气候变化领域集成服务门户(CCPortal): Preeruptive P-T Conditions and H2O Concentration of the Aso-4 Silicic End-Member Magma Based on High-Pressure Experiments

CCPortal

DOI	10.1029/2019JB018481
	Preeruptive P-T Conditions and H2O Concentration of the Aso-4 Silicic End-Member Magma Based on High-Pressure Experiments
	Ushioda M.; Miyagi I.; Suzuki T.; Takahashi E.; Hoshizumi H.
发表日期	2020
ISSN	21699313
起始页码	no
卷号	125 期号:3
英文摘要	To constrain the preeruptive physical and chemical conditions (pressure, temperature, H2O content, and fO2) of the most recent and largest eruption (Aso-4) of Aso volcano, Japan, we compared phase assemblages and chemical compositions of erupted material with those of experimentally determined run charges of the silicic end-member magma of Aso-4 (the KJ5665 pumice and MY5774 welded lens from the Aso-4 pyroclastic flow deposit; SiO2 = 70.5 wt %). Experimental conditions were as follows: starting material = KJ5665 pumice, pressure = 100–700 MPa, temperature range = 810–950 °C, and injected H2O content = 2.9–6.7 wt %. The starting material comprised mainly rhyolitic glass with plagioclase, orthopyroxene, magnetite, and ilmenite phenocrysts. Hornblende phenocrysts are not found on cross sections of the KJ5665 pumice. Core compositions of these phenocrysts are unimodal. Using the magnetite-ilmenite thermometer, the preeruptive magmatic temperature and fO2 of KJ5665 were estimated to be ~900 °C and Nickel-Nickel oxide (NNO) +1.1 log units, respectively. Run products contain plagioclase (An20–48), orthopyroxene (Mg# = 53–72), magnetite, ilmenite, biotite, and K-feldspar. Hornblende was not observed. Preeruptive conditions of the silicic end-member magma of the Aso-4 eruption are estimated to be ~900 °C, ≤ 300 MPa, and ≤ 3 wt % H2O. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Aso volcano; Aso-4; high-pressure experiments; preeruptive P-T conditions; silicic magma chamber
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/187916
作者单位	Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan; Guangzhou Institute of Geochemistry, Chinese Academy of Science, Guangzhou, China
推荐引用方式 GB/T 7714	Ushioda M.,Miyagi I.,Suzuki T.,et al. Preeruptive P-T Conditions and H2O Concentration of the Aso-4 Silicic End-Member Magma Based on High-Pressure Experiments[J],2020,125(3).
APA	Ushioda M.,Miyagi I.,Suzuki T.,Takahashi E.,&Hoshizumi H..(2020).Preeruptive P-T Conditions and H2O Concentration of the Aso-4 Silicic End-Member Magma Based on High-Pressure Experiments.Journal of Geophysical Research: Solid Earth,125(3).
MLA	Ushioda M.,et al."Preeruptive P-T Conditions and H2O Concentration of the Aso-4 Silicic End-Member Magma Based on High-Pressure Experiments".Journal of Geophysical Research: Solid Earth 125.3(2020).