, Volume 58, Issue 7, pp 788-795,
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Late Paleozoic magmatism in South China: Oceanic subduction or intracontinental orogeny?

Abstract

A gneissic granite with an U-Pb age of 313±4 Ma was found in northeastern Fujian Province, South China. It is an S-type granite characterized by high K2O, Al2O3 and low SiO2, Na2O contents with high A/CNK ratio of 1.22 for the whole rock. Zircons with stubby morphology from the gneissic granite yield 206Pb/238U ages ranging from 326 to 301 Ma with a weighted average age of 313±4 Ma, and negative ɛHf(t) values from −8.35 to −1.74 with Hf model ages (T C DM) of 1.43 to 1.84 Ga. This S-type granite probably originated from late Paleoproterozoic crust in intracontinental orogeny. Integrated with previous results on paleogeographic reconstruction of South China, the nature of Paleozoic basins, Early Permian volcanism and U-Pb-Hf isotope of detrital zircons from the late Paleozoic to early Mesozoic sedimentary rocks, we suggest the occurrence of a late Paleozoic orogeny in the eastern Cathaysia Block, South China. This orogenic cycle includes Late Carboniferous (340–310 Ma) orogeny (compression) episode and Early Permian (287–270 Ma) post-orogenic or intraplate extension episode. Therefore, the late Paleozoic magmatism in the southeastern South China probably occurred during the intraplate orogeny rather than the arc-related process.

This article is published with open access at Springerlink.com