甘肃文县阳山金矿床葛条湾-安坝矿段原生晕地球化学特征及深部找矿远景评价

甘肃文县阳山金矿是产于勉略缝合带内的超大型卡林-类卡林型金矿床。为探讨矿区深部找矿潜力和成矿远景评价,文章对葛条湾-安坝矿段30号勘探线剖面的成矿及伴生元素原生晕地球化学特征进行研究,结果表明:该矿段原生晕的轴(垂)向分带序列自上而下为:Pb—Co—Cu—Zn—Mn—Bi—Mo—Sb—Au—As—Ag。矿体中部原生晕具有反向分带特征,原生晕出现前缘晕、尾晕叠加,显示具有多阶段热液叠加成矿作用的特征。在深部1400 m标高,前缘晕并未消失,并向深部强度增大,尾晕仅为弱异常。同时,原生晕地球化学参数(As×Sb)/(Mo×Bi)、(As+Sb)/(Mo+Bi)比值发生转折并升高,前缘晕因子得分在深部有很强的高值异常,进一步证实深部具有盲矿体存在的可能性。综上表明,阳山金矿矿区深部找矿前景较好。

Geochemical characteristics of primary halo and evaluation of deep mineralization prospect of Yangshan gold deposit, Wenxian, Gansu Province

The Yanshan gold deposit located along the Mian-Lue suture belt in the west of Qinling orogenic belt is a superlarge Carlin-Carlin-like deposit. This paper systematically analyzes the geochemical characteristics of primary halo of metallogenic and accompanying elements from the No. 30 exploration line section in Getiaowan-Anba ore block. This study exhibits a series of Pb-Co-Cu-Zn-Mn-Bi-Mo-Sb-Au-As-Ag in axial zonation sequence. And the primary halo in the middle of the orebody shows reverse zonation that the top and the tail of the primary halo coexist, which was probably caused by multiple phases of hydrothermal superposed mineralization. At the depth of 1400 m, the front halo does not disappear and becomes more strong toward the depth, but the tail halo shows weak anomaly. The geochemical parameters of (As×Sb)/(Mo×Bi),(As+Sb)/(Mo+Bi) are increasing in reverse, and factor score of the front halo shows quite strong high value area. These features suggest the presence of a blind orebody and prospecting potential in the deep area.