Polygenetic titanite records the composition of metamorphic fluids during the exhumation of ultrahigh-pressure metagranite in the Sulu orogen

doi:10.1111/jmg.12194

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 > 岩石圈演化国家重点实验室

	Polygenetic titanite records the composition of metamorphic fluids during the exhumation of ultrahigh-pressure metagranite in the Sulu orogen
	Chen, Y. -X.1; Zhou, K.1; Zheng, Y. -F.1; Gao, X. -Y.1; Yang, Y. H.2
刊名	JOURNAL OF METAMORPHIC GEOLOGY
	2016-08-01
卷号	34 期号:6 页码:573-594
关键词	metamorphic fluids subduction zone Titanite trace elements U-Pb dating
DOI	10.1111/jmg.12194
文献子类	Article
英文摘要	An integrated study of U-Pb ages and trace elements was carried out for titanite and zircon from ultrahigh-pressure (UHP) metagranites in the Sulu orogen, east-central China. The results provide constraints on the composition of metamorphic fluids during the exhumation of deeply subducted continental crust. Titanite has two domain types based on REE patterns and trace element variations, Ttn-I and Ttn-II respectively. These two domains show indistinguishable U-Pb ages of 232 +/- 14 to 220 +/- 8Ma, in general agreement with anatectic zircon U-Pb ages of 223 +/- 4 to 219 +/- 2Ma for the partial melting event during early exhumation. The Ttn-I domains have significantly higher REE, Th, Ta and Sr, and higher Th/U ratios than the Ttn-II domains, indicating that the two domains have grown from metamorphic fluids with different compositions. For the Ttn-I domains, Zr-in-titanite thermometry yields high temperatures of 773-851 degrees C at 2.5GPa, and petrographic observations reveal the presence of melt pseudomorphs. Thus, they are interpreted to have grown from hydrous melts in the early exhumation stage. In contrast, the Ttn-II domains were texturally equilibrated with amphibolite facies minerals such as biotite and plagioclase and contain inclusions of plagioclase and quartz. The Zr-in-titanite thermometry yields lower temperatures of 627-685 degrees C at 1.0GPa. In combination with their REE patterns, they are interpreted to have grown from aqueous solutions at amphibolite facies metamorphic conditions during further exhumation. The differences in Th and Sr contents are prominent between the Ttn-I and Ttn-II domains, signifying the compositional difference between the hydrous melts and aqueous solutions. Therefore, the polygenetic titanite in the UHP metamorphic rocks provides insights into the geochemical property of metamorphic fluids during the continental subduction-zone processes.
WOS关键词	U-PB AGES ; SUBDUCTION-ZONE METAMORPHISM ; TRACE-ELEMENT GEOCHEMISTRY ; NORTH CHINA CRATON ; LA-ICP-MS ; T-T PATH ; CONTINENTAL COLLISION ; EASTERN CHINA ; DABIE OROGEN ; RARE-EARTH
WOS研究方向	Geology
语种	英语
WOS记录号	WOS:000379933900004
资助机构	Chinese Ministry of Science and Technology(2015CB856106) ; Chinese Ministry of Science and Technology(2015CB856106) ; Natural Science Foundation of China(41473032) ; Natural Science Foundation of China(41473032) ; Youth Innovation Promotion Association of CAS(2014030) ; Youth Innovation Promotion Association of CAS(2014030) ; Fundamental Research Funds for the Central Universities(WK3410000010) ; Fundamental Research Funds for the Central Universities(WK3410000010) ; Chinese Ministry of Science and Technology(2015CB856106) ; Chinese Ministry of Science and Technology(2015CB856106) ; Natural Science Foundation of China(41473032) ; Natural Science Foundation of China(41473032) ; Youth Innovation Promotion Association of CAS(2014030) ; Youth Innovation Promotion Association of CAS(2014030) ; Fundamental Research Funds for the Central Universities(WK3410000010) ; Fundamental Research Funds for the Central Universities(WK3410000010)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/53390]
专题	地质与地球物理研究所_岩石圈演化国家重点实验室
作者单位	1.Univ Sci & Technol China, Sch Earth & Space Sci, CAS Key Lab Crust Mantle Mat & Environm, Hefei 230026, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Chen, Y. -X.,Zhou, K.,Zheng, Y. -F.,et al. Polygenetic titanite records the composition of metamorphic fluids during the exhumation of ultrahigh-pressure metagranite in the Sulu orogen[J]. JOURNAL OF METAMORPHIC GEOLOGY,2016,34(6):573-594.
APA	Chen, Y. -X.,Zhou, K.,Zheng, Y. -F.,Gao, X. -Y.,&Yang, Y. H..(2016).Polygenetic titanite records the composition of metamorphic fluids during the exhumation of ultrahigh-pressure metagranite in the Sulu orogen.JOURNAL OF METAMORPHIC GEOLOGY,34(6),573-594.
MLA	Chen, Y. -X.,et al."Polygenetic titanite records the composition of metamorphic fluids during the exhumation of ultrahigh-pressure metagranite in the Sulu orogen".JOURNAL OF METAMORPHIC GEOLOGY 34.6(2016):573-594.