Local and regional constraints on relative sea‐level changes in southern Isle of Skye, Scotland, since the Last Glacial Maximum

Abstract

New relative sea-level (RSL) data constrain the timing and magnitude of RSL changes in the southern Isle of Skye following the Last Glacial Maximum (LGM). We identify a marine limit at ~23 m OD, indicating RSL ~20 m above present c. 15.1 ka. Isolation basin data, supported by terrestrial and marine limiting dates, record an RSL fall to 11.59 m above present by c. 14.2 ka. This RSL fall occurs across the time of global Meltwater Pulse 1A, supporting recent research on the sources of ice melting. Our new data also help to resolve some of the chronological issues within the existing Isle of Skye RSL record and provide details of the sub-Arctic marine environment associated with the transition into Devensian Lateglacial climate at c. 14.5 k cal a BP, and the timing of changes in response to the Loch Lomond Stadial climate. Glacio-isostatic adjustment (GIA) model predictions of RSL deviate from the RSL constraints and reflect uncertainties in local and global ice models used within the GIA models. An empirical RSL curve provides a target for future research.

Palaeoenvironmental reconstruction of Loch Duart (NW Scotland, UK) since the Last Glacial Maximum: implications from a multiproxy approach

“…The transition between L1 and L2 is characterized by the presence of Charophyte oogonia, representing green algae which live submerged in fresh and brackish water (Moore, 1986) and often found at the isolation contact of Scottish isolation basins (e.g. Shennan et al, 2000; Best et al, 2022). The presence of Charophyte oogonia thus suggests the transition represents the isolation contact.…”

“…It has long been recognized that the complex relative sea-level (RSL) histories across the British Isles are intimately linked to the history of the BIIS via glacial isostatic readjustment and glacio-eustatic sea-level change (Flemming, 1982;Shennan et al, 2006aShennan et al, , 2006bSmith et al, 2019). The sedimentary record in Scotland has proven instrumental in refining models of RSL change (Shennan et al, 2000(Shennan et al, , 2006aBradley et al, 2011;Kuchar et al, 2012;Long et al, 2016;Best et al, 2022) which have been heavily influenced by records preserved in isolation basins, a common feature of the NW Scottish landscape. Specifically, isolation basins provide critical sea-level index points that anchor well-constrained sea-level curves for specific areas.…”

South Cuidrach

“…The finds embrace surface scatters of highly weathered and rounded artefacts that suggest an offshore origin, typologically identifiable Late Pleistocene and Early Holocene, unrolled lithic artefacts and an in-situ Late Mesolithic dwelling. Lying immediately above the dwelling is a raisedbeach deposit that is linked to the mid-Holocene sea-level increase (Best et al 2022).…”