LA-ICPMS U-Pb zircon dating for felsic granulite, Huangtuling Area, North Dabieshan: Constraints on timing of its protolith and granulite-facies metamorphism, and thermal events in its provenance

Abstract

LA-ICPMS 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 yielded a 207Pb/ 206Pb age in the range of (2493±54)-(2500±180) Ma. The magmatic genesis-derived detrital zircon domain gave a 207Pb/ 206Pb age ranging from 2628 Ma to 2690 Ma, with an oldest 206Pb/ 238U age of (2790±150) Ma. The metamorphic overgrowth or metamorphic recrystallization zircon domain yielded a discordia with an upper intercept age of (2044.7±29.3) Ma. Compositions of the mineral assemblage, major element geochemistry, and an especially complex interior texture of zircon suggest that the protolith of the felsic granulite is of sedimentary origin. 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 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 the Paleoproterozoic UHT metamorphosed slab.