An Early Cretaceous W-Sn deposit and its implications in southeast coastal metallogenic belt: Constraints from U-Pb, Re -Os, Ar-Ar geochronology at the Feie'shan W-Sn deposit, SE China

摘要

The Feie'shan W-Sn deposit is in eastern Guangdong Province, which is a newly explored deposit in the southeastern coastal metallogenic belt. In order to constrain the age of mineralization in the Feie'shan W-Sn deposit, we collected molybdenites and hydrothermal biotite of the Feie'shan W-Sn deposit for dating. The tungsten mineralization is spatially associated with the biotite monzonitic granite porphyry. LA-MC-ICP-MS zircon U-Pb dating of the biotite monzonitic granite porphyry yielded a weighted mean Pb-206/U-238 age of 1392 +/- 1.7 Ma, which was interpreted as the emplacement age of the biotite monzonitic granite porphyry. The Re-Os model ages ranged from 1373 +/- 2.0 Ma to 146.1 +/- 2.1 Ma, with a weighted mean age of 140.6 +/- 1.9 Ma, and Ar-Ar isotopic analyses of hydrothermal biotite yield a plateau Ar-40/Ar-39 age of 135.1 +/- 0.8 Ma. These dates, obtained via three independent geochronological techniques, constrained the ore-forming age of the Feie'shan deposit and linked the genesis of the ore to the underlying biotite monzonitic granite porphyry. Combined with previous studies, it is suggested that there is a period at 144-132 Ma for W-Sn mineralization in the Southeastern Coastal Metallogenic Belt. The Feie'shan W-Sn deposit belongs to the 144-132 Ma metallogenic events in the SCMB, in a geodynamic setting of lithospheric extension. (C) 2016 Elsevier B.V. All rights reserved.