一种新类型铜矿床的地球化学特征及其热水沉积成因

对兰坪－思茅沉积盆地几个代表性脉状铜矿床的研究发展，矿石构造以角砾状为主；金属矿物组合中出现较多的黝铜矿系列矿物（Ｃｕ１２Ｓｂ４Ｓ１３－Ｃｕ１２Ａｓ４Ｓ１３），约占金属矿物总量的５０％以上，部分矿石达８０％以上，其中尤以砷黝铜矿占优势；矿床的元素组合以Ｃｕ－Ａｓ－Ｓｂ－Ａｇ－Ｚｎ－（Ａｕ）－（Ｈｇ）－（Ｃｏ）－（Ｇａ）为特征；脉石矿物的稀土元素表现出特异的富中组稀土（Ｓｍ－Ｈｏ）、弱或无铕异常的曲

GEOCHEMICAL CHARACTERISTICS AND THEIR HYDROTHERMAL SEDIMENTARY GENESIS OF A NEW TYPE OF COPPER DEPOSIT

This paper reports the geological and geochemical characteristics of some typical vein copper deposits in Lanping-Simao basin,Yunnan province and discusses their hydrothermal genesis.Most of these copper deposits are located in proximity to the major active faults or the contemporaneous faults.Ore structures are mainly brecciated and massive.Metal mineral association is characterised by abundant tetrahedrite-tennantite series (Cu 12 Sb 4S 13 -Cu 12 As 4S 13 ),especially the tennantites.Element association is characterised by Cu-As-Sb-Ag-Zn-(Au)-(Hg)-(Co)-(Ga).REE patterns of vein minerals show an enrichment of middle REE (Sm-Ho) and a weak or no europium anomaly.These features,combined with the analysis of mineralization environment,lead us to conclude that the vein copper deposits in this area was formed during the continental hydrothermal sedimentation and hydrothermal boiling in the shallow portion was their main metallogenetic mechanism.They thus represent a new type of copper deposit in genetic sense.