DOI: 10.1016/j.epsl.2021.117016
论文题名: In situ quantification of crystallisation kinetics of plagioclase and clinopyroxene in basaltic magma: Implications for lava flow
作者: Le Gall N. ; Arzilli F. ; La Spina G. ; Polacci M. ; Cai B. ; Hartley M.E. ; Vo N.T. ; Atwood R.C. ; Di Genova D. ; Nonni S. ; Llewellin E.W. ; Burton M.R. ; Lee P.D.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2021
卷: 568 语种: 英语
中文关键词: basalt
; crystallisation
; lava flow
; X-ray microtomography
英文关键词: Atmospheric pressure
; Basalt
; Feldspar
; Nucleation
; Textures
; Tomography
; Viscosity
; Volcanoes
; Basaltic magma
; Clinopyroxenes
; Complex Processes
; Crystal fraction
; Crystal-size
; Flow dynamics
; Lava flows
; Real- time
; Volcanic eruptions
; X ray microtomography
; Crystallization
; basalt
; clinopyroxene
; crystallization
; lava flow
; magma
; nucleation
; plagioclase
; reaction kinetics
; real time
; X-ray tomography
英文摘要: Crystallisation is a complex process that significantly affects the rheology of magma, and thus the flow dynamics during a volcanic eruption. For example, the evolution of crystal fraction, size and shape has a strong impact on the surface crust formation of a lava flow, and accessing such information is essential for accurate modelling of lava flow dynamics. To investigate the role of crystallisation kinetics on lava flow behaviour, we performed real-time, in situ synchrotron X-ray microtomography, studying the influence of temperature-time paths on the nucleation and growth of clinopyroxene and plagioclase in an oxidised, nominally anhydrous basaltic magma. Crystallisation experiments were performed at atmospheric pressure in air and temperatures from 1250 °C to 1100 °C, using a bespoke high-temperature resistance furnace. Depending on the cooling regime (single step versus continuous), two different crystal phases (either clinopyroxene or plagioclase) were produced, and we quantified their growth from both global and individual 3D texture analyses. The textural evolution of charges suggests that suppression of crystal nucleation is due to changes in the melt composition with increasing undercooling and time. Using existing viscosity models, we inferred the effect of crystals on the viscosity evolution of our crystal-bearing samples to trace changes in rheological behaviour during lava emplacement. We observe that under continuous cooling, both the onsets of the pāhoehoe-‘a‘ā transition and of non-Newtonian behaviour occur within a shorter time frame. With varying both temperature and time, we also either reproduced or approached the clinopyroxene and plagioclase phenocryst abundances and compositions of the Etna lava used as starting material, demonstrating that real-time synchrotron X-ray tomography is an ideal approach to unravel the final solidification history of basaltic lavas. This imaging technology has indeed the potential to provide input into lava flow models and hence our ability to forecast volcanic hazards. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165557
Appears in Collections: 气候变化与战略
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作者单位: Department of Mechanical Engineering, University College London, London, WC1E 7JE, United Kingdom; Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell, Oxfordshire, OX11 0FA, United Kingdom; Department of Earth and Environmental Sciences, University of Manchester, Manchester, M13 9PL, United Kingdom; School of Metallurgy and Materials, University of Birmingham, Birmingham, B15 2TT, United Kingdom; Diamond Light Source Ltd., Didcot, OX11 0DE, United Kingdom; Bayerisches Geoinstitut, Universität Bayreuth, Bayreuth, 95440, Germany; University of Manchester at Harwell, Didcot, OX11 0DE, United Kingdom; Department of Earth Sciences, Durham University, Durham, DH1 3LE, United Kingdom
Recommended Citation:
Le Gall N.,Arzilli F.,La Spina G.,et al. In situ quantification of crystallisation kinetics of plagioclase and clinopyroxene in basaltic magma: Implications for lava flow[J]. Earth and Planetary Science Letters,2021-01-01,568