Precambrian protoliths and Phanerozoic overprinting on the Wuyishan terrain (South China): New evidence from a combination of LA-ICPMS zircon and EMP monazite geochronology

摘要: Abstract Wuyishan is one of the most important terrains exposing Precambrian basement Cathaysia Block, South China. Conventionally, Paleoproterozoic and Neoproterozoic sequences have been proposed in this terrain, however, thermal histories affecting each unit within these remain unclear. We report here spot analysis 448 LA-ICPMS U-Pb zircon >1600 EMP Th-U-Pb monazite ages for twenty samples, including schist, gneiss, migmatite amphibolite, from different units basement. dating yield some concordant and/or Early Paleozoic age clusters with a wide spread Neoarchean to Mesoproterozoic inherited (except amphibolite), indicating formation Mayuan/Chencai core (887–827 Ma) peripheral two stages Late (746–731 Ma 681–660 Ma). The in-situ EMP analyses give consistent (440–426 Ma) inclusions various host minerals all but samples same locality that are Triassic (239–237 Ma). A large population interstitial monazites shows breakdown texture secondary range 376 Ma 358 Ma, conforming amphibolite (370 ± 5 Ma). few exhibit relict ∼540 Ma cores. conclude terrain dominated by related collisional continental rifting orogenies, respectively, while Badu Group Zhejiang as protolith. incorporating Cambrian detritus, has thoroughly metamorphosed during Silurian further affected regional fluid-aided metasomatism coeval basic magma, now represented amphibolites, around ∼370 Ma. results quite Yunkai massif where predominate, although Wuyi-Yunkai metamorphic belt often referred orogen Block.