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A fusuline fauna is described from the base of the Heshan Formation in the Penglaitan Section, the GSSP for the base Lopingian Series. This fauna falls within the Clarkina guangyuanensis and Clarkina transcaucasica conodont zones, indicating an early Wuchiapingian age. A new genus, Laibinella, is established to include those species that are morphologically similar to but phylogenetically independent of Palaeofusulina. In total, three species from two genera can be recognized in the studied material: Laibinella tobensis (Zhang), Laibinella ellipsoidalis gen. et sp. nov., and Lantschichites minima (Chen). The Laibinella tobensis Zone is established for the early Wuchiapingian. Based on morphology and biostratigraphy, we infer the evolutionary lineages of Dunbarula–Laibinella in the early Wuchiapingian, and Dunbarula–Nanlingella in the late Wuchiapingian. [ABSTRACT FROM AUTHOR]

The Global Stratotype Section and Point (GSSP) for the Permian-Triassic boundary was placed in Bed 27 of Meishan section D where the conodont species Hindeodus parvus first occurs. Bed 27 was usually considered comprising continuously-deposited, homogeneous silty limestone, with no depositional hiatus near the boundary. Detailed study on the boundary sequence revealed that a typical firmground characterized by Glossifungites ichnofacies developed about 2 cm below the Permian-Triassic boundary in Bed 27. Fossil content and lithology show apparent differences across the firmground crust. The abundance of the Permian bioclasts decreases significantly across the firmground, and is accompanied by a shift of dominating carbonate precipitation from calcite to dolomite. The firmground marked a rapid transgression at the very end of the Late Permian and significant shifts of sedimentary environment and paleoclimate. This transgressive submerging surface is also observed at the Huangzhishan section of the shallow-water carbonate platform facies in Zhejiang Province, the Jiangya section of the lower-slope to basinal-margin facies in Hunan Province, the Pingdingshan section of the basinal facies in Anhui Province of South China, as well as the Selong section in Tibet of the northern peri-Gondwana. The transgressive submerging surface marks the onset of a rapid global transgression at the latest Permian. [ABSTRACT FROM AUTHOR]

The late Paleozoic ice age was the longest icehouse of the Phanerozoic with complex terrestrial ecosystems and metazoan life. Simulations of late Paleozoic climate have confirmed the coupled relationship between Gondwanan ice dynamics and paleotropical climate on a multitude of timescales. However, it is still unclear how precipitation in the tropical zone would respond to changes in paleoclimate during the late Paleozoic ice age. Here, we present detailed sedimentological and biostratigraphic works on a late Carboniferous mixed carbonate-siliciclastic succession from the southeastern South China Block to explore sedimentary responses to paleoclimate variations. Conodont and fusulinid biostratigraphy indicate that the Outangdi succession formed during the middle to late Moscovian. Detailed facies analysis suggests that the succession was deposited on a carbonate ramp, episodically punctuated by braid delta sedimentation. Given the relatively stable tectonic setting and well-correlated, coeval siliciclastic deposition in the paleotropical peri-Paleotethys regions, the abrupt increase in siliciclastic influx in the late Moscovian resulted from an enhanced precipitation event associated with the glacial-to-interglacial shift. • An abrupt siliciclastic influx were recorded in tropical peri-Paleotethys regions in the late Moscovian • Water cycle would be enhanced in the paleotropical zone responding to the demise of glacial interval • Anomalous siliciclastic deposits could have been driven by climate factors. [ABSTRACT FROM AUTHOR]

Two negative carbon isotope excursions (3.5–6.5‰) across the Wuchiapingian-Changhsingian boundary (WCB) are observed globally (sections in China, Canada, and Iran); however, the causative mechanism of these excursions is debated. Here, high-resolution osmium isotope (187Os/188Os or Os i) chemostratigraphy of four globally correlated WCB sections (3 in China - Meishan, Shangsi and Lianyuan and 1 in Canada - Buchanan Lake) show two separate Os i excursions to less radiogenic compositions that are coincident with the carbon isotope shifts for two of the South China sections (Lianyuan, Meishan). In contrast, only a single Os i excursion to less radiogenic compositions, coinciding with the earliest Changhsingian carbon isotope shift, is observed for the Shangsi and Buchanan Lake sections. The Os i shift is interpreted to reflect increased unradiogenic Os input from basaltic magmatism in South China, possibly related to the Emeishan large igneous province (LIP). However, 187Os/188Os data suggest that only the earliest Changhsingian volcanism had global impact on both the ocean and atmosphere. The lack of any evidence for a biotic event associated with the WCB therefore may have been due to the more regional rather than global impact of volcanism during the latest Wuchiapingian. In contrast, during the earliest Changhsingian, volcanism was sufficient to cause a more global signal in the ocean osmium record, but was inadequate, or too prolonged, to drive any significant environmental change. Volcanism, however, may have provided the isotopically light carbon that drove the negative carbon isotope excursions across the WCB. [ABSTRACT FROM AUTHOR]