DOI: 10.1038/ngeo1709
论文题名: Highly vesicular pumice generated by buoyant detachment of magma in subaqueous volcanism
作者: Rotella M.D. ; Wilson C.J.N. ; Barker S.J. ; Wright I.C.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2013
卷: 6, 期: 2 起始页码: 129
结束页码: 132
语种: 英语
Scopus关键词: buoyancy
; caldera
; clast
; explosive volcanism
; magma
; oceanic current
; pumice
; submarine volcano
; volcanic eruption
; volcanism
; Kermadec Arc
; Pacific Ocean
英文摘要: Many submarine caldera volcanoes are blanketed with deposits of highly vesicular pumice, typically attributed to vigorous explosive activity. However, it is challenging to relate volcanic products to specific eruptive styles in submarine volcanism. Here we document vesicularity and textural characteristics of pumice clasts dredged from the submarine Macauley volcano in the Kermadec arc, southwest Pacific Ocean. We find that clasts show a bimodal distribution, with corresponding differences in vesicle abundances and shapes. Specifically, we find a sharp mode at 91% vesicularity and a broad mode at 65-80%. Subordinate clasts show gradients in vesicularity. We attribute the bimodality to a previously undocumented eruptive style that is neither effusive nor explosive. The eruption rate is insufficient to cause magma to fragment explosively, yet too high to passively feed a lava dome. Instead, the magma foam buoyantly detaches at the vent and rises as discrete magma parcels, or blebs, while continuing to vesiculate internally. The blebs are widely distributed by ocean currents before they disintegrate or become waterlogged. This disintegration creates individual clasts from interior and rim fragments, yielding the bimodal vesicularity characteristics. We conclude that the generation and widespread dispersal of highly vesicular pumice in the marine environment does not require highly explosive activity. © 2013 Macmillan Publishers Limited. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106858
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: School of Geography, Environment and Earth Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand; National Oceanography Centre, University of Southampton Waterfront Campus, Southampton SO14 3ZH, United Kingdom
Recommended Citation:
Rotella M.D.,Wilson C.J.N.,Barker S.J.,et al. Highly vesicular pumice generated by buoyant detachment of magma in subaqueous volcanism[J]. Nature Geoscience,2013-01-01,6(2)