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Sedimentology and luminescence ages of Glacial Lake Humber deposits in the central Vale of York |
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| Authors: | Della K Murton Steven M Pawley Julian B Murton |
| Institution: | a School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3YE, UK b Department of Geography, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK c Permafrost Laboratory, Department of Geography, University of Sussex, Brighton BN1 9QJ, UK |
| Abstract: | The sedimentary sequence through the Hemingbrough Formation exposed at two sites in the central part of the Vale of York, south of the Escrick moraine ridge, is described and used to reconstruct the palaeoenvironmental history of Glacial Lake Humber. Interbedded wave ripples and laminated silts and clays at both sites indicate that Lake Humber was characterised by fluctuating water levels, often no deeper than wave base. Optically stimulated luminescence ages of 21.0 ± 1.9, 21.9 ± 2.0, and 24.1 ± 2.2 kyr returned from two wave-rippled sandy beds within the glaciolacustrine sequence at Hemingbrough, c. 10 km south of the Escrick moraine ridge, provide the first direct chronological determination for the low-level phase of Lake Humber. As these beds are principally attributed to glacial meltwater emanating from the Vale of York ice lobe of the British Ice Sheet, when its margin was at or near the Escrick moraine ridge, this corroborates the interpretation that this ridge marks the LGM ice limit. |
| Keywords: | Lake Humber Glaciolacustrine Luminescence dating Last Glacial Maximum |
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