胶西北上庄金矿床原生晕轴(垂)向分带特征及深部矿体预测的勘查地球化学标志

Axial/vertical zoning characteristics of primary halos and geochemical exploration indicators for deep ore body prognosis in Shangzhuang gold deposit,northwest Jiaodong peninsula, Shandong Province

文章应用格里格良原生晕分带指数方法,系统研究了上庄金矿单个矿体、矿区等不同取样系统的原生晕轴(垂)向分带特征。结果表明,上庄金矿床原生晕轴(垂)向分带序列及原生晕叠加模式在矿区范围内比较相似,因此,可利用典型矿体原生晕轴(垂)向分带规律来指导矿床内深部矿体的预测。适用于该矿区-750m以上的原生晕轴(垂)向分带序列为B-(Hg+W+Bi)-(As+Mn+Co)-Zn-(Au+Ag)-Pb-Mo。典型矿体原生晕叠加模式显示,沿垂直方向矿体间断部位原生晕出现头、尾晕同位叠加以及头、尾、近矿晕同位叠加2种情况,并均呈现出地球化学参数的剧烈波动。其中,前者是下部有盲矿体存在的反映,而后者则有可能既是深部有盲矿体存在,也是2个矿化带或大矿体间有小矿体存在的反映。依此认识对深部矿体开展了预测,部分靶区已获得成功验证。

The detection of ore bodies in the deep or outer parts of the resource-crisis mine is an urgent task in geological work of China. However, the adoption of most effective methods for exploration breakthrough remains an unsolved problem in ore-search practice. The authors utilized the primary halo zoning index method proposed first by Beus et al. （1977） to make a systematic study of characteristics of axial/vertical primary halo zoning in single ore body and mining area. It is revealed that the primary halo sequence, i.e., the order of element enrichment from the upper part to the lower part in the axiaL/vertical direction of the ore body, is stable within the mine area, and so does the primary halo superimposed model. Therefore, the utilization of the primary halo zoning sequence of a typical ore body to guide the deep metallogenic prognosis of other ore bodies in the mining area seems to be an effective means. The primary halo zoning sequence suitable for the mining area above - 750 m level is B-（Hg ＋ W ＋ Bi） -（As ＋ Mn ＋ Co）-Zn-（Au ＋ Ag）-Pb-Mo. In addition, the primary halo superimposed model from a typical ore body shows that there appear two circumstances between two ore bodies, one is the inplace superimposition of the trail halos and the front halos, and the other is the in-place superimposition of the front, trail and near-ore halos. The former might indicate the existence of other ore bodies underneath, whereas the latter might indicate the existence of not only blind ore bodies below the known ore body but also small ore bodies between two large ore bodies. Some metallogenic prognostic targets delineated on the basis of such consideration were successfully verified.