陕西秦岭巴山地区化探异常查证找矿实例分析

在陕西秦岭巴山地区9万km²内,通过1:20万区域化探扫面,发现了一批多元素综合异常,并根据地质构造背景分析划分出五个异常带(区)。其中新发现的北秦岭Au、Ag、Pb、Zn异常带,规模大、元素组合复杂且含量高,为一重要的金、多金属成矿带。1986年开始,在该区大力开展区域化探异常查证工作。通过1:5万水系沉积物测量,圈定了以金元素为主的化探异常。在主体异常部位系统地开展了1:1万土壤测量和槽探工程,于当年就在周至县马鞍桥发现了金矿体。随后又根据化探异常特征,布置了钻探和坑探工程验证。经进一步检查和详查,确认马鞍桥金矿为一大型金矿床。

EXAMPLES OF GEOCHEMICAL ANOMALY INSPECTION AND ORE PROSPECTING IN BASHAN AREA, QINLING MOUNTAINS,SHANXI PROVINCE

Within 90 000 km² of Bashan area, Qinling Mountains, Shanxi Province, the 1:200000 regional geochemical survey led to the discovery of quite a few multi element composite anomalies, which were then divided into five anomalous zones (districts) on the basis of geologic tectonic analysis. Among these anomalous zones, the newly discovered North Qinling Au, Ag, Pb, Zn anomalous zone is an important gold and polymetallic ore belt characterized by large size, complicated element combination and high element content. Since 1980, extensive regional geochemical anomaly inspection work was carried out in this district. Through 1:50000 stream sediment survey, geochemical anomalies dominated by Au were delineated. At the position of the principal anomaly, 1:10000 soil survey and trenching exposure were systematically conducted and, as a result, gold orebodies were discovered at Maanqiao of Zhouzhi County. Afterwards, drilling and pit prospecting rerification work was arranged. Further inspection and detailed investigation proved the Maanqiao gold deposit to be a large size gold deposit.