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The correlation between the fusulinid-based Tethyan and the conodont-based international timescales of the Permian System has become one of themost disputed issues among the Permian community during the past two decades. In this paper, we document a conodont fauna consisting of four species including Sweetognathus guizhouensis, Pseudohindeodus augustus, Hindeodus permicus and a new genus Meiognathus pustulus from the lower part of a large exotic limestone block at Hatahoko in the Nyukawa area, Gifu Prefecture, central Japan, which all suggest aKungurian age. The Kungurian age indicated by the conodonts is consistent with the age of the associated brachiopods, but conflicts with the Murgabian age indicated by the associated fusulinids including Cancellina nipponica, Neoschwagerina simplex, Neofusulinella praecursor etc. This co-occurrence of Kungurian conodonts and Murgabian fusulinids in central Japan suggests that previously unrecognized temporal distributions of some key fusulinid or conodont elements need to be clarified and that the intensively-disputed correlation problem between theKungurian containing theMurgabian fusulinids at the Luodian section in Guizhou, South China with the strata containing the ammonoid Waagenoceras in Oman and Sicily was caused by artificial conodont taxonomic discrepancies. The Luodian section in South China could serve as a key reference section for the correlation of the Kungurian Stage (late Early Permian) between the Tethyan and international timescales. [ABSTRACT FROM AUTHOR]

Abstract: To improve international stratigraphic correlation of the Lower Guadalupian–Lower Lopingian (Permian), we examined the stratigraphies of conodonts and organic carbon isotopes from pelagic chert sequences in the Gujo-hachiman section, Gifu, southwest Japan. Age-diagnostic conodonts, such as Jinogondolella nankingensis and Jinogondolella shannoni were found in the study section. The conodont stratigraphy in the Gujo-hachiman section was correlated with those in South China and West Texas, USA, to date the study section. From these correlations, it was found that the study section was from the upper Roadian (Lower Guadalupian) through Wuchiapingian (Lower Lopingian). Kerogen δ13C values were relatively high, around −29.0‰ in the upper Roadian–Wordian (Middle Guadalupian), decreasing over time to −29.4‰. A negative–positive swing in δ13C values of around 1‰ magnitude was recognized in the middle Capitanian (Upper Guadalupian). A similar negative–positive swing was also found in the Guadalupian–Lopingian (G–L) transitional zone in the Gujo-hachiman section, and is comparable to the isotopic change around the G–L boundary in the Penglaitan section, South China. Subsequently, δ13C values decreased to values below −30.0‰ above the G–L transitional zone, i.e., at the lower Wuchiapingian. Overall, δ13C values decreased from the lower Capitanian to the lower Wuchiapingian by over 1.4‰. A gradual increase in the δ13C values followed this long-term negative trend. These δ13C trends in the Gujo-hachiman section are comparable with time-equivalent δ13C records in different sections, suggesting that they record first-order variations in atmospheric δ13C. The high δ13C values during the upper Roadian–Wordian interval could reflect high primary productivity in the surface water of the pelagic Panthalassa Ocean, and imply global cooling. In contrast, the negative δ13C shift during the Capitanian–Wuchiapingian interval implies global warming. [Copyright &y& Elsevier]

Abstract: Guadalupian–Lopingian sedimentary rocks are widely distributed in accretionary complexes in Japan, but the Guadalupian–Lopingian boundary (G–LB) is not well documented from these pelagic sediments. To identify the G–LB and to better correlate an extinction event that occurred around the Guadalupian–Lopingian boundary, we examined the conodont biostratigraphy from a Permian pelagic chert sequence in the Gujo-hachiman section, Gifu, southwest Japan. Age-diagnostic conodonts, including Clarkina postbitteri postbitteri, were found in this section. The biostratigraphic occurrences of these age-diagnostic conodonts can pinpoint the “G–L transitional zone” in the Gujo-hachiman section by comparison with well-studied sections from south China, including the GSSP section. The transitional zone was recognized by the first occurrence horizons of both Clarkina postbitteri hongshuiensis and C. p. postbitteri. The G–LB has been placed at or above the first occurrence horizon of the radiolarians Albaillella yamakitai or Albaillella cavitata in previous studies from China and Japan. We detected the first occurrence horizon of A. yamakitai below the base of the “G–L transitional zone,” in the Upper Capitanian. The conodont biostratigraphy is consistent with the radiolarian biostratigraphy in this section, which can be correlated to relevant sections in China. [Copyright &y& Elsevier]