华南地区三叠纪矿床地质特征、成矿规律和矿床模型

华南以中生代成矿大爆发为特征,燕山期矿床成矿规律的研究程度较高,近年来发现越来越多的三叠纪矿床,但三叠纪矿床的分布规律和矿床模型是值得关注的重要科学问题。本文基于最新研究成果,论述华南三叠纪矿床地质特征和矿床类型,提出成矿规律,初步地建立成矿动力学模型。华南地区三叠纪矿床分布较为广泛,目前确定的46个三叠纪矿床分布于5个区带,形成于晚三叠世 (230~200 Ma),被划分为花岗岩有关的钨锡多金属矿床、侵入岩有关的远端金锑矿床、卡林型金矿床和MVT型铅锌矿床4种主要类型。在空间上,华南三叠纪矿床存在成矿元素分带性,由西向东依次为MVT型铅锌矿床、卡林型金矿床、侵入岩有关的远端金锑矿床、花岗岩有关的钨锡多金属矿床。华南5个成矿区带普遍存在印支期和燕山期的叠加成矿作用,在南岭西段桂北苗儿山—越城岭和滇东南老君山地区还发育加里东和印支期的叠加成矿作用。

Triassic deposits in South China: Geological characteristics,ore-forming mechanism and ore deposit model

South China is characterized by intensive, large-scale Mesozoic metal mineralization. The mechanism of ore formation during the Yanshanian period has been well studied. Recently, plentiful Triassic deposits have been discovered or recognized in South China, however, few studies are focused on their regional distribution pattern and ore deposit model. In this study, the geological characteristics, spatial-temporal distribution pattern and metallogeny of these Triassic deposits are summarized. So far, forty-six deposits of Late Triassic (230-200 Ma) have been discovered, mostly in five regions of South China. These deposits can be subdivided into four types based on mineralization styles. They, showing a zonal distribution from east to west, are the granite-related W-Sn deposits, the intrusion-related distal Au-Sb deposits, the Carlin-type Au deposits, and the MVT Pb-Zn deposits. The granite-related W-Sn deposits are situated to the south of the Carlin-type Au deposits. Multiple mineralization events took place within a single region as overprinting mineralization in the Indosinian and Yanshanian periods is commonly found in all five regions, and overprinting mineralization in the Caledonian and Indosinian periods was found in the Miaoershan-Yuchengling district of western Nanling and in the Laojunshan district of southeastern Yunan Province.