Sedimentary records of intense storms in Holocene barrier sequences, Maine, USA

摘要: Coastal-morphological, geophysical (ground-penetrating radar [GPR]), and sedimentological data document extreme storm events along the sandy barriers of Maine’s south–central (Hunnewell Flat Point barriers) southwestern (Saco Bay coastal compartments. The Hunnewell barrier contains four equally spaced buried scarps behind exposed scarp Blizzard 1978, a 100-year that eroded more than 100 m shoreline, causing extensive property loss. These dip 3–5j steeper normal beachface slope consist sands with 50% heavy minerals. minerals produce distinct subsurface reflections facilitate location supratidal parts mapping ancient poststorm shoreline positions. imaged likely formed within past 1.5–2.0 ka BP. consists prograded sequence overlain by laterally extensive, seaward-thinning layer freshwater peat capped aeolian sands. This stratigraphy suggests bog varied in size through time, contracting during overwash deposition expanding across washover sheets extended periods stability. main event accompanied planation wetland expansion may be linked to first historical New England, ‘‘Great Colonial Hurricane’’ 1635. Evidence near-modern mid-Holocene Saco includes units marsh ridges. Washovers interfinger saltmarsh ranges age from 4.5 BP modern. presence isolated ridges existing former tidal inlets reflects overtopping marshes high intertidal mudflats major storms. Radiocarbon ages indicate this process took place at different locations complex 3 1 D 2004 Elsevier B.V. All rights reserved.