TY - JOUR
T1 - Ice-sheet retreat from the continental shelf offshore of Northwest Ireland following the last glacial maximum: sedimentary facies and initial chronology
AU - Weilbach, Kasper
AU - O'Cofaigh, Colm
AU - Lloyd, Jerry
AU - Benetti, Sara
AU - Dunlop, Paul
AU - Howe, John
AU - Purcell, Catriona
PY - 2015/4/1
Y1 - 2015/4/1
N2 - The glacial history of North-West Ireland and the adjoining continental
shelf have been debated for over a century. The traditional
reconstruction of a British-Irish Ice Sheet (BIIS) in this region was
based predominantly on terrestrial evidence and showed an ice sheet that
did not extend beyond the present coastline of Britain and Ireland. This
traditional reconstruction of a relatively restricted ice sheet has been
replaced in the last decade by the reconstruction of a more dynamic ice
sheet that, during the Last Glacial Maximum (LGM), flowed onto the
continental shelf and extended to the NW-Irish shelf edge. High
resolution swath bathymetry and sub bottom profiler data along with
sedimentological, micropalaeontological and geochronological
investigations of sediment cores from the shelf offshore of NW Ireland
are being used to reconstruct the timing, extent and the nature of
retreat of the BIIS from the shelf following the LGM. A total of twenty
seven vibro-cores were collected during two research cruises on the
NW-Irish shelf in 2008 and 2014 on board the Irish and UK research
vessels the Celtic Explorer and RRS James Cook The cores were collected
in two east-west orientated transects across a series of arcuate
recessional moraines from the shelf edge to Donegal Bay. These moraines
record progressive stillstands of a lobate ice sheet margin during its
retreat from the shelf edge, although to date, there has been a lack of
direct dating control to constrain the timing and rate of ice retreat
across the shelf. Sedimentary descriptions of core facies and physical
properties, combined with taxonomic analysis of foraminifera will be
presented along with radiocarbon dates. This forms the first detailed
reconstruction of glacigenic sedimentation, depositional environments
and the timing of ice sheet retreat across the shelf offshore of NW
Ireland. The project is part of a larger EU funded research programme
GLANAM ('Glaciated North Atlantic Margins') which is investigating the
nature of glacially influenced sedimentation and ice sheet history
around the continental margins of the North Atlantic during the
Quaternary.
AB - The glacial history of North-West Ireland and the adjoining continental
shelf have been debated for over a century. The traditional
reconstruction of a British-Irish Ice Sheet (BIIS) in this region was
based predominantly on terrestrial evidence and showed an ice sheet that
did not extend beyond the present coastline of Britain and Ireland. This
traditional reconstruction of a relatively restricted ice sheet has been
replaced in the last decade by the reconstruction of a more dynamic ice
sheet that, during the Last Glacial Maximum (LGM), flowed onto the
continental shelf and extended to the NW-Irish shelf edge. High
resolution swath bathymetry and sub bottom profiler data along with
sedimentological, micropalaeontological and geochronological
investigations of sediment cores from the shelf offshore of NW Ireland
are being used to reconstruct the timing, extent and the nature of
retreat of the BIIS from the shelf following the LGM. A total of twenty
seven vibro-cores were collected during two research cruises on the
NW-Irish shelf in 2008 and 2014 on board the Irish and UK research
vessels the Celtic Explorer and RRS James Cook The cores were collected
in two east-west orientated transects across a series of arcuate
recessional moraines from the shelf edge to Donegal Bay. These moraines
record progressive stillstands of a lobate ice sheet margin during its
retreat from the shelf edge, although to date, there has been a lack of
direct dating control to constrain the timing and rate of ice retreat
across the shelf. Sedimentary descriptions of core facies and physical
properties, combined with taxonomic analysis of foraminifera will be
presented along with radiocarbon dates. This forms the first detailed
reconstruction of glacigenic sedimentation, depositional environments
and the timing of ice sheet retreat across the shelf offshore of NW
Ireland. The project is part of a larger EU funded research programme
GLANAM ('Glaciated North Atlantic Margins') which is investigating the
nature of glacially influenced sedimentation and ice sheet history
around the continental margins of the North Atlantic during the
Quaternary.
M3 - Article
VL - 17
SP - 1623
JO - EGU General Assembly 2015, held 12-17 April, 2015 in Vienna, Austria. id.1623
JF - EGU General Assembly 2015, held 12-17 April, 2015 in Vienna, Austria. id.1623
ER -