山东栖霞香夼矿床深部地球化学成矿机理

Geochemical Metallogenic Mechanism of the Deep Xiangkuang Deposit in the Qixia Area of Shandong Province

山东栖霞香夼铜多金属硫化物矿床深部铜矿化延伸至-1200m以下,但该矿化体的形态分散且品位明显偏低。本研究利用电子显微技术、ICP-MS、X射线荧光光谱、AAS、ICP-AES等分析测试方法系统分析了矿床深部沿纵向与横向两个方向上定向采集的岩石样品。研究结果表明,香夼矿床矿化具有水平分带和垂直分带特征,具体表现为：在水平方向上,由西向东以铅-锌为主过渡到以铜为主的侧向分带;在垂直方向上,从上而下表现为铅-锌矿带-铜矿带、铜（钼）矿带的正向分带。花岗斑岩体和板岩内部均存在矿化体,矿化作用主要位于构造破碎蚀变带内,其中破碎带蚀变程度与矿化呈明显的正相关关系。矿化岩石矿物微形貌、微结构、成分及组合特征综合表明,尽管矿区板岩内部也存在大量的矿化体,但该矿床的矿化体与花岗斑岩紧密接触并呈现出密切的联系。地球化学和流体包裹体的研究结果显示,该矿化作用的成矿物质具有深源特征,成矿温度大致为230℃~350℃。成矿流体主要为岩浆水,并表现出壳幔流体相互混合的特征。

The copper mineralization in the deep Xiangkuang copper polymetallic sulfide deposit of Qixia in Shandong Province extends downward to a depth of 1200 m, where mineralized bodies are scattered and strikingly of low grade. This study used many methods including electron microscopy, ICP - MS, X - ray fluorescence spectrum, AAS and ICP - AES analysis to analyze the rock samples collected from the deep subsurface in both longitudinal and lateral directions. The results show that the ore deposit mineralization has horizontal and vertical zonation. Specifically, in the horizontal direction, from west to east is a dominant lead - zinc transition to copper dominance. In the vertical direction, from top to bottom is a positive zoning of lead - zinc mine - copper, copper （molybdenum） ore belts. There are mineralized bodies inside granite - porphyry and slate, and the mineralization is mainly pres- ent in fractured alteration zones, with a positive correlation between the alteration degree of the fracture zone and mineralization. The micro -morphology, mierostructure, composition and assemblage characteristics of ore minerals show that despite of a lot of mineralized bodies inside slate, the mineralized bodies of this deposit and granite - porphyry contact closely and show a close linkage. The research results of geochemistry and fluid inclusions indicate that the metallogenie materials of mineralization have deep sources. The ore - forming temperature was 230℃ ~ 350℃. The ore - forming fluids came from magmatic water mixed with crust - mantle fluids.