Identification of the Icelandic Landnám tephra (AD 871 ± 2) in Scottish fjordic sediment

Certain marginal marine environments, such as the Scottish fjord systems, contain high-resolution records of palaeoclimatic change in which decadal to centennial climatic events can be resolved. This paper explores the possibilities of using tephrochronology to stratigraphically constrain the timing of such events in the Loch Sunart record (MD04-2831) on the NW coast of Scotland (UK). One tephra horizon (containing both silicic and basaltic shards) is identified within Late Holocene sediment with geochemical analyses of the basaltic shards suggesting an origin in the Veidivötn-Bárðarbunga volcanic system. Radiocarbon age estimates and stratigraphic information suggests that the AD 871 Landnám tephra is the most likely candidate. The shards identified within this horizon appear hydrated and indicate the operation of post-depositional weathering processes possibly influenced by the saline conditions of the fjord environment.