华南陆块成矿元素巨量聚集与分布

Accumulation and distribution of metallogenic elements in south China continent

以中国的区域化探全国扫面计划1﹕20万水系沉积物数据为基础,系统制作了华南陆块6个主要成矿元素(W、Sn、Au、Cu、Pb、Zn)1﹕250万地球化学空间分布图,并研究了这些元素巨量聚集的空间分布及其产出的地质背景。研究发现,华南三大成矿域成矿元素的聚集各有特色,高温成矿元素W、Sn主要分布于华夏地块,与中生代大花岗岩省成矿系统密切相关,两元素有很好的套合关系,异常的核心部分包含全球最主要的南岭W、Sn金属成矿省;巨量Au主要分布于扬子地块周边,有6处大规模聚集区,分别位于西秦岭、松潘、长江中下游、滇黔桂交界区、湘东-湘西、粤桂交界区;巨量Cu聚集区共5处,主要分布于长江中下游、西秦岭、三江、扬子陆块西南缘(以峨眉山玄武岩地幔柱区域为主体)和湘粤桂交界区;巨量Pb主要分布于华南陆块西南缘和华夏地块中东部(粤桂湘交界区和东南沿海成矿带);巨量Zn主要分布于华南陆块西南缘和粤桂湘交界区。这些成矿物质的最基本单元——元素的空间分布对于了解地质作用过程产生的巨量成矿物质聚集和就位机制,厘定分布范围和边界,聚焦找矿靶区具有重要意义。

The paper focused on the spatial distributions of six major metallogenic elements （W, Sn, Au, Cu, Pb, Zn） and their relationship with geological settings based on geochemical data of 1 ： 200,000 stream sediment samples from the Regional Geochemistry-National Reconnaissance （RGNR） project in South China continent. It was found that different element accumulations occur in three metallogenic provinces in the south China continent. Huge amount of tungsten and tin accumulations are mainly distributed in the Cathaysian Block, which are closely related to the metallogenic system of Mesozoic granite province. The anomaly center contains the world＇s largest tungsten-tin metallogenic province in the Nanling region. Huge amount of gold accumulation is mainly distributed around the Yangtze Craton with 6 geochemical provinces, including Qinling, Songpan, the Middle and Lower Reaches of the Yangtze River, the border area of Yunnan, Guizhou and Guangxi provinces, Eastern-Western Hunan, and the border area of Guangdong and Guangxi provinces. The copper accumulation areas are mainly located in the Middle and Lower Reaches of the Yangtze River, West Qinling, the Jinsha-Lancang-Nu rivers, the southwestern margin of Yangtze Craton related to the mantal plume of Emeishan basalts, the border area of Hunan, Guangdong and Guangxi provinces. The enormous lead accumulation areas are mainly distributed in southwest China, the middle and east of Cathaysian orogenic belt （the border area of Guangdong, Guangxi and Hunan provinces, and the coastal metallogenic belt of Southeastern China）. Zinc accumulation areas are mainly located in southwest China and the border area of Guangdong, Guangxi and Hunan provinces. The huge accumulations of elements have made basic contributions to formation of mineralization provinces and the spatial distribution of elements is crucial for us to determine distribution boundaries of the metallogenic provinces, and locate new mineralization targets.