气候变化领域集成服务门户(CCPortal): Petrogenesis of the Chakabeishan pegmatites, North Qaidam Terrane: Implications for Indosinian lithium mineralization in the northern Tibetan Plateau

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DOI	10.1016/j.lithos.2023.107025
	Petrogenesis of the Chakabeishan pegmatites, North Qaidam Terrane: Implications for Indosinian lithium mineralization in the northern Tibetan Plateau
	Liu, Jin-Heng; Wang, Qiang; Wang, Bing-Zhang; Li, Wu -Fu; Xu, Chuan-Bing; Li, Shan -Ping; Wang, Zi-Long; Hao, Lu-Lu; Song, Tai-Zhong; Wang, Chun-Tao; Zheng, Ying; Wang, Jin-Shou
发表日期	2023
ISSN	0024-4937
EISSN	1872-6143
卷号	440
英文摘要	Pegmatite-type Li deposit is a critical metal, which has been attracting extensive attention. However, its petrogenesis and Li-mineralization mechanism remain under debate. Recently, four types of Late Triassic (222-212 Ma) pegmatites are recognized in the Chakabeishan area of Markam-Yajiang-Karakoram (MYK) giant Li ore belt in northern Tibet: tourmaline-, garnet-. spodumene-, and lepidolite-bearing pegmatites. The tourmaline-bearing pegmatites show uniform Nd isotopic compositions (epsilon Nd(t) =-13.8 to-14.5), closed to those of the metasedimentary wall rocks (epsilon Nd(t) =-15.2 to-17.8), but significantly lower than those of the sur-rounding Middle Triassic (-244 Ma) syenogranites (epsilon Nd(t) =-4.7 to-5.5) that are typical I-type granites. These data, together with their higher Sm/Nd ratios, lower Y and LREE contents relative to the metasedimentary wall rocks, and lack of biotite, demonstrate that the tourmaline-bearing pegmatites were formed by the disequilibrium melting of the metasedimentary wall rocks involving water-absent muscovite dehydration melting with monazite in the residue. From the tourmaline-bearing pegmatites through the garnet-bearing pegmatites to the spodu- mene-and lepidolite-bearing pegmatites, gradually increasing whole-rock Li-Be contents as well as decreasing K/Rb ratios and increasing Cs contents in the K-feldspar and muscovite suggest that they were generated by continuous evolution of magmas similar to the tourmaline-bearing pegmatites. In addition, mineralogical observation and variable Nb and Ta contents in muscovite indicate that the Chakabeishan pegmatites experi-enced a three-stage evolution process, i.e., magmatic stage for tourmaline-and garnet-bearing pegmatites, coexisting aqueous and silicic magma to hydrothermal transition stage for spodumene-bearing pegmatites, and hydrothermal stage for lepidolite-bearing pegmatites. Taking into account regional geological constraints and our data, we suggest that the low-degree partial melting of clay-rich sedimentary rocks initially control the Li enrichment. The subsequent exsolution and accumulation of a fluid phase during magmatic evolution process occurred in the Li-poor and Li-rich pegmatites, respectively, which is responsible for the further Li mineralization.
关键词	Pegmatites Petrogenesis Li mineralization Chakabeishan Qinghai Tibet
英文关键词	LI ISOTOPE FRACTIONATION; RARE-METAL PEGMATITES; KUNLUN OROGENIC BELT; GRANITIC PEGMATITES; TECTONIC EVOLUTION; CONTINENTAL-CRUST; SYSTEM; MELTS; AREA; DISEQUILIBRIUM
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
WOS记录号	WOS:000926454300001
来源期刊	LITHOS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283401
作者单位	Chinese Academy of Sciences; Guangzhou Institute of Geochemistry, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS
推荐引用方式 GB/T 7714	Liu, Jin-Heng,Wang, Qiang,Wang, Bing-Zhang,et al. Petrogenesis of the Chakabeishan pegmatites, North Qaidam Terrane: Implications for Indosinian lithium mineralization in the northern Tibetan Plateau[J],2023,440.
APA	Liu, Jin-Heng.,Wang, Qiang.,Wang, Bing-Zhang.,Li, Wu -Fu.,Xu, Chuan-Bing.,...&Wang, Jin-Shou.(2023).Petrogenesis of the Chakabeishan pegmatites, North Qaidam Terrane: Implications for Indosinian lithium mineralization in the northern Tibetan Plateau.LITHOS,440.
MLA	Liu, Jin-Heng,et al."Petrogenesis of the Chakabeishan pegmatites, North Qaidam Terrane: Implications for Indosinian lithium mineralization in the northern Tibetan Plateau".LITHOS 440(2023).