云开地块基底演化与成矿作用

THE BASEMENT EVOLUTION AND MINERALIZATION OF YUNKAI MASSIF, SOUTH CHINA

云开地块位于广东和广西两省的毗邻地带，经历了基底形成和改造两个阶段。基底形成包括了古中元古代高州杂岩的沉积与变质、晚元古代云开群的沉积与变质、震旦系和早古生代地层的沉积和变质，在早古生代晚期作为整体转化为稳定地块。基底改造发生在加里东期之后，包括海西－印支期与燕山－喜山期两个阶段，基底岩石经历了断裂变质、重熔改造和构造活动。在基底演化过程中，物质进行了重新分布，一些元素得以富集成矿，使云开地区成为我国重要的银金-多金属矿床集中区。

YunKai massif, located at the juncture of Guangdong and Guangxi Province,belongs to Chledonidas. The Basement evolution of Yunkai massif includes two stages: basemntformation and rework. Further more the basement formtion envelops the sedimentation ofGaozhou Complex(Pt1 - 2) Paleoprotrosoic Erathem, Yunkai Group(Pt2) Sinian system and earlyPaloozoic strata, and their metamorphizm. It became craton at the end of early paleosoic era. Thebasement rework began after caledonian period, and was experienced through two tectonicmovement stages: Hercynian - Indosinian movement and Yanshan - Xirnalaya movement.Basement rocks were reworked by faulting metamorphism, remelting and faulting. Duringbasement evolution some materials were redistributed, as result, some useful elements enrichedand valuable deposits formed. The basement formation process associated with the sedimentarymineral deposits and source bed, metamorphic ore deposits and derived source bed. The basementrework process accompanied with usefull elements migration activition and deposit formation. Asresult the Yunkai area turned into Au - Ag and polymetallic concentration district.