中国东南沿海大(中)型浅成中低温热液矿床—斑岩型矿床评价的地质准则、成矿模式及其找矿意义

MINEROGENETIC MODEL, PROSPECTING SIGNI-FICANCE AND GEOLOGICAL CRITERIA FOR EVALUATION OF LARGE-(MIDDLE-)SCALE EPITHERMAL-MESOTHERMAL DEPOSITS IN SOUTHEASTERN COAST OF CHINA

本文总结中国东南沿海高钾钙碱性—双峰式火山岩带中已勘查大中型矿床成矿环境的共性：矿床所处区域构造的部位、成岩与成矿时代、矿床与岩浆成因类型、火山构造及其基底构造控矿性、矿床与爆发角砾岩、矿床与矿化类型叠加与共生、矿化与蚀变的分带往、矿床定位深度与剥蚀深度。作者认为这八点可作为找寻与评价大（中）型矿床的地质准则。通过火山地质与矿床地质统一的研究提出本区晚中生代以火山为中心地热体系的成矿模式。并就三个方面作类比：①与现代火山地热体系成矿作用类比；②以紫金山高硫型浅成低温热液矿床与世界同类型矿床作比较；③与环太平洋其他火山岩带同类型矿床模式作类比．通过建立本区的模式与类比获得进一步找矿中值得重视的一些思路．

The paper makes a summary on the prugress of prospecting large-to middle-scale deposits in southeastern coast of China, where high-K CA series and basalt-rhyulite bimodal volcanic rocks are wide-outcropped. In view of the general characters abuut ore-forming settings of re-gional large-scale epithermal-mesothermal and porphyry deposits, eight aspects are given be-low, such as regional tectonic positions, synchronism or delay of minerogenesis compared with diagenesis, minerogenetic and magmatogenic types, composite ore-control of volcanic and basenyent tectonics, widespread cryptoexplosive breccthe, superposition and paragenesis of de-posits or .mineralization types, horizontal and vertical zonations of mineralised alteration, and positioning and denudation depths of deposits. All of these can be regarded as the geological criteria for prospecting and evaluating Iarge-scale deposits.Based on comparisons of large-scale deposits one by one and researches on ore-forming settings a minerogenetic model for regional epithermal-mesothermal and porphrry deposits is advanced, which is considered as a volcano-centred geothermal system. Furthermore, three aspects concerning this model by analogy are made. First, comparisons with modern volcano-assoctated Seothermal system reveal that both of them are comparable. Second, comparisons between Zijinshan, a representative high-sulphur epithermal deposit, and some deposits from North America, such as Sumitville , Julcani, Lake City (Ⅱ) and Red Hill, etc. indicate that they are sdriilar in mineroSenetic characters. Third，comparisons with other deposits of the same type from other regions of Circum-Pacific area are made. By means of these comparisons, the reasonableness of volcano-centred geothermal system is further demonstrated, and at the same time, some valuable enlightments are obtained, which concern prospecting for large-scale gold deposits situated inside volcanic rocks and porphyry deposits positioning in the root of a volcano.