烃汞叠加晕法在湖南万古金矿区及其外围深部找矿中的应用

Application of Hydrocarbon-Mercury Superimposed Halo Method in Deep Prospecting of Wangu Gold Deposit and Its Periphery in Hunan Province

为进一步验证烃汞叠加晕法在深部找矿预测中是否具有普适性,在雪峰弧形带北东段万古金矿区及其外围开展烃汞叠加晕深部找矿试验。通过分析已知矿区不同地质体、不同标高烃汞组分演化规律和矿体上部土壤烃汞综合异常结构、叠加特点及空间对应关系,指导万古金矿区外围江东矿段的深部找矿工作。研究表明:(1)万古矿区及其外围江东矿段土壤地球化学场同样存在同生叠加场和深源叠加场,同生叠加异常由于成矿物质来源于地层,Au与烃类组分相关性较差,烃汞异常呈分散状态,异常强度相对较低。(2)深源叠加异常是由于成矿物质来源于深源流体(岩浆或幔源)带来成矿物质的叠加,Au与烃汞相关性较好,烃汞异常中心突出,异常强度较强,烃类异常模式以多峰模式和对偶双峰异常模式为主。(3)烃类异常呈多峰模式出现,说明深部存在多条平行盲脉,而对偶双峰异常模式只出现头部异常峰,尾部异常峰尚未出现,说明矿体往深部延伸良好,深部找矿潜力较好。经工程验证,在江东矿段红层覆盖区取得了良好的预测效果,证实该方法具有较好的普适性。

In order to further verify whether the hydrocarbon-mercury superimposed halo method has universality in deep prospecting prediction,a hydrocarbon-mercury superimposed halo deep prospecting test was carried out in the Wangu gold mining area and its periphery in the northeast section of the Xuefeng arc.By analyzing the evolution of hydrocarbon-mercury components of different geological bodies and different elevations in the known mining areas,and the comprehensive abnormal structure,superimposition characteristics and spatial correspondence of hydrocarbon-mercury in the upper soil of the ore body,the deep prospecting in the peripheral Jiangdong ore section is guided.The results show that the soil geochemical field in the Wangu mining area and its surrounding Jiangdong mining section also has a syngenetic superimposition field and a deep source superimposition field. The syngenetic superimposition anomaly is due to the stratum,and the correlation between Au and hydrocarbon components is poor. Hydrocarbon mercury anomalies are in a dispersed state,with relatively low anomalous intensity.Deep source superposition anomaly is the superposition of ore-forming materials caused by deep source fluids(magma or mantle source),and Au has a good correlation with hydrocarbon mercury.The hydrocarbon mercury anomaly center is prominent and the anomaly intensity is strong. The hydrocarbon anomaly patterns are mainly multimodal and dual bimodal anomaly patterns.Hydrocarbon anomalies appear in multimodal patterns,indicating that there are multiple parallel blind veins in the deep,and the dual in the bimodal abnormal pattern,only the head abnormal peak appears,but the tail abnormal peak has not yet appeared. It shows that the ore body extends well to the deep indicating that the mineralization has not yet ended,and there is still a good prospecting potential in the deep part. Through engineering verification,good prediction results have been obtained in the red bed coverage area of Jiangdong ore section.It is proved that the method has good universality.