Jiangnan stratigraphic zone,the magmatic activities are very frequent,Tanshan rock mass in the north of study area is belongs to metallogenic rock mass,its alteration phenomenon is obvious. The alteration caused by thermal contact metamorphism and hydrothermal alteration and obvious metallic mineralization show that the prospecting prospect of the study area is good.