Tue, 24 Apr 2018 09:09:25 GMT
2005 Vol.30 No.4
Information about the protolith of the Huangtuling granulite in North Dabieshan has been unavailable. The complex evolution history of the rock and its host basement must be further discussed.LA - ICP - MS U - Pb dating was conducted on three textural domains in zircon from a high - temperature ,high - pressure felsic granulite in the Huangtuling area , North Dabieshan , Central China. The metamorphic growth - derived detrital zircon domain yields a 207 Pb/206 Pb age in the range of (2 493 ±54) -(2 500 ±180 ) Ma. The magmatic genesis - derived detrital zircon domain gives a 207 Pb/206 Pb age ranging from 2 628 Ma to 2 690 Ma , with an oldest 206 Pb/238 U age of (2 790 ±150) Ma. The metamorphic overgrowth or metamorphic recrystallization zircon domain yields a dicsordia with an upper intercept age of (2 044. 7 ±29. 3 ) Ma. Compositions of the mineral assemblage, major element geochemistry , and es-pecially the complex interior texture of the zircon suggest that the prololith of the felsic granulite is of sedimentary origin. Results show that the protolith material of the granulite came from a provenance with a complex thermal history , i. e. ~ 2. 8 Ga magmatism and ~ 2. 5 Ga metamorphism , and was deposited in a basin not earlier than 2. 5 Ga. The high - temperature and high - pressure granulite - facies metamorphic age was precisely constrained at (2. 04 ±0. 03 ) Ga , which indicates the granulite in Huangtuling area should be a relict of a Paleoproterozoic UHT (ultrahigh temperature ) metamorphosed slab.
Keywords:LA - ICP - MS U - Pb zircon dating , ages of protolith and granulite - facies metamorphism , provenance, felsic granulite , North Dabieshan.
Copyright Copyright 2013-2015 earth science online information network room website maintenance: XT
Address: China University of Geosciences "Earth Sciences" editorial department postcode: 430074
Phone: 027-67885075 Fax: 027-67885075