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| Callard, S. Louise; Cofaigh, Colm O.; Benetti, Sara; Chiverrell, Richard C.; Van Landeghem, Katrien J. J.; Saher, Margot H.; Gales, Jenny A.; Small, David; Clark, Chris D.; Stephen, J. Livingstone; Fabel, Derek; Moreton, Steven G.. |
| During the Last Glacial Maximum (LGM) the marine-terminating Barra Fan Ice Stream (BFIS), a major conduit of the British Irish Ice Sheet (BITS), drained much of western Scotland and northwest Ireland with ice streaming onto the continental shelf of the Malin Sea. The extent and retreat history of this ice stream across the shelf, until now, is not well known. In particular, geochronological constraints on the history of this ice stream have thus far been restricted to deep-sea cores or terrestrial cosmogenic nuclide dating onshore, with ages across the shelf absent. To understand the possible external forcing factors acting on this marine terminating ice stream during retreat, improved geochronological constraint on its deglaciation is necessary. Here, we... |
| Tipo: Text |
Palavras-chave: British-Irish Ice Sheet; Glacimarine; Last glacial maximum; Radiocarbon dating; Ice-sheet retreat; Grounding-zone wedges. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00504/61588/65891.pdf |
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| Finlayson, Andrew; Fabel, Derek; Bradwell, Tom; Sugden, David. |
| The boundary conditions that govern ice sheet dynamics can change significantly with the development of marine margins. This paper uses the glacial landscape in western Scotland to reconstruct changes in the British-Irish Ice Sheet that accompanied the growth and decay of a marine sector over the Malin Shelf. Ice advanced from a restricted mountain ice sheet with tidewater margins after similar to 35 ka BP, and reached the continental shelf in similar to 7 ka (average rate of similar to 30 m a(-1)). Early ice flow had been directed through north-south, geologically controlled, over-deepened fjords that were carved during previous 'restricted' glaciations. This flow regime was abandoned with development of the Malin Shelf ice sheet sector; ice flow... |
| Tipo: Text |
Palavras-chave: British-Irish Ice Sheet; Glacial landscape; Palaeoglaciology; Marine terminating; Malin Shelf. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00291/40240/83001.pdf |
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| Small, David; Benetti, Sara; Dove, Dayton; Ballantyne, Colin K.; Fabel, Derek; Clark, Chris D.; Gheorghiu, Delia M.; Newall, Jennifer; Xu, Sheng. |
| Understanding how marine-based ice streams operated during episodes of deglaciation requires geochronological data that constrain both timing of deglaciation and changes in their flow behaviour, such as that from unconstrained ice streaming to topographically restricted flow. We present seventeen new Be-10 exposure ages from glacial boulders and bedrock at sites in western Scotland within the area drained by the Hebrides Ice Stream, a marine-based ice stream that drained a large proportion of the former British-Irish Ice Sheet. Exposure ages from Tiree constrain deglaciation of a topographic high within the central zone of the ice stream, from which convergent flowsets were produced during ice streaming. These ages thus constrain thinning of the Hebrides... |
| Tipo: Text |
Palavras-chave: Exposure dating; Marine ice stream; British-Irish ice sheet; Deglaciation. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53148/55337.pdf |
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| Ballantyne, Colin K.; Fabel, Derek; Gheorghiu, Delia; Rodes, Angel; Shanks, Richard; Xu, Sheng. |
| The St Kilda archipelago lies similar to 65 km west of the Outer Hebrides and similar to 60 km east of the Atlantic shelf break, and represents a key site for testing the assertion that during the Last Local Glacial Maximum (LLGM; c. 27 ka) the British-Irish Ice Sheet (BIIS) extended to near the shelf edge in all sectors. Two consistent cosmogenic Cl-36 exposure ages averaging (>=) 81.6 +/- 7.8 kafor perched bouldersat 290 maltitudedemonstrate that the last ice sheet failed tooverrun high ground on the largest island, Hirta. Cl-36 and Be-10 exposure ages for glacially emplaced boulders on low ground indicate deposition by small, locally nourished glaciers that last occupied a north-facing valley (Gleann Mor) at c. 30.9 +/- 3.2 ka, prior to extension of... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53143/55405.pdf |
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| Small, David; Clark, Chris D.; Chiverrell, Richard C.; Smedley, Rachel K.; Bateman, Mark D.; Duller, Geoff A. T.; Ely, Jeremy C.; Fabel, Derek; Medialdea, Alicia; Moreton, Steven G.. |
| This contribution documents the process of assessing the quality of data within a compilation of legacy geochronological data relating to the last British-Irish Ice Sheet, a task undertaken as part of a larger community-based project (BRITICE-CHRONO) that aims to improve understanding of the ice sheet's deglacial evolution. As accurate reconstructions depend on the quality of the available data, some form of assessment is needed of the reliability and suitability of each given age(s) in our dataset. We outline the background considerations that informed the quality assurance procedures devised given our specific research question. We describe criteria that have been used to make an objective assessment of the likelihood that an age is influenced by the... |
| Tipo: Text |
Palavras-chave: British-Irish Ice Sheet; Deglaciation; Geochronology; Data compilations; Quality assurance; Bayesian. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00504/61598/65865.pdf |
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