山东省莱州-安丘铁成矿带成矿规律探析

Metallogenic Regularity of Laizhou-Anqiu Iron Ore-forming Belt in Shandong Province

成矿带内主要赋矿层位为古元古代粉子山群和荆山群变质地层,铁矿成因可归纳3种成因类型,即层控沉积变质型、受断裂构造控制的高-中温热液型和岩浆熔离型。沉积变质铁矿层控特征明显,其赋存层位为古元古代粉子山群小宋组;热液型铁矿严格受断裂构造、层间构造所控制,不论在垂向或水平方向上与蛇纹岩或磁铁蛇纹岩均呈过渡关系,矿体多呈形态复杂的透镜状产于古元古代粉子山群小宋组和荆山群野头组祥山段;岩浆熔离型铁矿位于昌邑-大店断裂与平度断裂相接部位,成矿母岩为古元古代莱州岩套西水夼细粒变辉长岩,矿体赋存于古元古代荆山群野头组中。

Major ore bearing layers in metallogenic belt is Paleoproterozoic Fezishan and Jingshan Group metamorphic stratigraphy.the causes of iron deposits can be summarized into three kinds of types,they are strata bound sedimentary metamorphic type iron deposit,high mesothermal type and magma dif-ferentiation by liquation type controlled by the faults.Characteristics of strata bound in sedimentary met-amorphic deposit is obvious.Its occurrence layers are Xiaosong formation in Paleoproterozoic Fenzishan group.Hydrothermal deposit is strictly controlled by fault structures and interlayer structures.Whether in vertical or horizontal direction,it has the transition relationship with serpentinite or magnet serpentine. Ore bodies often occurred in Xiaosong formation of Paleoproterozoic Jingshan group and Xiangshan section in Yetou formation of Fenzishan group with a plex form of lenticular form.Magmatic differentiation by li-quation type iron deposit locates in the connection part of Changyi Dadian fault and Pingdu fault.Ore forming parent rocks are Xishuikuang fine grained rock of Paleoproterozoic Laizhou rock suite.Ore bodies occur in Yetou formation of Palaeoproterozoic Jingshan group.