U-Pb zircon age of the foliated garnet-bearing granites in western Dabie Mountains, Central China

Citation
Hf. Zhang et al., U-Pb zircon age of the foliated garnet-bearing granites in western Dabie Mountains, Central China, CHIN SCI B, 46(19), 2001, pp. 1657-1660
Citations number
14
Categorie Soggetti
Multidisciplinary
Journal title
CHINESE SCIENCE BULLETIN
ISSN journal
10016538 → ACNP
Volume
46
Issue
19
Year of publication
2001
Pages
1657 - 1660
Database
ISI
SICI code
1001-6538(200110)46:19<1657:UZAOTF>2.0.ZU;2-F
Abstract
U-Pb zircon dating on two foliated garnet-bearing granite samples in the we stern Dabie ultrahigh-pressure (UHP) metamorphic unit yields concordant age s of (234 +/- 4) Ma and (227 +/- 5) Ma, respectively. These ages, following the UHP peak metamorphism, represent the magma emplacement ages for the fo liated garnet-bearing granites. This, for the first time, shows that there are the Triassic granites in the Dabie Mountains. The foliated garnet-beari ng granites resemble A-type granite in geochemical characteristics, indicat ing that they were formed in extensional geodynamic setting. The magma form ation reflects a reheating event in the Dabie orogenic belt and it enhances the transfer of tectonic regime from collision into extension and promotes the rapid exhumation into lower crust for the UHP metamorphic rocks.