Palynology of a terrestrial coal-bearing series across the Triassic/Jurassic boundary (Mecsek Mts, Hungary)

Abstract Palynology and palynofacies patterns of terrestrial Triassic/Jurassic boundary series of the South Hungarian Mecsek Mountains were studied in search of paleoenvironmental and vegetation changes and climatic signatures related to one of the major mass extinction events in Earth's history. Two selected and studied boreholes comprise continuous boundary sections and yield a diverse Late Rhaetian to Hettangian palynomorph assemblage. The most striking feature within the boundary interval is the series of cyclic short-term paleoenvironmental changes from fluvial/deltaic to swamp settings, as inferred from changes in palynomorph associations. However, increasing humidity is documented by a striking increase in trilete spores. These signatures display the response of terrestrial vegetation to regional and global environmental changes, although we found no clear evidence for a mass extinction as documented in the microflora

Structural, stratigraphic and sedimentological characterisation of a wide rift system : The Triassic rift system of the Central Atlantic Domain

Acknowledgments The authors would like to thank Shell E&P Rijswijk, for supporting this research. The authors are grateful to Pat Shannon, Catherine Baudon and Dominique Frizon de Lamotte for many discussions on rift processes. We would like to thank Steven Bergman for thorough comments on an early version of the paper, and Chris Morley and an anonymous reviewer for sharing ideas and references for writing a better paperPeer reviewedPostprin

Palynology of Triassic/Jurassic boundary key sections of the NW Tethyan Realm (Hungary and Slovakia)

Late Rhaetian/Hettangian microfloras of three depositional environments of the NW Tethyan realm have been studied: platform to basinal limestones of the Csővár section (N Hungary), shallow marine limestones and marls of the Tatra Mountains (N Slovakia) and terrestrial coal deposits of the Mecsek Mountains (S Hungary). The analysis of the palynological assemblages and palynofacies patterns builds the base for interpretation and comparison of the different depositional environments. Additionally, the sporomorph distribution and diversity are investigated with respect to environmental and climatic change within the Triassic/Jurassic boundary interval and the processes that may have caused these changes. A striking spore spike was detected in all depositional areas studied. Palynological investigations were accompanied by geochemical (stable isotope) and clay mineral analyses. The results of this integrated analysis point to a relatively sudden climatic change most probably caused by the volcanic activity of the Central Atlantic Magmatic Province (CAMP) associated with the onset of rifting of Pangaea during early Mesozoic times. The data obtained in the course of this thesis strongly support this interpretation and depositional series of Hungary and Slovakia proved to be key sections of the NW Tethyan realm