Ar-40/Ar-39 geochronology studies of rocks in eastern Himalaya syntaxis

	Ar-40/Ar-39 geochronology studies of rocks in eastern Himalaya syntaxis
	Gong JunFeng 1; Ji JanQing 1; Chen JianJun 1; Sang HaQing 2; Li BaoLong 1; Liu YiDuo 2; Han BaoFu 1
刊名	ACTA PETROLOGICA SINICA
	2008-10-01
卷号	24 期号:10 页码:2255-2272
关键词	Eastern Himalaya Namjagbarwa Ar-40/Ar-39 geochronology
ISSN号	1000-0569
文献子类	Article
英文摘要	Conventional Ar-40/Ar-39 geochronology studies have been done on 20 separate minerals in 13 samples which are from the Yarlung-Tsangpo River gorge, eastern Himalaya syntaxis. The Ar-40/Ar-39 geochronology data show that: (1) the values of (Ar-40/Ar-16), of all the minerals tested are close to 295. 5; (2) most plateau ages are accord with their respective inverse isochron ages within error range. Age statistics indicate that most Ar-40/Ar-39 ages are focused on 1.3Ma and 2.5Ma approximately, indicating that Namjagbarwa region has undergone two fast cooling-uplift events in middle Pliocene and early Pleistocene respectively. The samples are. collected from the northern to the southern parts of the gorge, they are from various altitude and belong to different tectonic units, and the petrogenesis and lithology of their protolith are different, but the Ar-40/Ar-39 ages of most minerals (including hornblende, biotite, muscovite and K-feldspar etc.) from various samples are similar, and the age of different minerals from a single sample are not distributed according to the value of the closure temperature to argon isotopic system. Therefore, it seems that the cooling rate of the rocks in Namjagbarwa region has being so fast since Pliocene that the cooling process to argon isotopic system of minerals from this area are apparently different from ones from slow cooling environment. The cooling rate of Namjagbarwa region has being 120 similar to 240 degrees C/Ma and so an uplift rate of 3. 4 similar to 6. 9 min/a since the latest 3Ma according to the data published in this paper.
WOS关键词	NAMCHE-BARWA SYNTAXIS ; DIFFUSION ; EXHUMATION ; PRESSURE ; AR-40
WOS研究方向	Geology
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000262520800007
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/69480]
专题	中国科学院地质与地球物理研究所
通讯作者	Gong JunFeng
作者单位	1.Peking Univ, Sch Earth & Space Sci, Lab Orogen Belts & Crustal Evoult, Beijing 100871, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithispher Evoult, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Gong JunFeng,Ji JanQing,Chen JianJun,et al. Ar-40/Ar-39 geochronology studies of rocks in eastern Himalaya syntaxis[J]. ACTA PETROLOGICA SINICA,2008,24(10):2255-2272.
APA	Gong JunFeng.,Ji JanQing.,Chen JianJun.,Sang HaQing.,Li BaoLong.,...&Han BaoFu.(2008).Ar-40/Ar-39 geochronology studies of rocks in eastern Himalaya syntaxis.ACTA PETROLOGICA SINICA,24(10),2255-2272.
MLA	Gong JunFeng,et al."Ar-40/Ar-39 geochronology studies of rocks in eastern Himalaya syntaxis".ACTA PETROLOGICA SINICA 24.10(2008):2255-2272.