DOI: 10.1016/j.epsl.2020.116162
论文题名: Transport of coexisting Ni-Cu sulfide liquid and silicate melt in partially molten peridotite
作者: Wang Z. ; Jin Z. ; Mungall J.E. ; Xiao X.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 536 语种: 英语
中文关键词: high P-T experiment
; liquid extraction
; lithosphere refertilization
; magmatic sulfide deposit
; synchrotron X-ray microtomography
英文关键词: Binary alloys
; Copper alloys
; Copper compounds
; Deposits
; Dihedral angle
; Drop breakup
; Extraction
; Grain boundaries
; Integrated circuit interconnects
; Liquids
; Olivine
; Silicates
; Structural geology
; Sulfur compounds
; Sulfur deposits
; Tomography
; X rays
; Hydrostatic conditions
; Laboratory experiments
; Liquid extraction
; lithosphere refertilization
; Magmatic sulfides
; Synchrotron X-ray microtomography
; Theoretical calculations
; X ray synchrotron microtomography
; Nickel compounds
; copper
; grain boundary
; nickel
; partial melting
; shear strain
; silicate melt
英文摘要: Transport of coexisting sulfide and silicate melts in partially molten peridotite contributes to the redistribution of chalcophile elements within the upper mantle as well as the genesis of magmatic Ni-Cu sulfide deposits, but has not been investigated systematically. Using laboratory experiments, theoretical calculations, and X-ray synchrotron microtomography, this study documents the topology and considers controls on the extraction of two immiscible liquids during partial melting of mantle peridotite. Under hydrostatic conditions, the measured dihedral angle at silicate melt-mineral-mineral junctions is 13.7–21.3°. Silicate melt is distributed along grain edges forming incompletely interconnected melt channels that disconnected by some dead ends at melt fractions ∼7–9 vol%. Application of theoretically predicted permeability (k∼10−14–10−16 m2) permits estimation of the extraction velocity of silicate melt of 0.7-11.1 μm/day within a single interconnected melt channel. In the absence of silicate melt, isolated sulfide droplets (3.77 vol%) show a sulfide-olivine-olivine dihedral angle of 91.5–101.3°. However, in the presence of silicate melt, sulfide droplets (average size ∼2.53 ± 2.14 μm, 1σ) are partially surrounded by silicate melt and stranded in triple junctions or melt pockets due to the limitation of the smallest dimension (0.3 μm) of melt channels. Thus, the extraction of sulfide liquid is highly restricted by these dead ends and the smallest dimension of melt channels during porous flow of silicate melt. In contrast, during large-strain shear deformation (strain ∼1.6–2.5), initially stranded sulfide droplets were elongated and extracted with silicate melt into liquid-rich sheets with a length of several hundred microns, constantly oriented at 14.3 ± 4.5° to the shear plane and antithetic to the shear direction. The angle is lower than that (18–30°) of those sheets containing sulfide liquid only, indicating that silicate melt dominates liquid-rich sheets. Driven by stress, silicate melt-dominated liquid-rich sheets open the appropriately oriented grain boundaries between silicate minerals, thus providing an efficient pathway for the extraction of sulfide liquid during deformation. When such sheet-like channels remain open, sulfide droplets (> millimeter-scale) can be potentially mobile through high strain domains of the upper mantle, contributing to the addition of chalcophile elements and the fertilization of the lithospheric mantle. © 2020 Elsevier B.V.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165339
Appears in Collections: 气候变化与战略
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作者单位: School of Earth Sciences, China University of Geosciences, Wuhan, 430074, China; State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, 430074, China; Department of Earth Sciences, Carleton University, 2115 Herzberg Laboratories, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada; Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, United States
Recommended Citation:
Wang Z.,Jin Z.,Mungall J.E.,et al. Transport of coexisting Ni-Cu sulfide liquid and silicate melt in partially molten peridotite[J]. Earth and Planetary Science Letters,2020-01-01,536