A high-resolution seismic stratigraphy from a Scottish sea loch and its implications for Loch Lomond stadial deglaciation

• Main Authors: Dix, J.K., Duck, R.W.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2000
• Subjects: Loch Lomond; Tidewater
• Online Access: https://eprints.soton.ac.uk/58372/; http://www3.interscience.wiley.com/journal/73001070/abstract

A detailed high-resolution seismic stratigraphy, calibrated by core data and terrestrial geomorphological mapping, has been constructed for Loch Ainort, Isle of Skye. This study has provided a palaeoenvironmental history of the area as well as important corroborative evidence for the stepped deglaciation of the Loch Lomond Stadial ice-field on Skye. The Ainort Glacier reworked pre-Loch Lomond glacial deposits terminating in a grounded tidewater ice-front potentially 800 m beyond the previously extrapolated limit. The first stage of deglaciation was characterised by the formation of De Geer moraines indicative of a period of interrupted retreat. The second phase, by contrast, produced hummocky relief with sporadic linear moraines suggesting periods of uninterrupted retreat with occasional stillstands/readvances. Paraglacial reworking of terrestrial slopes resulted in the deposition of thick, subaqueous, debris flows which graded into fluvioglacial dominated sediments and ultimately modern fjordic deposits. The identification of an initial period of active retreat punctuated by numerous readvances correlates directly with the terrestrial record. However, the offshore stratigraphy suggests that although the second phase was dominated by uninterrupted retreat, occasional stillstands/ readvances did occur.