关键词: 胶西北地区, 金矿, 预测要素, 预测区

Abstract:

Based on ‘metallogenetic series of mineral deposits’ proposed by Chen Yuchuan, authors pick up five key prediction factors and establish regional predicting models combined with metallogenetic characteristics from typical deposits. By the methodology of deposit modeling and integrated geological information, four essential gold ore-forming factors are concluded, which are Mesozoic Linglong admellite and Guojialing granodiorite, ore-controlling and ore-forming factors caused by extensional tectonic environment under intensive subduction settings, Jiaodong intrusive rock within Jiaodong tectonic magma belt under magma arc tectonic background in continental margin, as well as NNE and NE ductile and brittle fault belt. The important ore-controlling factors of gold deposits are presented as follows, Jiaodong superficial rock system and Early-Paleozoic subducted additional complex, late-Yanshanian mineralization, natural gold and pyrite assemblage, and wall-rock alteration of potassium and beresitization. Besides, there are four clues indicating gold deposit, including regional gravity-magnetic anomalies, aeromagnetic anomalies, stream sediment anomalies and natural placer mineral anomalies. Authors used predicting models to plot prediction zone relying on integrated predicting factors. The boundaries of prediction zone are defined by ore-bearing texture, gold geochemical exploration, placer mineral abnormal features, gravity anomaly gradient belt, favorable magnetic field, etc. Moreover, the deep boundaries are further confirmed by the accurate scope of controlling-ore texture, controlling depth of proved ore bodies and possible extensional features of deep ore bodies. Total 63 predicting potential regions are proposed, including 17 A-grade ones, 11 B-grade ones and 35 C-grade ones. In addition，gold potential resources of total prediction zones are estimated quantitatively, which are 3 250 tons in less than 2 km depth according to different area, segment, depth and grade respectively.