Weak B-Type Olivine Fabric Induced by Fast Compaction of Crystal Mush in a Crustal Magma Reservoir

doi:10.1029/2018JB016728

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 中国科学院矿产资源研究重点实验室

	Weak B-Type Olivine Fabric Induced by Fast Compaction of Crystal Mush in a Crustal Magma Reservoir
	Yao, Zhuosen 1,2,3; Qin, Kezhang 1,2,4; Wang, Qin 5; Xue, Shengchao 1,6
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
	2019-04-01
卷号	124 期号:4 页码:3530-3556
关键词	lattice-preferred orientation olivine adcumulates compaction process seismic anisotropy crystal mush
ISSN号	2169-9313
DOI	10.1029/2018JB016728
英文摘要	Understanding the deformation mechanisms of olivine has been considered as the crucial factor in tracing the dynamic processes from seismic anisotropy. Due to extensive overprinting of deformation and alteration, natural examples of original magmatic fabric of olivine are scarce. In this study we selected one wehrlite and three dunite samples from a deep borehole in the Poyi mafic-ultramafic intrusion in the Tarim Craton. The fresh samples show adcumulate texture and plastic deformation of dry olivine (10ppm H2O). Thermobarometer calculations yield crystallization conditions at 200-400MPa and >1,124-1,275 degrees C. Olivine developed a B-type fabric characterized by a concentration of [001] axes parallel to the interpreted lineation and that of [010] axes normal to the interpreted foliation. Activation of [001] and [100] dislocations is confirmed by microstructural observations. Simulation of gravity-driven compaction process reveals extremely rapid compaction of kilometer-scale crystal mush in the Poyi magmatic system. During the early compaction with high porosity, crystallographic habit of olivine may produce shape-preferred orientation and the related B-type fabric. In the final stage of compaction and crystallization, the initial shape-preferred orientation was gradually overprinted, whereas the weak B-type fabric has remained with dislocation creep and dislocation-accommodated grain boundary sliding. Calculated seismic velocities of peridotite samples show low P and S wave anisotropies, with the fastest S wave polarization direction normal to the foliation. Hence, a mush-dominated ultramafic intrusion exhibits weak seismic anisotropy, which has potential to better understand seismic anisotropy in the transcrustal magmatic systems.
资助项目	NSFC project[41830430] ; NSFC project[41590623]
WOS关键词	LATTICE-PREFERRED ORIENTATION ; POYI ULTRAMAFIC INTRUSION ; CU SULFIDE MINERALIZATION ; NATURAL MANTLE MINERALS ; SEISMIC ANISOTROPY ; NW CHINA ; HIGH-TEMPERATURE ; DIFFUSION CREEP ; DYNAMIC RECRYSTALLIZATION ; COMPOSITIONAL CONVECTION
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	AMER GEOPHYSICAL UNION
WOS记录号	WOS:000468912000017
资助机构	NSFC project ; NSFC project ; NSFC project ; NSFC project ; NSFC project ; NSFC project ; NSFC project ; NSFC project
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/92133]
专题	地质与地球物理研究所_中国科学院矿产资源研究重点实验室
通讯作者	Yao, Zhuosen; Qin, Kezhang
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Mineral Resources, Beijing, Peoples R China 2.Univ Chinese Acad Sci, Beijing, Peoples R China 3.Carleton Univ, Dept Earth Sci, Ottawa, ON, Canada 4.Chinese Acad Sci, Inst Earth Sci, Beijing, Peoples R China 5.Nanjing Univ, Sch Earth Sci & Engn, State Key Lab Mineral Deposits Res, Nanjing, Jiangsu, Peoples R China 6.China Univ Geosci, State Key Lab Geol Proc & Mineral Resources, Beijing, Peoples R China
推荐引用方式 GB/T 7714	Yao, Zhuosen,Qin, Kezhang,Wang, Qin,et al. Weak B-Type Olivine Fabric Induced by Fast Compaction of Crystal Mush in a Crustal Magma Reservoir[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2019,124(4):3530-3556.
APA	Yao, Zhuosen,Qin, Kezhang,Wang, Qin,&Xue, Shengchao.(2019).Weak B-Type Olivine Fabric Induced by Fast Compaction of Crystal Mush in a Crustal Magma Reservoir.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,124(4),3530-3556.
MLA	Yao, Zhuosen,et al."Weak B-Type Olivine Fabric Induced by Fast Compaction of Crystal Mush in a Crustal Magma Reservoir".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 124.4(2019):3530-3556.