Olivine fabrics and tectonic evolution of fore-arc mantles: A natural   perspective from the Songshugou dunite and harzburgite in the Qinling   orogenic belt, central China

doi:10.1002/2016GC006614

CORC > 北京大学 > 地球与空间科学学院

	Olivine fabrics and tectonic evolution of fore-arc mantles: A natural perspective from the Songshugou dunite and harzburgite in the Qinling orogenic belt, central China
	Cao, Yi ; Jung, Haemyeong ; Song, Shuguang
刊名	GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
	2017
关键词	LATTICE-PREFERRED ORIENTATION EARTHS UPPER-MANTLE DEEP UPPER-MANTLE SEISMIC ANISOTROPY LITHOSPHERIC MANTLE DEFORMATION EXPERIMENTS ORTHO-PYROXENE HIGH-PRESSURE SIMPLE SHEAR B-TYPE
DOI	10.1002/2016GC006614
英文摘要	To advance our understanding of the deformation characteristics, rheological behaviors, and tectonic evolution of the fore-arc lithospheric mantle, we analyzed mineral fabrics for a large spinel-bearing ultramafic massif in the Songshugou area in the Qinling orogenic belt, central China. In the spinel-poor coarse-grained dunite, stronger A/D-type and weaker C-type-like fabrics were found, whereas the spinel-rich coarse-grained dunite displayed a comparatively stronger B-type-like fabric. These olivine fabrics are high-T fabrics influenced by the presence of melt, in which B and C-type-like fabrics are inferred to be produced by melt-assisted grain boundary sliding during synkinematic high-T melt-rock reactions. In contrast, the spinel-poor porphyroclastic and fine-grained dunites present weak AG and B-type-like fabrics, respectively. Their olivine fabrics (low-T fabrics) are inferred to transform from A/D-type fabric in their coarse-grained counterparts possibly through mylonitization process assisted by low-T fluid-rock reactions, during which strain was accommodated by the fluid-enhanced dislocation slip and/or fluid-assisted grain boundary sliding processes. Combined with the tectonic results of our previous work, the high-T olivine fabrics are probably related to a young and warm fore-arc mantle where intense partial melting and high-T boninitic melt-rock reactions prevalently occurred, whereas the low-T olivine fabrics likely reflect the evolving tectonic settings through the cooling fore-arc mantle to a continental lower crust in a collisional orogeny where low-T fluid-rock reactions were pervasively activated. These low-T olivine fabrics imply that though cold, the fore-arc lithospheric mantle may be locally weak (similar to 20-30 MPa), allowing ductile deformation to occur at a geologically significant strain rate.; Mid-career Researcher Program through an NRF - MEST [NRF-2015R1A2A1A15052305]; BK21+ postdoctoral fellowship in Korea; Major State Basic Research Development Program [2015CB856105]; National Natural Science Foundation of China [41572040, 41372060]; SCI(E); ARTICLE; 3; 907-934; 18
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/474714]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Cao, Yi,Jung, Haemyeong,Song, Shuguang. Olivine fabrics and tectonic evolution of fore-arc mantles: A natural perspective from the Songshugou dunite and harzburgite in the Qinling orogenic belt, central China[J]. GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS,2017.
APA	Cao, Yi,Jung, Haemyeong,&Song, Shuguang.(2017).Olivine fabrics and tectonic evolution of fore-arc mantles: A natural perspective from the Songshugou dunite and harzburgite in the Qinling orogenic belt, central China.GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS.
MLA	Cao, Yi,et al."Olivine fabrics and tectonic evolution of fore-arc mantles: A natural perspective from the Songshugou dunite and harzburgite in the Qinling orogenic belt, central China".GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS (2017).