Rb-Sr age of Gaik granite, Ladakh batholith, northwest Himalaya

Trivedi, J. R. ; Gopalan, K. ; Kisharma, Kewal ; Gupta, K. R. ; Choubey, V. M. (1982) Rb-Sr age of Gaik granite, Ladakh batholith, northwest Himalaya Proceedings of the Indian Academy of Sciences - Earth and Planetary Sciences, 91 (1). pp. 65-73. ISSN 0253-4126

PDF - Publisher Version

Official URL: http://www.ias.ac.in/j_archive/epsci/91/1/65-73/vi...

Related URL: http://dx.doi.org/10.1007/BF03028028


The Gaik Granite is a part of the Ladakh batholith outcropping between Gaik and Kiari in NW Himalaya. This is a pink porphyritic granite rich in biotite and poor in hornblende. Rb-Sr analyses have been made on six whole-rock samples of the Gaik Granite. Though the samples are poorly enriched in radiogenic Sr, they define a reliable isochron corresponding to an age of 235±13 (2σ) m.y. and initial 87Sr/86Sr ratio of 0.7081±0.0004 (2σ). Biotite, plagioclase and potash feldspar fractions separated from two of the samples have yielded a much younger mineral isochron at 30±1.5 m.y. indicating a nearly complete redistribution of Sr isotopes between mineral phases at a time much later than the primary emplacement of the granite. The present results show that at least some components of the Ladakh batholith are of Permo-Triassic age. These rocks were isotopically re-equilibrated on a mineral scale during Upper Oligocene in response to the Himalayan orogeny.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:Rb-Sr Age; Isochron; Ladakh Batholith; Hercynian; Permo-triassic; Granite
ID Code:13541
Deposited On:12 Nov 2010 15:23
Last Modified:16 May 2016 22:41

Repository Staff Only: item control page