| In this paper, the author deals with the metallogenic characteristics and forecast of gold deposits in Fujian Province. On the basis of the geologic scientific achievements yielded by forefathers, the author discusses the geologic background of Fujian Province in great detail, which provides the basic data for studying the ore control factors, the metallogenic law and the forecast of gold deposits. Mainly thinking over ore-bearing rock series and giving consideration to ore-forming process, the author divides the gold deposits in Fujian into four categories which include metamorphic rock category, volcanic rock category, sedimentary clastic rock category and igneous rock intrusive contact category. By the study of metallogenic geologic characteristics of the various gold deposits, the author sets up the ore-forming model of some typical deposits such as Shuangqishan deposit and Zhijinshan deposit etc.. It is considered that the gold deposits of metamorphic rock category and the volcanic rock category are the main gold-prospecting categories and Carlin gold deposit and Mulongtao gold deposit are the potential categories in Fujian Province. The majority of Fujian gold deposits can be put under Predevonian regional metamorphism-epigenetic thermal fluid telescoped and regenerated gold metallogenic system and Yanshan tectonic-magmatic thermal fluid gold metallogenic system. After making detailed research on ore-controlling factors, the author points out that gold deposits in Fujian resulted from the various geologic processes such as sedimentation, metamorphism, tectonism and magmatism. It is believed that the distribution of gold deposits in Fujian is controlled by regional deep-seated structure and Precambrian volcanic flysch formation containing charcoal is main gold source rock. The accumulation of gold is closely related with Yanshan granitic magma intrusion. The author summarizes the distribution law of gold depositsof Fujian in space and time and studies the metallogenic epoch using the method of isotopic geochronology and geologic analysis. It suggests that gold accumulation occurred in the every main stage of geologic history of Fujian from Late-Archaean era to Quaternary period but the scale and the feature of the gold accumulation are different in different stage and Yanshan metallogenic epoch is the most important period of mineralization of Fujian gold deposits. The ore-finding indexes of gold deposits of metamorphic rock category, volcanic rock category and intrusive igneous rock contact category have been summarized. Basing on the above research and fully using geologic, geophysical, geochemical and remote-sensing etc. data, the author determines seven order IV metallogenic provinces and seventeen order V metallogenic provinces in Fujian and discusses the minerogenetic geologic characteristics and gold-finding direction of the four important order IV metallogenic provinces(Jianning-Taining, Youxi-Dehua, Zhenghe-Jianou and Jianyang Changping-Dajinshan). All the order V metallogenic provinces are classified and the their geologic features and main gold-prospecting categories are briefly introduced. Selecting Youxi-Dehua-Yongtai , Zhenghe , Taining and Shanghang prospecting metallogenic provinces (total area 2516 km2), which have good gold-finding prospective and relatively rich data, and using the method of characteristic analysis and information extraction to seek gold prospecting target , the author builds the gold deposit forecast models of metamorphic rock category and the volcanic rock category, determines 86 good gold-finding units in Fujian and assesses the gold resource extent of the order V prospecting metallogenic provinces in Shanghang, Taining, Zhenghe, and Youxi-Dehua-yongtai and Jianyan, .which provides important reference basis for seeking gold deposits in next survey.
|
PDF Full Text Request