气候变化领域集成服务门户(CCPortal): Chlorine Heterogeneity in Volcanic Glass as a Faithful Record of Silicic Magma Degassing

CCPortal

DOI	10.1029/2020JB021195
	Chlorine Heterogeneity in Volcanic Glass as a Faithful Record of Silicic Magma Degassing
	Yoshimura S.; Nakagawa M.
发表日期	2021
ISSN	21699313
卷号	126 期号:5
英文摘要	Degassing processes occurring within silicic magma, such as bubble growth, bubble resorption, the welding of magma fragments, and open-system gas loss are crucial in the control of volcanic eruption and lava emplacement, yet their details are still debated. To examine the possibility that these degassing processes are recorded in volcanic glass as heterogeneous Cl distribution patterns, we experimentally simulated these processes by heating rhyolitic obsidian and analyzed the distribution of Cl content in the recovered sample. The results showed that, for bubble growth, Cl diffused toward the bubble interface, leading to Cl depletion around the bubble. For bubble resorption, Cl was discharged from the bubble to the melt, leading to Cl enrichment in the ambient melt. For welding of magma fragments, Cl was depleted near the welded interface because each fragment had degassed Cl at the surface before the welding took place. For open-system gas loss, Cl exsolved at the bubble interface while the bubble itself was being collapsed into a chain of small bubbles and a Cl-depleted tail. These results indicate that Cl distribution is a reliable record of the experienced degassing processes. We then analyzed the Cl distribution in silicic lava from Naruko volcano, Japan, to study the gas flow mechanism. We observed that the glassy matrix was progressively corroded into porous crystalline material. The interface of the glass was highly enriched in Cl. We conclude that a Cl-rich gas fluxed through hot lava and corroded the glass, developing a porous, gas-permeable region. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	bubble growth; bubble resorption; chlorine; corrosion; degassing; open-system gas loss; welding
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187176
作者单位	Department of Earth and Planetary Sciences, Hokkaido University, Sapporo, Japan
推荐引用方式 GB/T 7714	Yoshimura S.,Nakagawa M.. Chlorine Heterogeneity in Volcanic Glass as a Faithful Record of Silicic Magma Degassing[J],2021,126(5).
APA	Yoshimura S.,&Nakagawa M..(2021).Chlorine Heterogeneity in Volcanic Glass as a Faithful Record of Silicic Magma Degassing.Journal of Geophysical Research: Solid Earth,126(5).
MLA	Yoshimura S.,et al."Chlorine Heterogeneity in Volcanic Glass as a Faithful Record of Silicic Magma Degassing".Journal of Geophysical Research: Solid Earth 126.5(2021).