Palaeoenvironments, vegetation and climate from the Middle to Late Miocene Brassington Formation, UK

MATTHEW J. POUND; JAMES B. RIDING; JENNIFER M.K. OKEEFE; NOELIA NUÑEZ OTAÑO; MICHAEL LIM

Dublin

Conferencia; 10th European Palaeobotany and Palynology Conference; 2018

University College Dublin

Palaeoenvironments, vegetation and climate from the Middle to Late Miocene Brassington Formation, UKMatthew Pound1, James Riding2, Jennifer O´Keefe3, Noelia B. Nuñez Otaño4, Michael Lim11Northumbria University, Newcastle upon Tyne, United Kingdom, mathew.pound@northumbria.ac.uk2British Geological Survey, Keyworth, United Kingdom3Department of Earth and Space Sciences, Morehead State University, Morehead, KY, United States of America4Facultad de Ciencia y Tecnología (FCyT), Universidad Autónoma de Entre Ríos (UADER), Km 10,5, RP11, Oro Verde, 3100, ArgentinaThe Brassington Formation is the most extensive Miocene sedimentary succession onshore in the UK. Because of its unique position at the margin of NW Europe, the pollen, spores, fungal remains and macrofossils from this lithostratigraphical unit provide evidence on the development of environments and vegetation affected by North Atlantic currents and hypothesized atmospheric circulation changes that accompanied the Middle to Late Miocene climatic cooling. Previously, all occurrences of the Kenslow Member were assumed to be contemporaryP, however palynostratigraphy suggests that the uppermost Kenslow Member of the Brassington Formation is not coeval. Previously, all occurrences of the Kenslow Member were assumed to be contemporary. This new dating of the Brassington Formation now meansimplies that a sequence of fossiliferous horizons is present, rather than single layer. Using this the revised chronology, a new vegetation and climate record for the Atlantic margins of northwest Europe has been produced. We report that the Bees Nest Member, which underlies the Kenslow Member, is not barren as had been previously thought, and has produced a pollen assemblage. Overall, the palynology shows that the oldest pollen assemblage is from the more southern Bees Nest Pit, which represents a subtropical conifer-dominated forest of late Seravallian age (c. 12 Ma). A younger assemblage was observed from the more northern Kenslow Top Pit and indicates that a subtropical mixed forest was present during the early Tortonian (11.6?9 Ma).