A critical review and re-investigation of the Pleistocene deposits between Cranfield Point and Kilkeel, Northern Ireland: implications for regional sea-level models and glacial reconstructions of the northern Irish Sea basin

Merritt, Jon W.; Roberson, Sam; Cooper, Mark R.. 2018 A critical review and re-investigation of the Pleistocene deposits between Cranfield Point and Kilkeel, Northern Ireland: implications for regional sea-level models and glacial reconstructions of the northern Irish Sea basin. Proceedings of the Geologists' Association, 129 (5). 583-609. https://doi.org/10.1016/j.pgeola.2018.04.001

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Official URL: https://doi.org/10.1016/j.pgeola.2018.04.001

Abstract/Summary

The coastline of County Down includes sites that are pivotal to understanding the history of the last glaciation of the northern Irish Sea Basin in relation to relative sea level and regional glacial readvances. The cliff sections display evidence that has been used to underpin controversial models of glaciomarine sedimentation in isostatically-depressed basins followed by emergent marine and littoral environments. They also provide crucial evidence claimed to constrain millennial-scale ice sheet oscillations associated with uniquely large and rapid sea-level fluctuations. This paper reviews previous work and reports new findings that generally supports the ‘terresrrial’ model of glaciation, involving subglacial accretion and deformation of sediment beneath grounded ice. Deep troughs were incised into the till sheet during a post Late Glacial Maximum draw-down of ice into the Irish Sea Basin. Ice retreat was accompanied by glaciomarine accretion of mud in the troughs during a period of high relative sea level. The trough-fills were over-ridden, compacted, deformed and truncated during a glacial re-advance that is correlated with the Clogher Head Readvance. Grounding-line retreat accompanied by rapid subaqueous ice-proximal sedimentation preserved a widespread subglacial stone pavement. Raised beach gravels cap the sequence. The evidence supports an uninterrupted fall in relative sea level from c. 30 m that is consistent with sea level curves predicted by current glacio-isostatic adjustment modelling. Critical evidence previously cited in support of subaerial dissection of the troughs, and hence rapid fall and rise in relative sea level prior to the deposition of the glaciomarine muds, is not justified.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1016/j.pgeola.2018.04.001
ISSN:	0016-7878
Additional Keywords:	Irish Sea ice, glaciomarine, Northern Ireland glacial history, stone pavement, sea level change, Clogher Head Readvance.
NORA Subject Terms:	Earth Sciences
Date made live:	15 Oct 2018 12:37 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/521184

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1016/j.pgeola.2018.04.001

ISSN:

0016-7878

Additional Keywords:

Irish Sea ice, glaciomarine, Northern Ireland glacial history, stone pavement, sea level change, Clogher Head Readvance.

NORA Subject Terms:

Earth Sciences

Date made live:

15 Oct 2018 12:37 +0 (UTC)