Latest Devonian to earliest Carboniferous conodont and carbon isotope stratigraphy of a shallow‐water sequence in South China

Abstract

AbstractTo improve regional and intercontinental correlation of the uppermost Devonian–lowermost Carboniferous, we examined the conodont faunas and carbon isotopic records of the Tangbagou Formation in the Qilinzhai section, southern Guizhou, South China. The Tangbagou Formation is a succession of mixed carbonate–siliciclastic rocks that accumulated on a shallow‐water platform under normal marine conditions. Seven conodont zones for shallow‐water biofacies in South China, theCl.gilwernensis–Cl.unicornisZone, thePo.spicatusZone, theSi.homosimplexZone, theSi.sinensisZone, theSi.eurylobataZone, thePs.multistriatusZone and thePo.co.porcatusZone in ascending order, are recognized in the Tangbagou Formation. Although apparently limited in its value for global correlation, this conodont zonation is more applicable to shallow‐water biofacies in South China. Carbonate samples have yielded carbon isotopic signatures consistent with those recorded in Euroamerica sections, in particular showing four distinct characteristics: (1) the peak values of Hangenberg Carbon Isotope Excursion (HICE) during the latest Devonian, (2) a minor positive shift (P1) in theSi.homosimplexZone during the early Tournaisian, (3) a second minor positive shift (P2) in theSi.sinensisZone and (4) the middle Tournaisian Carbon Isotope Excursion (TICE) in the middle part of the Tangbagou Formation. The similarity in peak values (~5.5‰) and magnitude of TICE for the Qilinzhai and Belgian sections indicates that the Euro‐asia δ13Ccarbtrends may reflect the changes in global mean ocean δ13CDIC, rather than having been overprinted by local carbon cycling. Integration of conodont biostratigraphy and δ13C stratigraphy provides a powerful tool for stratigraphic correlation. Copyright © 2015 John Wiley & Sons, Ltd.