柴达木盆地南缘祁漫塔格—鄂拉山地区斑岩-矽卡岩矿床地质

Geology of porphyry and skarn type copper polymetallic deposits in southern margin of Qaidam Basin

柴达木盆地南缘祁漫塔格-鄂拉山地区发育斑岩-矽卡岩型铜多金属矿床,成矿主元素为Cu、Mo、Pb、Zn,大部分矿床伴生Au、Ag。斑岩型和矽卡岩型矿(化)体共生于同一个矿区之中,是这类矿床的一个重要特点。与成矿有关的侵入体是印支期的中酸性小岩体,它们具有浅成-超浅成和高侵位等特点。斑岩-矽卡岩矿床的成岩年龄和成矿年龄一致,形成于中三叠世至晚三叠世。它们是东昆仑造山带晚碰撞造山阶段壳-幔作用(幔源岩浆底侵-岩浆混合)的产物,与东昆仑地区这一时期的矽卡岩型铁多金属矿床、热液脉状多金属矿床,以及造山型金矿床共同构成了一个矿床成矿系列。

Copper polymetallic deposits of porphyry and skarn type are well developed in southern margin of the Qaidam Basin,whose ore-forming elements are mostly copper,molybdenum,lead and zinc with accompanying elements of gold and silver. A prominent feature of such ore deposits is that mineralizations of porphyry type and skarn type coexist in the same ore deposit. Intrusive rocks related to mineralization are Indosinian intermediate-acid small intrusive bodies assuming hypabyssal and high-level emplacement features. Rock-forming and ore-forming ages of these deposits are consistent,being Middle to Late Triassic. They were formed under the crust-mantle interaction during the late collision of East Kunlun orogeny,forming a metallogenic series with skarn-type iron polymetallic deposits and hydrothermal veinlike polymetallic deposits and orogenic gold deposits of this stage.