新疆萨瓦亚尔顿金矿床成矿特征及其与穆龙套型金矿床的异同性

METALLOGENIC CHARACTERISTICS OF SAWAYA'ERDUN GOLD DEPOSIT IN XINJIANG, AND THEIR SIMILARITIES TO AND DIFFERENCES FROM THOSE OF THE MURUNTAU-TYPE GOLD DEPOSITS

新疆萨瓦亚尔顿金矿床 ,是一个规模大、品位低 ,并具有细脉浸染和蚀变特征的金矿床。矿床赋存于上石炭统含碳碎屑岩建造中 ,矿化受构造破碎带的严格控制。组成矿石的基本矿物为硫化物、石英和方解石。金不均匀地分布于硫化物内。成矿溶液主要来自加热的循环地下水。成矿温度主要集中在 1 1 0～ 2 1 0℃范围内。成矿物质来源较复杂 ,既有赋矿地层的提供 ,又有来自下伏的碳酸岩盐和中基性火山岩 ,同时也有深部物质的参与。该矿床在地质背景、赋矿岩石、矿化形式、矿物组合、元素组合和成矿作用等方面均与邻国的穆龙套型金矿床具有可对比性 ,但也有其明显的特殊性———低温成矿作用特征。

The Sawaya'erdun gold deposit, discovered at the beginning of 1990's, is situated in the hinterland of southwestern Tianshan near northwestern Tarim Basin. The deposit is characterized by large reserves, low grade and intense alteration. The deposit occurs in the slightly metamorphosed Upper Carboniferous clastic rock formation characterized by flyschoid. The occurrence of orebodies is strictly restricted within the fractured strata. Sulfides are the dominant ore minerals. Electrum, and , secondly, native gold occur in sulfides unevenly. It is shown that the origin of the deposit is associated mainly with an ancient meteoric hydrothermal convection system. Temperatures range between 110～210℃. In the light of the rare earth element distribution patterns and the S, C, Si and Pb isotopic compositions, it is concluded that the ore forming materials were derived mainly from the country rocks and underlying rocks, partially deeper parts.As for its geological setting, ore hosted rock, mineral and element paragenesis, or metallogenic mechanism, the gold deposit is pretty similar to the Muruntau gold deposit and can be contrasted completely. But its particularity is low temperature mineralization