Re‐assessment of the age and depositional origin of the Paviland Moraine, Gower, south Wales, UK

The Bristol Channel, including onshore areas, is critical for reconstructing Pleistocene glacial limits in southwest Britain. Debate about the precise regional southern limits of Devensian (Oxygen Isotope Stage ( OIS ) 2) and Anglian ( OIS 12) glaciations has recently been rekindled. The Paviland Mo...

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Published in:Boreas
Main Authors: Shakesby, Richard A., Hiemstra, John F., Kulessa, Bernd, Luckman, Adrian J.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2017
Subjects:
Online Access:http://dx.doi.org/10.1111/bor.12294
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spelling crwiley:10.1111/bor.12294 2024-06-02T08:08:21+00:00 Re‐assessment of the age and depositional origin of the Paviland Moraine, Gower, south Wales, UK Shakesby, Richard A. Hiemstra, John F. Kulessa, Bernd Luckman, Adrian J. 2017 http://dx.doi.org/10.1111/bor.12294 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fbor.12294 https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12294 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Boreas volume 47, issue 2, page 577-592 ISSN 0300-9483 1502-3885 journal-article 2017 crwiley https://doi.org/10.1111/bor.12294 2024-05-03T10:58:34Z The Bristol Channel, including onshore areas, is critical for reconstructing Pleistocene glacial limits in southwest Britain. Debate about the precise regional southern limits of Devensian (Oxygen Isotope Stage ( OIS ) 2) and Anglian ( OIS 12) glaciations has recently been rekindled. The Paviland Moraine (Llanddewi Formation), Gower, south Wales is conventionally regarded as Anglian in age. Its ‘old’ age has been based on reported highly weathered clasts, a subdued morphology and ‘field relationships’ to fossil beach sediments of now disputed age(s). Relatively little about its sedimentary characteristics has been previously published. This paper: (i) presents new sedimentological evidence including lithofacies analysis, XRF analysis and electrical resistivity tomography ( ERT ) of sediment cores and electrical resistivity of a tied 3D field grid; (ii) re‐assesses the proposed ‘old’ age; (iii) suggests a likely depositional origin; and (iv) discusses implications for regional glacial dynamics and future research priorities. The sediments comprise mostly dipping glacigenic diamict units containing mainly Welsh Coalfield erratics. The location and subdued moraine morphology are attributed to the hydrological influence of the underlying limestone, the local topography and ice‐sheet behaviour rather than to long‐term degradation. Moraine formation is attributed mainly to sediment gravity flows that coalesced to produce an ice‐frontal apron. Neither geochemical data nor clasts indicate prolonged subaerial weathering and in‐situ moraine sediments are restricted to a limestone plateau above and inland of fossil beach sediments. We recommend rejecting the view that the moraine represents the only recognized OIS 12 deposit in Wales and conclude that instead it marks the limit of relatively thin Last Glacial Maximum ( LGM ) ice in west Gower. This requires revision of the accepted view of a more restricted LGM limit in the area. We suggest that substrate hydrological conditions may be a more influential factor in moraine ... Article in Journal/Newspaper Ice Sheet Wiley Online Library Boreas 47 2 577 592
institution Open Polar
collection Wiley Online Library
op_collection_id crwiley
language English
description The Bristol Channel, including onshore areas, is critical for reconstructing Pleistocene glacial limits in southwest Britain. Debate about the precise regional southern limits of Devensian (Oxygen Isotope Stage ( OIS ) 2) and Anglian ( OIS 12) glaciations has recently been rekindled. The Paviland Moraine (Llanddewi Formation), Gower, south Wales is conventionally regarded as Anglian in age. Its ‘old’ age has been based on reported highly weathered clasts, a subdued morphology and ‘field relationships’ to fossil beach sediments of now disputed age(s). Relatively little about its sedimentary characteristics has been previously published. This paper: (i) presents new sedimentological evidence including lithofacies analysis, XRF analysis and electrical resistivity tomography ( ERT ) of sediment cores and electrical resistivity of a tied 3D field grid; (ii) re‐assesses the proposed ‘old’ age; (iii) suggests a likely depositional origin; and (iv) discusses implications for regional glacial dynamics and future research priorities. The sediments comprise mostly dipping glacigenic diamict units containing mainly Welsh Coalfield erratics. The location and subdued moraine morphology are attributed to the hydrological influence of the underlying limestone, the local topography and ice‐sheet behaviour rather than to long‐term degradation. Moraine formation is attributed mainly to sediment gravity flows that coalesced to produce an ice‐frontal apron. Neither geochemical data nor clasts indicate prolonged subaerial weathering and in‐situ moraine sediments are restricted to a limestone plateau above and inland of fossil beach sediments. We recommend rejecting the view that the moraine represents the only recognized OIS 12 deposit in Wales and conclude that instead it marks the limit of relatively thin Last Glacial Maximum ( LGM ) ice in west Gower. This requires revision of the accepted view of a more restricted LGM limit in the area. We suggest that substrate hydrological conditions may be a more influential factor in moraine ...
format Article in Journal/Newspaper
author Shakesby, Richard A.
Hiemstra, John F.
Kulessa, Bernd
Luckman, Adrian J.
spellingShingle Shakesby, Richard A.
Hiemstra, John F.
Kulessa, Bernd
Luckman, Adrian J.
Re‐assessment of the age and depositional origin of the Paviland Moraine, Gower, south Wales, UK
author_facet Shakesby, Richard A.
Hiemstra, John F.
Kulessa, Bernd
Luckman, Adrian J.
author_sort Shakesby, Richard A.
title Re‐assessment of the age and depositional origin of the Paviland Moraine, Gower, south Wales, UK
title_short Re‐assessment of the age and depositional origin of the Paviland Moraine, Gower, south Wales, UK
title_full Re‐assessment of the age and depositional origin of the Paviland Moraine, Gower, south Wales, UK
title_fullStr Re‐assessment of the age and depositional origin of the Paviland Moraine, Gower, south Wales, UK
title_full_unstemmed Re‐assessment of the age and depositional origin of the Paviland Moraine, Gower, south Wales, UK
title_sort re‐assessment of the age and depositional origin of the paviland moraine, gower, south wales, uk
publisher Wiley
publishDate 2017
url http://dx.doi.org/10.1111/bor.12294
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fbor.12294
https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12294
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op_source Boreas
volume 47, issue 2, page 577-592
ISSN 0300-9483 1502-3885
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op_doi https://doi.org/10.1111/bor.12294
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