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在加拿大地盾的苏必利尔省东部,金产于混合岩化副片麻岩区的变质铁建造之中。位于距英云闪长岩入体100m的主要金矿点,经受了类矽卡岩的变质作用,该变质作用出现于麻粒岩级变质作用的晚期。尽管矿化作用产于高级变质围岩之中,但它具有许多低级太古宙绿岩带金矿化作用的特征,例如:(1)富Au、As、S、Sb、W、U和FeO;(2)贱金属/金比值低;(3)金在毒砂中作为包体存在;(4)位于长英质侵入体附近;(5)富铁的碎裂围岩;(6)相近的成矿时间(大约2650Ma)。这种金矿化出现于变质作用的峰期附近,并代表了晚太古代广泛发育的地壳深部成矿作用体系。本文的主要结论是太古代金矿化作用的主要特征与深部地壳地质作用有关,而不是与上部地层如绿岩带的淋滤作用有关。
In the eastern part of the province of Superior, on the Canadian Shield, gold is built into metamorphic iron in a mixed petrified paragneiss zone. The main gold deposit, located 100 m from the Ying-diorite, has experienced metamorphic skarn-type metamorphism that occurred late in the granulite-grade metamorphism. Although mineralized in advanced metamorphic rocks, it has many gold mineralization features of low-grade Archean greenstone, such as: (1) rich Au, As, S, Sb, W, U and FeO; (2) the base metal / gold ratio is low; (3) gold is present as inclusions in the arsenopyrite; (4) is located near the Permian intrusions; (5) iron-rich fractured rock; (6) Mineralization time (about 2650Ma). This gold mineralization occurs near the peak of metamorphism and represents a deep crustal mineralization system that developed extensively in the Late Archean. The main conclusion of this paper is that the main features of the Archean gold mineralization are related to the deep crustal geology rather than to the leaching of the upper strata such as the greenstone belt.