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

二叠纪-三叠纪界线（PTB）的全球过程造成了已知的最严重的生物多样性危机。为了了解这种大规模灭绝的触发机制，需要对海洋和陆地生态系统进行多学科研究。在海洋领域内，连续的化石记录使高分辨率的生物地层学成为可能，而在陆地领域，由于不连续的沉积作用，时间分辨率通常是有限的。因此，海洋-陆地遥相关很难检测，因此是一个极具争议的话题。此外，大多数陆地PT部分的北方泛大陆的特点是在关键PTB间隔的中断。因此，中欧、俄罗斯向斜、西伯利亚和中国北部的少数几个完整的陆地PTB剖面是破译二叠纪末危机触发过程的关键。因此，项目的目标是：A）该项目旨在使用多地层方法探测PTB在大陆系列中的位置，并将大陆边界剖面与海洋参考剖面相关联。生物地层学研究将集中在叶肢介类。目前的相关方案的基础上，叶肢介需要完善和校准的火山碎屑岩的放射性测年，以及通过整合磁和化学地层（d13 C-，d18 O-，d34 S-同位素）数据。B）此外，该项目旨在详细说明生物和非生物数据，这些数据适合于描述不同大地构造和气候背景下海洋-大陆混合型以及纯大陆型PT B段的环境变化。重点放在孢粉相，相结构和古土壤的文件，以及同位素和沉积物地球化学。所选的边界剖面形成了一条从梅山海相层型剖面到华南海陆混合层型剖面再到华北纯大陆层型剖面的剖面。这些边界剖面可以通过海相化石（牙形刺、纺锤虫）和火山碎屑岩的放射性数据进行精确对比。该断面由俄罗斯向斜的大陆PTB部分延续，具有精确的四足动物和磁/同位素地层框架，并通过匈牙利和波兰延续到中欧盆地的连续PTB部分。所有这些部分产生叶肢介在关键的PT过渡（自己的初步工作），这将使精确的海洋-陆地的相关性。此外，样带跨越不同的大地构造单元和不同的生物群落。因此，它将有可能区分区域构造和区域气候过程（古纬度的影响）从全球过程跨PTB。所获得的数据将能够对PTB事件及其触发机制的现有假设进行批判性分析，最后，将有助于理解造成生态系统重大扰动的全球过程。

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.