Timing, magnitude and geochemistry of major Southeast Asian volcanic eruptions: identifying tephrochronologic markers
Timing, magnitude and geochemistry of major Southeast Asian volcanic eruptions: identifying tephrochronologic markers
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DOI：
10.1002/jqs.3181
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发表时间：
2019-12-24
影响因子：
2.3
通讯作者：
Bergal-Kuvikas, Olga
中科院分区：
文献类型：
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作者：
De Maisonneuve, Caroline Bouvet;Bergal-Kuvikas, Olga
我们回顾了东南亚火山及其喷发历史的现有知识，并着重于确定代表主要爆发的火山灰年代学标志，以进一步促进未来的古气候和火山学研究。东南亚的41座火山大厦被Whelley等人（2015年）归类为大型火山口，因此已经或可能产生大型爆炸性喷发，火山爆炸指数（VEI）为6-8。不幸的是，只有20个这样的火山爆发已知的年龄，从1.2马到1991年，和更少的地球化学数据，可用于灰岩地层的相关性。来自不同地球动力区和不同来源的火山产物通常可以在基质玻璃成分的主要元素图（例如K2 O与CaO）上区分开来。然而，同一来源的多次喷发的区别往往需要额外的数据，如微量元素组成的基质玻璃和/或矿物成分。黑云母和磁铁矿成分（特别是MgO和TiO 2含量）似乎非常有区别。多达9个凝灰岩，除了3至4多巴凝灰岩可作为广泛的灰岩年代学标记，跨度范围从1.2至1.6马到最近。由于只有少数几次全新世大喷发已被很好地描述和定年，许多大的火山口仍未经研究，许多远端火山灰层仍然缺乏来源，更多的火山灰年代学标志物肯定可以在未来定义。
We review the current knowledge about Southeast Asian volcanoes and their eruption histories, and focus on identifying tephrochronologic markers representing major explosive eruptions in order to further future palaeoclimate and volcanological studies. Forty-one volcanic edifices in Southeast Asia have been classified as large calderas by Whelley et al. (2015) and thus have, or are likely to have, produced large explosive eruptions with a Volcanic Explosivity Index (VEI) of 6-8. Unfortunately, only 20 such eruptions have known ages, spanning from 1.2 Ma to 1991 ad, and fewer have geochemical data that can be used for tephrostratigraphic correlations. Volcanic products from different geodynamic regions and different sources can generally be distinguished on major element plots (e.g. K2O versus CaO) of matrix glass composition. However, the distinction of multiple eruptions from the same source often requires additional data such as trace element compositions of matrix glass and/or mineral compositions. Biotite, but also magnetite compositions (MgO and TiO2 content in particular) appear to be very discriminating. Up to nine tuffs in addition to the three to four Toba tuffs can be utilised as widespread tephrochronologic markers and span a range from 1.2 to 1.6 Ma to recent. As only a few Holocene major eruptions have been well characterised and dated, many large calderas are still unstudied, and many distal tephra layers are still lacking a source, more tephrochronologic markers can certainly be defined in the future.