Implications of 36Cl exposure ages from Skye, northwest Scotland for the timing of ice stream deglaciation and deglacial ice dynamics
| Type | Article | ||||||||||||||||
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| Date | 2016-10 | ||||||||||||||||
| Language | English | ||||||||||||||||
| Author(s) | Small David1, 7, Rinterknecht Vincent1, 2, Austin William E. N.1, 3, Bates Richard1, Benn Douglas I.1, Scourse James D.4, Bourles Didier L.5, Hibbert Fiona D.6 | ||||||||||||||||
| Affiliation(s) | 1 : Univ St Andrews, Sch Geog & Geosci, St Andrews KY16 9AL, Fife, Scotland. 2 : Univ Paris 1 Pantheon Sorbonne, CNRS, Lab Geog Phys, F-92195 Meudon, France. 3 : Scottish Assoc Marine Sci, Scottish Marine Inst, Oban PA37 1QA, Argyll, Scotland. 4 : Bangor Univ, Sch Ocean Sci, Menai Bridge LL59 5AB, Anglesey, Wales. 5 : Aix Marseille Univ, CNRS IRD Coll France, UM CEREGE 34, Technopole Environm Arbois Mediterranee,BP8, F-13545 Aix En Provence, France. 6 : Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT 2601, Australia. 7 : Univ Glasgow, Dept Geog & Earth Sci, Glasgow G12 8QQ, Lanark, Scotland. |
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| Source | Quaternary Science Reviews (0277-3791) (Pergamon-elsevier Science Ltd), 2016-10 , Vol. 150 , P. 130-145 | ||||||||||||||||
| DOI | 10.1016/j.quascirev.2016.08.028 | ||||||||||||||||
| WOS© Times Cited | 14 | ||||||||||||||||
| Keyword(s) | Deglaciation, Scotland, Cosmogenic exposure ages, Chlorine-36 | ||||||||||||||||
| Abstract | Geochronological constraints on the deglaciation of former marine based ice streams provide information on the rates and modes by which marine based ice sheets have responded to external forcing factors such as climate change. This paper presents new 36Cl cosmic ray exposure dating from boulders located on two moraines (Glen Brittle and Loch Scavaig) in southern Skye, northwest Scotland. Ages from the Glen Brittle moraines constrain deglaciation of a major marine terminating ice stream, the Barra-Donegal Ice Stream that drained the former British-Irish Ice Sheet, depending on choice of production method and scaling model this occurred 19.9 ± 1.5–17.6 ± 1.3 ka ago. We compare this timing of deglaciation to existing geochronological data and changes in a variety of potential forcing factors constrained through proxy records and numerical models to determine what deglaciation age is most consistent with existing evidence. Another small section of moraine, the Scavaig moraine, is traced offshore through multibeam swath-bathymetry and interpreted as delimiting a later stillstand/readvance stage following ice stream deglaciation. Additional cosmic ray exposure dating from the onshore portion of this moraine indicate that it was deposited 16.3 ± 1.3–15.2 ± 0.9 ka ago. When calculated using the most up-to-date scaling scheme this time of deposition is, within uncertainty, the same as the timing of a widely identified readvance, the Wester Ross Readvance, observed elsewhere in northwest Scotland. This extends the area over which this readvance has potentially occurred, reinforcing the view that it was climatically forced. | ||||||||||||||||
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