阿尔泰晚古生代两类火山岩建造及成矿特征

TWO DIFFERENT VOLCANIC FORMATIONSAND ASSOCIATED MINERALIZATION OF LATE PALEOZOIC IN ALTAY

新疆阿尔泰晚古生代火山岩主要发于育于泥盆系和石炭系 ,泥盆系火山岩主要是细碧岩—角斑岩—石英角斑岩建造 ,它们产于海相环境 ,具有地幔成分 ;石炭系火山岩主要是流纹岩—英安岩—安山岩建造 ,它们产出于海陆过渡相—陆相环境 ,属于地壳成分。这两种火山岩建造的岩石学、岩石化学和微量元素地球化学均有明显不同 ,各种地质条件表明 ,泥盆系火山岩产于裂谷拉张环境 ,而石炭系火山岩产于造山挤压环境。由于两类火山岩的成因不同 。

The volcanic rocks of the late Paleozoic mainly occur in the Devonian and Carboniferous.Those of the Devonian are mostly spilite- keratophyre- quartz- keratophyre formation of marine environment with mantle compositions. While those of the Carboniferous are rhyolite- doctite- andesite formation of transi- tional- continental environment with crustal compositions.The obvious difference of two volcanic rock suits in petrology,petrochemistry and trace element geochemistry shows that the Devonian ones were formed in a rift- extension environment,while the Carboniferous in an orogenic compression environment.The different origin leads to different metallogenic characteristics of metal minerals associated with the volcanics.