DOI: 10.1016/j.epsl.2020.116539
论文题名: The architecture of intrusions in magmatic mush
作者: Carrara A. ; Burgisser A. ; Bergantz G.W.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 549 语种: 英语
中文关键词: CDF-DEM
; density contrast
; granular mechanics
; intrusion
; magma
; mush
英文关键词: Computational fluid dynamics
; Computational geometry
; Crystals
; Numerical methods
; Compositional evolution
; Granular dynamics
; Horizontal layers
; Host materials
; Physical parameters
; Physical process
; Rayleigh-Taylor instabilities
; Viscosity contrast
; Network architecture
; computational fluid dynamics
; computer simulation
; discrete element method
; igneous intrusion
; magma
; magma chamber
; numerical model
; upper crust
英文摘要: Magmatic reservoirs located in the upper crust have been shown to result from the repeated intrusions of new magmas, and spend much of the time as a crystal-rich mush. The geometry of the intrusion of new magmas may greatly affect the thermal and compositional evolution of the reservoir. Despite advances in our understanding of the physical processes that may occur in a magmatic reservoir, the resulting architecture of the composite system remains poorly constrained. Here we performed numerical simulations coupling a computational fluid dynamics and a discrete element method in order to illuminate the geometry and emplacement dynamics of a new intrusion into mush and the relevant physical parameters controlling it. Our results show that the geometry of the intrusion is to first order controlled by the density contrast that exists between the melt phases of the intrusion and resident mush rather than the bulk density contrast as is usually assumed. When the intruded melt is denser than the host melt, the intrusion pounds at the base of the mush and emplaced as a horizontal layer. The occurrence of Rayleigh-Taylor instability leading to the rapid ascent of the intruded material through the mush was observed when the intruded melt was lighter than the host one and was also unrelated to the bulk density contrast. In the absence of density contrasts between the two melt phases, the intrusion may fluidize the host crystal network and slowly ascend through the mush. The effect of the viscosity contrast between the intruded and host materials was found to have a lesser importance on the architecture of intrusions in a mush. Analyzing the eruptive sequence of well documented eruptions involving an intrusion as the trigger shows a good agreement with our modeling results, highlighting the importance of specifically considering granular dynamics when evaluating magmas and mush physical processes. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164903
Appears in Collections: 气候变化与战略
There are no files associated with this item.
作者单位: Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, IFSTTAR, ISTerre, Grenoble, 38000, France; Department of Earth and Space Sciences, University of Washington, Box 351310, Seattle, WA 98195, United States
Recommended Citation:
Carrara A.,Burgisser A.,Bergantz G.W.. The architecture of intrusions in magmatic mush[J]. Earth and Planetary Science Letters,2020-01-01,549