کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8914619 1640635 2017 20 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Landscape evolution of Lundy Island: challenging the proposed MIS 3 glaciation of SW Britain
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Landscape evolution of Lundy Island: challenging the proposed MIS 3 glaciation of SW Britain
چکیده انگلیسی
Lundy Island, in the Bristol Channel of south-west Britain, holds a pivotal place in understanding the extent and timing of Quaternary glaciations in southern Britain, in particular the timing, extent and dynamics of the Irish Sea Ice Stream during the Devensian glaciation. New geomorphological observations and revised interpretations of geomorphological and cosmogenic exposure data lead to the conclusion that Lundy was not covered by ice in the last (Devensian) glaciation. Geomorphological features are related to surface lowering by means of granite weathering under mainly periglacial and cool-temperate conditions. Previously reported cosmogenic ages are re-interpreted to reflect a dynamic equilibrium of cosmogenic nuclide production and surface lowering during a prolonged period of subaerial granite weathering. This re-evaluation of the geomorphology of Lundy Island challenges recently proposed interpretations of early glacial cover of Lundy (MIS 4-3) and for cold-based ice cover at the Last Glacial Maximum (MIS 2), and instead supports existing regional ice sheet reconstructions. This study demonstrates that a robust, coherent geomorphological framework is fundamentally important to support the validity of detailed geochronological and stratigraphic investigations.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Proceedings of the Geologists' Association - Volume 128, Issues 5–6, October 2017, Pages 722-741
نویسندگان
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