长白山天池火山千年大喷发的岩浆过程

发布时间：2018-02-21 15:56

本文关键词： 天池火山千年大喷发碱流质喷发阶段粗面质喷发阶段岩浆混合岩浆过程模型　出处：《岩石学报》2017年01期 　论文类型：期刊论文

【摘要】：千年大喷发是长白山天池火山最近的一次大规模爆炸式喷发活动。本文在天池火口及周边的地质调查中发现,千年大喷发存在碱流质和粗面质两套堆积物,且具有岩浆混合现象。进一步岩相学与地球化学研究,证实千年大喷发应存在先后两个喷发阶段,即碱流质喷发阶段(SiO_2,~75%)和粗面质喷发阶段(SiO_2,~65%)。同时,通过微量元素和斑晶特征等分析认为两阶段的岩浆来自于两个独立的岩浆房,岩浆房平衡温度分别为743℃和862℃,相应深度约为5km和7~9km。另外,根据条带状岩浆的混合特征,认为喷发过程中碱流质与粗面质岩浆混合发生在上升通道中,排除岩浆房内混合的可能性。最后根据喷发过程和岩浆特征,综合提出了千年大喷发的岩浆过程模型。本文对千年大喷发的喷发过程和岩浆过程取得的新认识,增进了对天池火山活动习性的理解。
[Abstract]:The Millennium eruption of the Tianchi volcano in Changbai Mountain is a recent massive explosive eruption. The geological survey found in and around the Tianchi crater, the Millennium eruption of alkali liquid and trachytic two sets of deposits, with magma mixing phenomenon. Further petrographic and geochemical studies, confirmed the Millennium there has two eruption eruption phase, namely liquid alkali eruptive stages (SiO_2, ~75%) and trachytic eruption phase (SiO_2, ~65%). At the same time, through the analysis of trace elements and features that the two stage phenocryst magma from two independent magma chambers, the magma chamber equilibrium temperature were 743 DEG C and 862 degrees, the corresponding depth is about 5km and 7~9km. in addition, according to the characteristics of mixed banded magma, that the eruption process of alkali liquid and trachytic magma mixing occurred in the rising channel, excluding mixed magma chamber may be based on. The eruption process and magma characteristics have brought forward a large scale eruption magma process model comprehensively. In this paper, a new understanding of the eruption process and magma process of millennial eruption has enhanced the understanding of the activity habits of Tianchi volcanoes.

【作者单位】：中国地震局地质研究所活动构造与火山重点实验室;吉林省长白山天池火山监测站;
【基金】：国家自然科学基金项目(41302267) 中国地震局地质研究所基本科研业务专项(IGCEA1505)联合资助
【分类号】：P317.3

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