气候变化领域集成服务门户(CCPortal): Taking the pulse of volcanic eruptions using plagioclase glomerocrysts

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DOI	10.1016/j.epsl.2020.116596
	Taking the pulse of volcanic eruptions using plagioclase glomerocrysts
	McCarthy A.; Chelle-Michou C.; Blundy J.D.; Vonlanthen P.; Meibom A.; Escrig S.
发表日期	2020
ISSN	0012821X
卷号	552
英文摘要	Crystallization timescales in subvolcanic systems and the consequences of interaction between ascending magmas and gases remain largely unconstrained, as do links between these processes and monitoring signals at restless volcanoes. We apply diffusion chronometry to radially-oriented plagioclase and associated olivine in a glomerocryst from Tolbachik volcano (Kamchatka, Russia) to elucidate such processes. We show that cm-size glomerocrysts grow in a few days prior to, or during, eruption. Melt inclusions from these glomerocrysts show no compositional evolution during crystallization, implying growth in a melt-rich and dynamic environment. Volatile elements in melt inclusions show significant variability, with increasing CO2 as H2O decreases. This behaviour is inconsistent with normal degassing processes, and more likely reflects CO2-fluxing. On the basis of short residence timescales of glomerocrysts and sharp changes in melt inclusion volatile abundances, we propose that rapid (pre-)eruptive crystallization is controlled by rhythmic fluxing of magmatic H2O and CO2 through the sub-volcanic conduit. This implies that compositional zoning in plagioclase, from resorption textures to oscillatory zoning, record short-term CO2- and H2O-fluxing episodes, consistent with strombolian eruption dynamics. We propose that volcanic glomerocrysts represent the counterpart of vertical igneous layering (or comb layering) in shallow plutons. Magmatic layering and glomerocrysts dominated by radial plagioclase offer novel ways of targeting short-term crystallization and degassing processes in subvolcanic systems. © 2020 The Author(s)
关键词	nano-SIMS orbicules and comb layering plagioclase glomerocryst rapid crystal growth Tolbachik volcano volatile-fluxing
英文关键词	Analytical geochemistry; Carbon dioxide; Degassing; Feldspar; Structural geology; Textures; Zoning; Compositional evolution; Compositional zoning; Dynamic environments; Monitoring signals; Oscillatory zoning; Volatile abundances; Volatile elements; Volcanic eruptions; Volcanoes; crystal; crystallization; degassing; magma; mass spectrometry; melt inclusion; olivine; plagioclase; volcanic eruption; Kamchatka; Russian Federation; Tolbachik Volcano
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202776
作者单位	School of Earth Sciences, Wills Memorial Building, University of Bristol, United Kingdom; Department of Earth Sciences, ETH, Zürich, Switzerland; Department of Earth Sciences, University of Oxford, United Kingdom; Institut des Science de la Terre, University of Lausanne, Switzerland; Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, Switzerland; Center for Advanced Surface Analysis, Institute of Earth Sciences, University of Lausanne, Switzerland
推荐引用方式 GB/T 7714	McCarthy A.,Chelle-Michou C.,Blundy J.D.,et al. Taking the pulse of volcanic eruptions using plagioclase glomerocrysts[J],2020,552.
APA	McCarthy A.,Chelle-Michou C.,Blundy J.D.,Vonlanthen P.,Meibom A.,&Escrig S..(2020).Taking the pulse of volcanic eruptions using plagioclase glomerocrysts.Earth and Planetary Science Letters,552.
MLA	McCarthy A.,et al."Taking the pulse of volcanic eruptions using plagioclase glomerocrysts".Earth and Planetary Science Letters 552(2020).