Influence of Compaction Length on Radial Melt Segregation in Torsionally Deformed Partially Molten Rocks

doi:10.1029/2018GC007715

	Influence of Compaction Length on Radial Melt Segregation in Torsionally Deformed Partially Molten Rocks
	Qi, Chao 1,2; Kohlstedt, David L.1
刊名	GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
	2018-11-01
卷号	19 期号:11 页码:4400-4419
关键词	partial melts torsion melt segregation compaction length
ISSN号	1525-2027
DOI	10.1029/2018GC007715
英文摘要	To investigate the influence of compaction length on radial melt segregation during torsional shear deformation of partially molten rocks, experiments were performed on samples composed of olivine plus approximate to 7vol.% of either an albite, alkali basalt, or lithium silicate melt. These three melts cover a range of three orders of magnitude in viscosity, yielding samples that vary by approximately two orders of magnitude in compaction length. Samples were deformed in torsion at 1,473K and 300MPa in constant strain rate experiments to outer-radius shear strains of up to 14.3. Radial melt segregation occurred toward the axial center in all three types of samples that were sheared to (R) 4. At the same strain, samples with the largest compaction length exhibited the highest segregation rate, while samples with intermediate and smallest compaction lengths exhibited similar segregation rates. The experimental observations qualitatively agree with previously published results from two-phase flow theory for base-state melt segregation with anisotropic viscosity; specifically, the segregation rate for radial melt segregation increases with increasing compaction length. However, quantitatively, the segregation rate in experiments is smaller than the rate predicted by simulations for the same compaction length. This discrepancy may, for example, reflect the difference in rheological behavior between that observed in our experiments (non-Newtonian, dislocation-accommodated creep) and that incorporated into the numerical models (Newtonian, diffusion-accommodated creep). Our results thus provide a baseline for testing current and future models of two-phase flow, particularly as applied to understanding melt migration, segregation, and extraction from Earth's deeper interior.
资助项目	NSF[EAR-1520647]
WOS关键词	VISCOUS ANISOTROPY ; UPPER-MANTLE ; BAND FORMATION ; STRESS ; SHEAR ; PERMEABILITY ; DEFORMATION ; STRAIN ; CONSEQUENCES ; CONSTRAINTS
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	AMER GEOPHYSICAL UNION
WOS记录号	WOS:000452727800016
资助机构	NSF ; NSF ; NSF ; NSF ; NSF ; NSF ; NSF ; NSF
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/90279]
专题	中国科学院地质与地球物理研究所
通讯作者	Qi, Chao
作者单位	1.Univ Minnesota, Dept Earth Sci, Minneapolis, MN 55455 USA 2.Chinese Acad Sci, Inst Geol & Geophys, Beijing, Peoples R China
推荐引用方式 GB/T 7714	Qi, Chao,Kohlstedt, David L.. Influence of Compaction Length on Radial Melt Segregation in Torsionally Deformed Partially Molten Rocks[J]. GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS,2018,19(11):4400-4419.
APA	Qi, Chao,&Kohlstedt, David L..(2018).Influence of Compaction Length on Radial Melt Segregation in Torsionally Deformed Partially Molten Rocks.GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS,19(11),4400-4419.
MLA	Qi, Chao,et al."Influence of Compaction Length on Radial Melt Segregation in Torsionally Deformed Partially Molten Rocks".GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS 19.11(2018):4400-4419.