Multistratigraphic framework for continental Permian-Triassic boundary sections of northern Pangaea: key to a better understanding of the ecological consequences of the end-Permian crisis in the terrestrial realm

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Global processes at the Permian-Triassic boundary (PTB) caused the most severe biodiversity crisis known. In order to understand the triggering mechanisms of this mass extinction, multidisciplinary research on marine and terrestrial ecosystems is required. Within the marine realm a continuous fossil record enables high-resolution biostratigraphy, whereas time resolution is usually limited in the terrestrial realm due to discontinuous sedimentation. Thus, marine-terrestrial teleconnections are difficult to detect and therefore a highly controversial topic. Additionally, the majority of terrestrial PT sections of northern Pangaea are characterized by a hiatus at the critical PTB interval. Consequently, the few complete terrestrial PTB sections of central Europe, the Russian syncline, Siberia and N China are pivotal for deciphering the triggering processes of the end-Permian crisis. Accordingly, project aims are:A) The project aims to detect the position of the PTB in continental series using a multistratigraphic approach, and to correlate continental boundary sections with marine reference sections. Biostratigraphic investigations will focus on conchostracans. The current correlation schemes based on conchostracans need to be refined and calibrated by radiometric dating of pyroclastics as well as by integrating magneto- and chemostratigraphic (d13C-, d18O-, d34S-isotope) data. B) Furthermore, the project aims to elaborate biotic and abiotic data which are suited to characterize environmental changes in mixed marine-continental as well as in exclusively continental PTB sections within different geotectonic and climatic settings. The focus is set on palynofacies, documentation of facies architectures and palaeosoils as well as on isotopic and sediment geochemistry. The selected boundary sections form a transect from the marine stratotype section in Meishan (S China) via mixed marine-continental sections in S China to pure continental sections in N China. These boundary sections can be precisely correlated by marine fossils (conodonts, fusulinids) and radiometric data from pyroclastics. The transect is continued by continental PTB sections of the Russian syncline with a precise tetrapod- and magneto-/isotope-stratigraphic framework, and via Hungary and Poland to the continuous PTB section of the Central European basin. All these sections yield conchostracans in the critical PT transition (own preliminary work) which will enable precise marine-terrestrial correlations. Furthermore, the transect crosses different geotectonic units and different biomes. Thus, it will be possible to distinguish regional tectonical and regional climatic processes (effects of palaeolatitude) from global processes across the PTB. The data obtained will enable a critical analysis of existing hypotheses on the PTB event and its triggering mechanisms and finally, will contribute to the understanding of global processes causing major perturbation of ecosystems.