TY - JOUR

T1 - Final deglaciation of the Malin Sea through meltwater release and calving events

AU - Tarlati, Serena

AU - Benetti, Sara

AU - Callard, Sarah Louise

AU - Ó Cofaigh, Colm

AU - Georgiopoulou, Aggeliki

AU - Edwards, R.

AU - Van Landeghem, Katrien

AU - Saher, Margot

AU - Chiverrell, Richard

AU - Fabel, Derek

AU - Moreton, Steven

AU - Morgan, Sally

AU - Clark, Chris

PY - 2020/11

Y1 - 2020/11

N2 - During the last glacial maximum, the British-Irish Ice Sheet (BIIS) extended to the shelf edge in the Malin Sea between Ireland and Scotland, delivering sediments to the Donegal Barra Fan (DBF). Analysis of well-preserved, glacially-derived sediment in the DBF provides new insights on the character of the BIIS final deglaciation and paleoenvironmental conditions at the Younger Dryas (YD). Chaotic/laminated muds, ice-rafted debris (IRD)-rich layers and laminated sand-mud couplets are interpreted as respectively mass transport deposits, plumites and turbidites of BIIS-transported sediments. Peaks in IRD, constrained by radiocarbon dating to after 18 ka cal. BP, indicate discrete intervals of iceberg calving during the last stages of deglaciation. Glacially-derived sedimentation on the slope occurred until ~16.9 ka cal. BP. This is interpreted as the last time the ice sheet was present onto the shelf, allowing glacial meltwater to reach the fan. Bioturbated and foraminifera-rich muds above glaciomarine sediments are interpreted as interglacial hemipelagites and contourites, with the presence of Zoophycos suggesting restoration of bottom currents at the transition between stadial and interstadial conditions. During the YD, Neogloboquadrina pachyderma sinistral abundances and an isolated peak in IRD indicate the temporary restoration of cold conditions and the presence of icebergs in the region.

AB - During the last glacial maximum, the British-Irish Ice Sheet (BIIS) extended to the shelf edge in the Malin Sea between Ireland and Scotland, delivering sediments to the Donegal Barra Fan (DBF). Analysis of well-preserved, glacially-derived sediment in the DBF provides new insights on the character of the BIIS final deglaciation and paleoenvironmental conditions at the Younger Dryas (YD). Chaotic/laminated muds, ice-rafted debris (IRD)-rich layers and laminated sand-mud couplets are interpreted as respectively mass transport deposits, plumites and turbidites of BIIS-transported sediments. Peaks in IRD, constrained by radiocarbon dating to after 18 ka cal. BP, indicate discrete intervals of iceberg calving during the last stages of deglaciation. Glacially-derived sedimentation on the slope occurred until ~16.9 ka cal. BP. This is interpreted as the last time the ice sheet was present onto the shelf, allowing glacial meltwater to reach the fan. Bioturbated and foraminifera-rich muds above glaciomarine sediments are interpreted as interglacial hemipelagites and contourites, with the presence of Zoophycos suggesting restoration of bottom currents at the transition between stadial and interstadial conditions. During the YD, Neogloboquadrina pachyderma sinistral abundances and an isolated peak in IRD indicate the temporary restoration of cold conditions and the presence of icebergs in the region.

U2 - 10.1144/sjg2019-010

DO - 10.1144/sjg2019-010

M3 - Article

VL - 56

SP - 117

EP - 133

JO - Scottish Journal of Geology

JF - Scottish Journal of Geology

SN - 0036-9276

IS - 2

ER -