Baranyi, Viktória and Miller, Charlotte S. and Ruffell, Alastair and Hounslow, Mark W and Kürschner, Wolfram M. (2018) A continental record of the Carnian Pluvial Episode (CPE) from the Mercia Mudstone Group (UK) : palynology and climatic implications. Journal of the Geological Society. ISSN 0016-7649
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Abstract
The generally arid Late Triassic climate was interrupted by a wet phase during the mid-Carnian termed the Carnian Pluvial Episode (CPE). Quantitative palynological data from the Mercia Mudstone Group in the Wessex Basin (UK) reveal vegetation changes and palaeoclimate trends. Palynostratigraphy and bulk organic carbon isotope data allow correlation to other Carnian successions. The palynostratigraphy indicates that the Dunscombe Mudstone is Julian and the lowest part of the overlying Branscombe Mudstone Formation is Tuvalian. The Aulisporites acme characterizing the CPE in Tethyan successions and the Germanic Basin is missing in the UK. The quantitative palynological record suggests the predominance of xerophyte floral elements with a few horizons of increased hygrophytes. A humidity signal is not seen owing to the dry climate in central Pangea. Also, the signal might be masked by the overrepresentation of xerophyte regional pollen and the predominance of xerophyte hinterland flora. The bias towards regional pollen rain is enhanced by the potential increase in continental runoff related to seasonally humid conditions and differences in pollen production rates and transport mechanisms. The vegetation of British CPE successions suggests a more complex climate history during the Carnian, indicating that the CPE is not recognized by the same changes everywhere.