大兴安岭的大陆火山岩及其矿化作用

    CONTINENTAL VOLCANIC ROCKS IN THE GREATER KHINGAN MOUNTAINS AND THEIR MINERALIZATION

    • 摘要: 大兴安岭是我国著名的中生代火山活动带,它具有鲜明的大陆火山活动特点。本文以大兴安岭中段的实际资料为基础,对中生代火山活动带的大陆火山岩的地质及其矿化作用特点作一初步论述。

       

      Abstract: The earliest continental volcanic rocks in the study area were formed in the Triassic, the Jurassic volcanic rocks are the dominant constituent in the Greater Khingan volcanic belt, and the Cretaceous volcanic rocks represent the uppermost horizon of the Mesozoic volcanic rocks in the Greater Khingan area. From early to later times four eruptive cycles may be distinguished. The composition of the initial magma in each cycle tends to be basic and that of the late-stage magma tends to be acidic-alkaline. The SI valus ranges between 0.8 and 21.2, suggesting that the magma has undergone strong differentiation. There are three types of eruption in the Greater Khingan volcanic belt, the central, fissure and multi-central types. The rocks formed are mainly of eruptive facies and eruptive-sedimentary facies. The remnant volcanic apparatuses include calderas and volcanic domes. The useful products relating to volcanic activity include metallic and nonmetallic minerals as well as hot water resources.

       

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