地球化学原生晕对鄂东南石头咀铜铁矿床外围找矿方向的指示

Indication of Geochemical Primary Halo on Prospecting Direction of Periphery of Shitouzui Copper Iron Deposit in Southeastern Hubei Province

鄂东南石头咀铜铁矿床的矿体赋存于三叠系碳酸盐岩与石英闪长岩接触带部位,矿体走向NW,倾向NE,产状较陡,其深部矿体呈“台阶状”分布,并具有局部膨缩、尖灭再现等特征。在矿体中心部位,矿石以铜铁矿石为主,向南东逐渐过渡为铜矿石。矿体三维原生晕异常显示,Cu、Au等成矿指示元素的浓集中心与钻孔实际揭露的矿体空间位置基本一致,As、Sb等前缘指示元素在-720 m之下仍有存在多个异常浓集中心,表明矿体向深部仍有延伸趋势。矿区中部钻孔所揭露矿体的Cu×50/Fe值变化范围为1.50~2.77,指示为矿中;靠近东部钻孔所揭露矿体的Cu×50/Fe值变化范围为5.70~18.11,指示为矿上;矿体的Cu×50/Fe值由西向东具有明显的上升趋势,与Ι号矿体向SE侧伏的规律一致,进一步佐证矿体向深部可能存在较大的延伸。建议在矿区北东方向沿走向和倾向追索Ⅰ号矿体,在矿区东部寻找Ⅰ号矿体侧列再现或尖灭再现的新矿体。

The orebody occurs in the contact zone of Triassic carbonate rock and quartz diorite.The orebody has good continuity and tends to NE.The occurrence is steep.The deep orebody is distributed in a“step”shape,and has the characteristics of local expansion and shrinkage,pinch out and so on.In the center of the ore body,the ore is mainly copper iron ore,and gradually transits to copper ore to the southeast.According to the three-dimensional primary halo anomaly of the ore body,the concentration centers of Cu,Au and other metallogenic indicator elements are basically consistent with the spatial position of the ore body actually exposed by the borehole.There are still many abnormal concentration centers of As,Sb and other front indicator elements below-720 m,indicating that the ore body still has a trend of extending to the deep.The Cu×50/Fe value of the orebody exposed by the central borehole in the mining area ranges from 1.50 to 2.77,indicating that it is in the mine;the Cu×50/Fe value of the orebody exposed by the eastern borehole ranges from 5.70 to 18.11,indicating that it is on the mine.The Cu×50/Fe ratio of the ore body has an obvious upward trend from west to east,which is consistent with the regularitwuy of the east side of No.I ore body,which further proves that the ore body may extend to the deep.It is suggested that the No.1 ore body should be traced along the strike and dip in the northeast of the mining area,and the new ore body sidelined in the present or pinched reappearance should be found in the east of the mining area.