胶北荆山群山西石墨矿地质特征及找矿潜力

Geological Characteristics and Prospecting Potential of Shanxi Graphite Deposit in Jingshan Group in Jiaobei Area

摘要:

平度市山西石墨矿位于胶北隆起之南缘，赋存于古元古代荆山群陡崖组徐村石墨岩系段，属沉积变质型矿床。圈定2个石墨矿化带共计12个矿体，其中KH1矿化带位于山西村—焦疃村向斜之东翼，深部未封闭。石墨矿体呈似层状展布，倾向NW，倾角18°～37°；沿走向延伸长200.00～1 718.30 m，沿倾向延伸168.30～608.20 m，平均厚度1.75～17.81 m；平均品位2.02%～6.05%。矿石自然类型主要为石墨黑云斜长片麻岩型，次为石墨黑云变粒岩型。徐村段是石墨矿找矿的地层标志，低阻高极化为激电异常标志，褶皱构造是石墨矿找矿的构造标志。本文通过分析成矿地质背景、矿床特征及矿石特征，探讨了石墨矿床成因，总结了找矿标志；通过分析褶皱构造与石墨成矿之间及物探异常与石墨成矿之间的关系，预测深部找矿潜力及外围找矿潜力，为今后该地区的石墨找矿指明了方向。

Abstract:

Shanxi graphite deposit in Pingdu city is located in southern Jiaobei uplift. It occurs in Xucun limestone formation of Jingshan group in Paleoproterozoic era. It is a sedimentary metamorphic deposit. Two graphite mineralization zones with 12 ore bodies have been circled. Among them, KH1 mineralization zone is located in east wing of syncline in Shanxi village—Jiaotuan village, and the deep part is not closed. The graphite ore body is distributed in a layered manner with the trend of NW, and an inclination angle is 18 °~37 °. It stretches along the direction for a length of 200.00~1718.30m, and extends along the dip for the length of 168.30~608.20m. The average thickness is 1.75~17.81m, and average grade is 2.02%~6.05%. The main natural type of ores is graphite biotite plagioclase gneiss type, followed by graphite biotite granulite type. Xucun section is a stratigraphic marker for graphite mineral exploration, low resistance and high polarization are indicators of induced polarization anomalies, and fold structures are structural markers for graphite mineral exploration. Through analyzing geological background of mineralization, deposit characteristics and ore characteristics, the origin of graphite deposits has been studied, and prospecting criteria has been summarized. Through analyzing the relationship between geophysical anomalies and graphite mineralization, exploration potential of the periphery has been predicated. It will provide the direction for graphite exploration in the future.