Abstract
Understanding the extent, retreat dynamics and climate-glacier coupling of the Scottish Ice Sheet during the Last Glacial-Interglacial Transition (LGIT) is hampered by a highly fragmentary geomorphological record, and is dependent on a precise and accurate dating framework to constrain deglaciation. On land, readvance of the retreating ice margin is recorded in part of NW Scotland by moraines of the Wester Ross Readvance at ~15.4-15.8 ka, preceding the Lateglacial Interstade and the Loch Lomond Stade ~12.9-11.7 ka. While the number of dated landforms has increased in recent years, the LGIT chronology in NW Scotland is primarily based on a limited number of samples per site, using Terrestrial Cosmogenic Nuclide Dating (TCND) methods that can yield conflicting or uncertain results. This highlights the value of developing complementary dating methods.
Previous studies have questioned the reliability of the Schmidt hammer exposure dating (SHD) technique on lithologies other than granite. This research (i) evaluates the use of SHD on sandstone in the NW Scottish Highlands; (ii) develops a local, lithology-specific calibration curve; (iii) applies this to estimate the age of undated surfaces and tests existing interpretations of landscape change during the LGIT. Field results from a 1,500 km2 area of NW Scotland conclude that SHD can detect significant differences (p <0.001) between Torridonian sandstone surfaces of Wester Ross Readvance and Loch Lomond Stadial age. Based on 31 existing, re-calibrated 10Beages, a calibration curve was generated (R2 = 0.58, p <0.001) for the period ~18-11 ka BP, and applied to 17 undated Torridonian sandstone surfaces. Our findings support the view that on selected lithologies and with rigorous adherence to careful field procedures, SHD can represent a valuable, cost-effective and reliable tool for obtaining large numerical dating samples for landforms in formerly glaciated terrain.
| Original language | English |
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| Number of pages | 1 |
| Publication status | Published - 7 Jan 2024 |
| Event | Quaternary Research Association Annual Discussion Meeting 2024: Changing Resolutions in Quaternary Science - Hybrid event, Manchester Metropolitan University and The University of Manchester, Manchester, United Kingdom Duration: 4 Jan 2024 → 7 Jan 2024 Conference number: 60 https://sites.google.com/view/qra2024/home |
Conference
| Conference | Quaternary Research Association Annual Discussion Meeting 2024 |
|---|---|
| Abbreviated title | QRA 2024 |
| Country/Territory | United Kingdom |
| City | Manchester |
| Period | 4/01/24 → 7/01/24 |
| Other | The meeting theme has been chosen to encourage contributions from all areas of Quaternary research. We welcome contributions relating to multiple concepts of 'changing resolutions'; from advances in measurement precision, data resolution, and timescales through to a consideration of the changing practice of Quaternary research. For example, this could include changing resolution(s) in: - Dating techniques and their application - Stratigraphic records, including annually laminated records of all types (lake and marine sediments, ice cores, tree rings, speleothems, shells etc.) - Imagery on all scales, from Digital Elevation Models to electron microscopy - Detection and analysis of all types of materials, from DNA to biomarkers to elemental analyses - Understanding of barriers to inclusion in Quaternary research. |
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