国外超大型浅变质细碎屑岩型金矿床的地质特征

国外浅变质碎屑岩型金矿床的含矿岩系以含碳和黄铁矿,夹火山物质和热水沉积物,金含量高为特征.在含矿岩系的沉积、成岩过程中,局部可以形成贫金的含矿层,少数情况下以至于形成金矿体.含矿岩系的变质作用可能形成金矿化,或为后来的成矿作用造成有利的物理和化学环境.岩浆作用为成矿作用提供了部分成矿物质,或为改造成矿作用提供热源和动力.金矿床受构造控制,位于地热正异常区,金矿床的形成与热水沉积成矿作用、变质成矿作用、岩浆期后热液成矿作用和大气降水改造成矿作用等有关.超大型浅变质碎屑岩金矿床的形成过程持续时间长,具有多期多阶段的特点.改造成矿作用在超大型浅变质细碎屑岩型金矿床形成中起重要作用,中生代形成的超大型金矿床中,构造岩浆活化作用叠加十分重要.

THE GEOLOGICAL CHARACTERISTICS OF ABROAD SUPERLARGE METAMORPHIC MICROCLASTIC ROCK TYPE GOLD DEPOSITS

おhe abroad rock series bearing metamorphic microclastic rock type gold deposits are characterized by containing carbon,pyrite,volcanic matter,hot water sediment and high content goldIn the sedimentation and diagenetic process of ore bearing rock series,gold poor ores might form locally;gold ore bodies even formed occasionallyThe metamorphism of ore bearing rock series might cause gold mineralization or favorite physical chemical conditon for the later gold ore formationThe magmatism in the mining areas presented a part of mineralization matter or heat source and motive power for reworking mineralizationThe deposits are defined by structures and found in positive terrestrial heat anomaly areasThe formations of gold deposits are related to hot water sedimentation,metamorphism,post magmatism hydrothermal mineralization and atmospheric water reworking mineralizationThe formation of superlarge metamorphic microclastic rock type gold deposits underwent a long process and was multi term and multi stageThe reworking process was important in the formation of the superlarge gold depositsIn the forming process of superlarge gold deposits during Mesozoic era,superimposing structural and magmatic activation are significant