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The Penglaitan section, as the Global Stratotype Section for the Guadalupian-Lopingian boundary (GLB), displays continuous deposition with a complete succession of pelagic conodont zones across the GLB. However, there is no reliable radiometric age from the Penglaitan section itself to constrain the GLB. Here, we report SIMS zircon U-Pb ages from two bentonite layers (Bed 7c) in the Penglaitan Global Stratotype Section near the GLB. The sample PL-62-1 yields a weighted mean 238U/206Pb age of 257.1 ± 2.2 Ma, and the sample PL-62-2 yields a weighted mean 206Pb/238U age of 257.0 ± 4.2 Ma. Therefore, we consider 257.0-257.1Ma as the age of deposition of Bed 7c (the end of the C. postbitteri postbitteri conodont Zone, ca. 86 cm above the GLB), and, considering the depositional rate of chert, we suggest 258.6Ma as the age of the GLB. [ABSTRACT FROM AUTHOR]

Highlights: [•] The Huangling massif has an asymmetric domal structures and deformation styles related to its uplifting. [•] Cooling history reveals the Huangling massif underwent distinct uplifting between 160Ma and 110Ma. [•] Structural geology and geochronology improve the knowledge of the Late Mesozoic tectonics of Eastern China. [Copyright &y& Elsevier]

Highlights: [•] Geobarometry work shows that the studied massif intrudes into shallow crustal depth. [•] Gravity modeling shows that the massif vertically or sub-vertically intruded. [•] NE–SW tension gashes as magma conduits imply a syn-emplacement NW–SE regional extension. [Copyright &y& Elsevier]

Abstract: The Xuefengshan Belt, characterized by large-scale fold and thrust structures and widespread granites, is a key area to decipher the tectonic evolution of the South China block. In this belt, two magmatic episodes are recorded by Early Paleozoic and Early Mesozoic granites. In this paper, we carried out precise SIMS zircon U and in situ Lues measurements on these granitic plutons. Our study indicates that the Early Paleozoic and the Early Mesozoic granites are late-orogenic products of the Early Paleozoic orogen and the Middle Triassic Xuefengshan orogen, respectively. In the Xuefengshan Belt, the Early Paleozoic event is poorly registered, since this area corresponds to the outer zone of the early Paleozoic orogen. The Silurian–Early Devonian granites are late-orogenic plutons emplaced after the main tectonic and metamorphic stage in the Wuyi–Baiyun–Yunkai belt, coeval with a widespread, subsequent extensional event in eastern and southern South China. On the other hand, Triassic granites are formed in an intracontinental environment with weakly to strongly peraluminous signatures. Zircon Uresented here, associated with a summary of newly acquired data in the same region, suggest that the emplacement of anatectic granites occurred around 225–215Ma, not in a rather wide range of ca. 245–200Ma. In situ zircon εHf(t) values indicate a crust-derived source without a mantle-derived input for the two generations of granites. Combining our data with recent studies, we infer that the central area of the South China block has experienced two tectonothermal events: the Early Paleozoic magmatism developed as a result of the collapse of the Early Paleozoic orogen, while these Early Mesozoic granites can be the late-orogenic products of the intracontinental Xuefengshan orogen, most likely manifesting the far field effect by the subduction of the Paleo-Pacific ocean plate at the southeastern margin of the South China block. [Copyright &y& Elsevier]