长白山天池火山气象站期碱流岩辉石环带混沌吸引子的发现及意义
火山岩中矿物的成分环带中蕴含着其生长过程中岩浆成分和温压等物理状态的变化信息,对研究岩浆演化和火山喷发动力过程非常重要.长白山天池火山气象站期碱流岩辉石具有明显的环带结构,其成因尚未讨论.本文通过了辉石环带的电子探针分析,发现MgO和Na2O等元素的相对含量呈剧烈的振荡形态.同时,利用非线性时间序列分析的方法,对MgO元素沿辉石环带成分进行了相空间重构的探索性研究.结果发现,辉石环带成分时间序列的相空间吸引子为混沌吸引子.这说明辉石斑晶在生长时所处的系统具有高的自由度和高度的复杂性,其结晶和生长时周围岩浆的成分是高度非稳态和不平衡的.我们认为是岩浆房补给混合和热对流作用过程导致辉石所处的岩浆成...
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| Published in | 科学通报 Vol. 62; no. 30; pp. 3470 - 3478 |
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| Main Author | |
| Format | Journal Article |
| Language | Chinese |
| Published |
2017
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| Subjects | |
| Online Access | Get more information |
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| Summary: | 火山岩中矿物的成分环带中蕴含着其生长过程中岩浆成分和温压等物理状态的变化信息,对研究岩浆演化和火山喷发动力过程非常重要.长白山天池火山气象站期碱流岩辉石具有明显的环带结构,其成因尚未讨论.本文通过了辉石环带的电子探针分析,发现MgO和Na2O等元素的相对含量呈剧烈的振荡形态.同时,利用非线性时间序列分析的方法,对MgO元素沿辉石环带成分进行了相空间重构的探索性研究.结果发现,辉石环带成分时间序列的相空间吸引子为混沌吸引子.这说明辉石斑晶在生长时所处的系统具有高的自由度和高度的复杂性,其结晶和生长时周围岩浆的成分是高度非稳态和不平衡的.我们认为是岩浆房补给混合和热对流作用过程导致辉石所处的岩浆成分在高MgO、低MgO之间激烈振荡变化,形成了辉石环带成分的剧烈振荡.而这些补给-混合-对流的过程可能最终导致岩浆房超压而发生溢流喷发. |
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| Bibliography: | Tianchi volcano, comenditic lava, zoning pyroxene, nonlinear time series analysis, chaotic attractor, magma mixing 11-1784/N Mineral compositional analysis is a powerful tool for identifying both volcanic and petrogenetic processes. This property is observed because spatial variations in the composition of magmatic minerals record chemical and physical changes in the magma from which they crystallized. Thus, these variations can also be used to decipher the history of a magmatic system and its triggering mechanism prior to eruption. The Tianchi volcano, located in the Changbaishan volcanic region, is one of the most active and dangerous volcanoes in East Asia; however, the eruptional mechanism of most recent eruptions are not well-resolved, especially the comenditic lava flow in the Qixiangzhan stage, Tianchi volcano. We focused on the zoned patterns in pyroxene phenocrysts of the comenditic lava to decipher the magma process and triggering mechanism of this silicic lava eruption. We analyzed major and minor el |
| ISSN: | 0023-074X |