Two types of garnets in the Cenozoic granites from the Himayalan;Orogenic Belt: Geochemical characteristics and implications for crustal;anatexis

	Two types of garnets in the Cenozoic granites from the Himayalan;Orogenic Belt: Geochemical characteristics and implications for crustal;anatexis
	Gao LiE 5; Zeng LingSen ; Shi WeiGang ; Chen Zhenyu ; Hu MingYue ; Sun DongYang
刊名	ACTA PETROLOGICA SINICA
	2012
卷号	28 期号:9 页码:2963-2980
关键词	Leucogranite Garnet Trace element geochemistry Crustal anatexis Himalayan Orogenic Belt
ISSN号	022HC
英文摘要	In the Himalayan Orogenic Belt, garnets occur as one of the key constituent phases in metapelites as well as one of the important accessory phases in leucogranites or leucosomes in migmatites. They have preserved critical information with regard to the geochemical nature of crustal anatexis and could yield important insights on the physical and chemical processes of middle to lower crustal rocks in large collisional orogenic belts. Along the Himalayan orogenic belt, two types of garnets, magmatic and metamorphic, occur in Cenozoic granitic rocks (leucogranite and leucosome). Magmatic garnets are euhedral to subhedral and commonly free of inclusions, whereas those derived from the source rocks show embayment texture and have been subjected to various degrees of melt-garnet reactions. Chemical analyses show that magmatic garnets are characterized by (1) typical oscillatory growth zonation; (2) enrichment in HREE, but highly depletion in LREE, and rim-ward decreases in Hf, Y and HREE; (3) pronounced negative Eu anomalies; (4) elevated Mn and Zn concentrations relative to those in metamorphic garnets derived from the source rocks. Petrographic and geochemical characteristics of garnets from leucogranites suggests that a large portion of Zn was incorporated in garnet and fractional crystallization of plagioclase and zircon is the major factor that regulate the magnitude of negative Eu anomalies and the abundance and rim-ward decreasing pattern of Hf, Y and HREE in magmatic garnet. Our data indicate that fine-scale chemical variations in magmatic garnet could serve as another important revenue to unravel the magmatic processes during the crystallization of leucogranitic melts.
学科主题	火成岩岩石学
WOS关键词	TIBET FORMATION MECHANISM ; YARDOI GNEISS DOME ; WOMAN PIUTE RANGE ; SOUTHERN TIBET ; HIMALAYAN LEUKOGRANITES ; GEOLOGICAL IMPLICATIONS ; TECTONIC IMPLICATIONS ; ZIRCON GEOCHRONOLOGY ; TETHYAN HIMALAYA ; MAGMATIC ; GARNET
WOS研究方向	Geology
语种	中文
WOS记录号	WOS:000309947500023
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39840]
专题	中国地质科学院地质研究所
作者单位	1.Chinese Acad Geol Sci, Inst Geol, State Key Lab Continental Tecton & Dynam, Beijing 100037, Peoples R China. 2.Shaanxi Bur Geol & Mineral Resources Dev, Inst Reg Geol & Mineral Resource, Xianyang 712000, Peoples R China. 3.Chinese Acad Geol Sci, Inst Mineral Resources, Beijing 100037, Peoples R China. 4.Chinese Acad Geol Sci, Natl Res Ctr Geoanal, Beijing 100037, Peoples R China. 5.中国地质科学院地质研究所
推荐引用方式 GB/T 7714	Gao LiE,Zeng LingSen,Shi WeiGang,et al. Two types of garnets in the Cenozoic granites from the Himayalan;Orogenic Belt: Geochemical characteristics and implications for crustal;anatexis[J]. ACTA PETROLOGICA SINICA,2012,28(9):2963-2980.
APA	Gao LiE,Zeng LingSen,Shi WeiGang,Chen Zhenyu,Hu MingYue,&Sun DongYang.(2012).Two types of garnets in the Cenozoic granites from the Himayalan;Orogenic Belt: Geochemical characteristics and implications for crustal;anatexis.ACTA PETROLOGICA SINICA,28(9),2963-2980.
MLA	Gao LiE,et al."Two types of garnets in the Cenozoic granites from the Himayalan;Orogenic Belt: Geochemical characteristics and implications for crustal;anatexis".ACTA PETROLOGICA SINICA 28.9(2012):2963-2980.