Timing, magnitude and geochemistry of major Southeast Asian volcanic eruptions: identifying tephrochronologic markers

Abstract

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. K 2 O 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 TiO 2 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.

Speleological and environmental history of Lida Ajer cave, western Sumatra

“…If indeed this unit preserved pyroclastic sediments, then several large eruptions on Sumatra may have provided the source of the sediments that would have entered the cave as a re-depositional fraction. These include Toba (74.2 ± 0.2 ka; [ 33 ]), Maninjau (52 ± 3 ka; [ 34 ]) or Masurai (33 ka; [ 35 ]) (see also [ 36 ]). If our proposed scenario is correct, then the volcanoclastics of unit 6 would be constrained in age between unit 4 (less than 88 ka; 2-sigma lower range of 66 ± 22 ka) and unit 7 (greater than 58 ka; 2-sigma lower range of 68 ± 10 ka; see below), consistent with the Toba eruption (74.2 ± 0.2 ka; [ 33 ]).…”

The Origin of Transparent and Non-Transparent White Pumice: A Case Study of the 52ka Maninjau Caldera Forming Eruption, Indonesia

“…Previous researchers have shown that Maninjau pumices have similar and homogeneous bulk and glass compositions (Leo et al 1980, Alloway et al 2004, de Maisonneuve et al 2020).…”

Crossing new frontiers: extending tephrochronology as a global geoscientific research tool

“…(2020) to reconstruct the crustal level of the magma reservoirs, their order of eruption, and their dispersal. Also focussing on Southeast Asia, Bouvet de la Maisonneuve and Bergal‐Kuvikas (2020) provide a review of the present knowledge of the volcanic history and tephrochronological potential of the region. Regionally, there are over 750 volcanoes and 41 calderas thought to have been formed by VEI 6‐8 eruptions.…”

“…Regionally, there are over 750 volcanoes and 41 calderas thought to have been formed by VEI 6‐8 eruptions. Understanding their history is highly important as they can pose a significant hazard to the ~600 million people who live in the region and, because it lies close to the equator, large eruptions can have a significant impact on global climate (Bouvet de la Maisonneuve and Bergal‐Kuvikas, 2020). This review compiles published data on the timing, magnitude, geochemistry and mineralogy of the Quaternary volcanic deposits studied to date.…”