Fluids in deeply subducted continental crust: Petrology, mineral chemistry and fluid inclusion of UHP metamorphic veins from the Sulu orogen, eastern China

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	Fluids in deeply subducted continental crust: Petrology, mineral chemistry and fluid inclusion of UHP metamorphic veins from the Sulu orogen, eastern China
	Zhang, ZM (Zhang, Ze-Ming); Shen, K (Shen, Kun); Sun, WD (Sun, Wei-Dong); Liu, YS (Liu, Yong-Sheng); Liou, JG (Liou, J. G.); Shi, C (Shi, Cao); Wang, JL (Wang, Jin-Li)
刊名	GEOCHIMICA ET COSMOCHIMICA ACTA
	2008
卷号	72 期号:13 页码:3200-3228
ISSN号	0016-7037
英文摘要	The complex vein associations hosted in southern Sulu ultrahigh-pressure (UHP) eclogites contain quartz +/- omphacite (or jadeite) +/- kyanite +/- allanite +/- zoisite +/- rutile +/- garnet. These minerals have chemical compositions similar to those of host eclogites. Inclusions of polycrystalline quartz pseudomorphs after coesite were identified in vein allanite and garnet, and coesite inclusions were found in vein zircon. These facts suggest that the veins together with host eclogites have been subjected to synchronous UHP metamorphism. The vein minerals contain relatively high concentrations of rare earth elements (REE), high-field-strength elements (HFSE) and transition metal elements (TME). A kyanite-quartz vein has a whole-rock composition similar to adjacent UHP metamorphic granitic gneisses. Abundant primary multi-solid fluid inclusions trapped within UHP vein minerals contain complex daughter minerals of muscovite, calcite, anhydrite, magnetite, pyrite, apatite, celestite and liquid and gas phase of H(2)O with solids up to 30-70% of the inclusion volume. The presence of daughter minerals anhydrite and magnetite indicates the subduction fluids were oxidizing, and provides a possible interpretation for the high oxygen fugacity of subduction zone magmas. These characteristics imply that the UHP vein minerals were crystallized from supercritical silicate-rich aqueous fluids that were in equilibrium with peak-UHP minerals, and that the fluids in deeply subducted continental crust may contain very high concentrations of silicate as well as HREE, HFSE and TME. Such fluids might have resulted in major fractionation between Nb and Ta, i.e. the UHP fluids have subchondritic Nb/Ta values, whereas the host eclogites after extraction of the fluids have suprachondritic Nb/Ta values. Therefore, voluminous residual eclogites with high Nb/Ta ratios may be the complementary suprachondritic reservoir capable of balancing the subchondritic depleted mantle and continental crust reservoirs. (c) 2008 Elsevier Ltd. All rights reserved.
学科主题	变质岩岩石学
WOS关键词	SCIENTIFIC DRILLING PROJECT ; DORA-MAIRA MASSIF ; ULTRAHIGH-PRESSURE METAMORPHISM ; STABLE-ISOTOPE GEOCHEMISTRY ; COESITE-BEARING ECLOGITES ; SOUTH-CENTRAL CONNECTICUT ; DABIE-SHAN ; WESTERN ALPS ; EXPERIMENTAL CONSTRAINTS ; JIANGSU-PROVINCE
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000257175800009
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/38690]
专题	中国地质调查局
作者单位	Stanford Univ, Dept Geol & Environm Sci, Stanford, CA 94305 USA
推荐引用方式 GB/T 7714	Zhang, ZM ,Shen, K ,Sun, WD ,et al. Fluids in deeply subducted continental crust: Petrology, mineral chemistry and fluid inclusion of UHP metamorphic veins from the Sulu orogen, eastern China[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2008,72(13):3200-3228.
APA	Zhang, ZM .,Shen, K .,Sun, WD .,Liu, YS .,Liou, JG .,...&Wang, JL .(2008).Fluids in deeply subducted continental crust: Petrology, mineral chemistry and fluid inclusion of UHP metamorphic veins from the Sulu orogen, eastern China.GEOCHIMICA ET COSMOCHIMICA ACTA,72(13),3200-3228.
MLA	Zhang, ZM ,et al."Fluids in deeply subducted continental crust: Petrology, mineral chemistry and fluid inclusion of UHP metamorphic veins from the Sulu orogen, eastern China".GEOCHIMICA ET COSMOCHIMICA ACTA 72.13(2008):3200-3228.