Isochemical metamorphism origin of the newly discovered Baqing jadeitoid, eastern-central Tibet, China

doi:10.1111/jmg.12790

	Isochemical metamorphism origin of the newly discovered Baqing jadeitoid, eastern-central Tibet, China
	Jin, Xin 1,2,3; Whitney, Donna L.4; Zhang, Yu-Xiu 2; Blatchford, Hannah J.4,5; Zhang, Kai-Jun 2; Tsujimori, Tatsuki 6; Xiao, Yuan-Yuan 7; Liu, Hai-Yang 1; von der Handt, Anette 8; Yan, Li-Long 9; Liu, Yao 10; Lu, Lu 11; Li, Cong-Ying 1
	2024-07-11
发表期刊	JOURNAL OF METAMORPHIC GEOLOGY
ISSN	0263-4929
页码	29
通讯作者	Zhang, Yu-Xiu(zhangyuxiou@ucas.edu.cn) ; Zhang, Kai-Jun(kaijun@ucas.ac.cn) ; Xiao, Yuan-Yuan(yuanyuan.xiao@qdio.ac.cn)
摘要	The formation of most jadeitites and other jadeite-rich rocks (jadeitoids) during subduction is thought to occur by precipitation (P-type) or metasomatism (R-type) by infiltration of Na-Al-Si-rich aqueous fluids because of the compositional similarity of the rocks to inferred subduction fluids. Whether these rocks can form by isochemical metamorphism (I-type) during subduction is still hotly debated. A characteristic of I-type jadeitoid is that it exhibits a similar prograde metamorphic record as associated eclogite, in contrast to P- and R-type jadeitite and jadeitoids that are typically enclosed in serpentinite derived from the mantle wedge and either lack a prograde metamorphic history (R-type and P-type) or probably experience a prograde history (R-type) that is difficult to discern owing to the high variance of the jadeite-dominated assemblages and alteration by subduction fluids. The recently discovered Baqing (eastern-central Tibet) jadeitoid is enclosed by quartzo-feldspathic schist and has a peak metamorphic assemblage of almandine + jadeite/omphacite + phengite/paragonite + rutile + quartz, similar to eclogite. Abundant mineral inclusions in almandine, especially rutile inclusions with increasing Zr contents from the core to rim of almandine, provide an opportunity to further decode the jadeitoid-forming processes. In this study, pseudosections and Zr-in-rutile thermometry, together with conventional geothermobarometers, were employed to decipher the metamorphic history of Baqing jadeitoids. Two analysed Baqing jadeitoids exhibit a similar clockwise P-T path, starting from early metamorphic conditions of 5-7 kbar, 350-440 degrees C, to different peak conditions (27-29 kbar, 730-760 degrees C, or 20-23 kbar, 670-710 degrees C), followed by relatively consistent retrograde metamorphic conditions of 6-7 kbar, 530-600 degrees C. This result indicates a similar subduction history to the Baqing eclogite. In addition, the Baqing jadeitoids show similar geochemical characteristics to some Na-rich, K-depleted and Ca-depleted sedimentary rocks or plagiogranite. Therefore, we propose an isochemical genesis for the Baqing jadeitoid, rather than a metasomatic origin.
关键词	Baqing metamorphic complex isochemical metamorphism jadeitite jadeitoid prograde metamorphism Tibet Zr-in-rutile
DOI	10.1111/jmg.12790
收录类别	SCI
语种	英语
资助项目	National Natural Science Foundation of China[41472209] ; National Natural Science Foundation of China[42302048] ; National Natural Science Foundation of China[40802048] ; National Natural Science Foundation of China[42002218] ; Second Tibetan Plateau Scientific Expedition andResearch Program[2019QZKK0703] ; Fundamental ResearchFunds for the Central Universities[Y95401BXX2] ; Fundamental ResearchFunds for the Central Universities[E2E40409X2] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDA22050103] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDB42020303] ; Project of Exploration and Development ResearchInstitute, Northwest Oilfield Company,Sinopec[34400008-22-ZC0607-0044] ; College ofScience and Engineering; TaishanScholars Program ; China PostdoctoralScience Foundation[2021M703243] ; Shandong Postdoctoral Innovation Project[202103013] ; China Scholarship Council[201704910717] ; Natural ScienceYouth Foundation of Shandong Province[ZR2022QD039] ; Qingdao Postdoctoral Applied Research Program[E1KY12107N]
WOS研究方向	Geology
WOS类目	Geology
WOS记录号	WOS:001270031000001
出版者	WILEY
WOS关键词	MOTAGUA FAULT ZONE ; SERPENTINITE MELANGES ; DABIE MOUNTAINS ; NORTHERN TIBET ; HIGH-PRESSURE ; BEARING ; ROCKS ; ECLOGITES ; QUARTZITE ; FLUID
引用统计
文献类型	期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/186270
专题	深海极端环境与生命过程研究中心海洋地质与环境重点实验室
通讯作者	Zhang, Yu-Xiu; Zhang, Kai-Jun; Xiao, Yuan-Yuan
作者单位	1.Chinese Acad Sci, Ctr Deep Sea Res, Inst Oceanol, Qingdao, Peoples R China 2.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, 19A Yuquan Rd, Beijing 100049, Peoples R China 3.Zhejiang Ocean Univ, Dept Ocean Explorat & Technol, Zhoushan, Peoples R China 4.Univ Minnesota, Dept Earth & Environm Sci, Minneapolis, MN USA 5.Eastern Michigan Univ, Dept Geog & Geol, Ypsilanti, MI USA 6.Tohoku Univ, Ctr North East Asian Studies, Sendai, Miyagi, Japan 7.Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Qingdao, Peoples R China 8.Univ British Columbia, Dept Earth Ocean & Atmospher Sci, Vancouver, BC, Canada 9.Chinese Acad Geol Sci, Key Lab Deep Earth Dynam, Minist Nat Resources, Inst Geol, Beijing, Peoples R China 10.Chinese Acad Sci, Inst Oceanol, Publ Technol Serv Ctr, Qingdao, Peoples R China 11.China Univ Min & Technol, Key Lab Coalbed Methane Resources & Reservoir Form, Minist Educ China, Xuzhou, Peoples R China
第一作者单位	中国科学院海洋研究所
通讯作者单位	中国科学院海洋研究所
推荐引用方式 GB/T 7714	Jin, Xin,Whitney, Donna L.,Zhang, Yu-Xiu,et al. Isochemical metamorphism origin of the newly discovered Baqing jadeitoid, eastern-central Tibet, China[J]. JOURNAL OF METAMORPHIC GEOLOGY,2024:29.
APA	Jin, Xin.,Whitney, Donna L..,Zhang, Yu-Xiu.,Blatchford, Hannah J..,Zhang, Kai-Jun.,...&Li, Cong-Ying.(2024).Isochemical metamorphism origin of the newly discovered Baqing jadeitoid, eastern-central Tibet, China.JOURNAL OF METAMORPHIC GEOLOGY,29.
MLA	Jin, Xin,et al."Isochemical metamorphism origin of the newly discovered Baqing jadeitoid, eastern-central Tibet, China".JOURNAL OF METAMORPHIC GEOLOGY (2024):29.