To a continental/ mainland mindset, islands can often seem marginal, although in fact they may have been at the centre of widely-connected seaborne trade routes. Despite the scope for maritime trade, material acquisition may be difficult. Island flora and fauna are usually impoverished relative to continents, particularly with respect to terrestrial species, and mineral resources may also be quite poor. In this scenario, items cast ashore by the sea (for simplicity I’m going to call them ‘flotsam’, although that term implies a specific provenance much narrower than the range of things I’m going to be talking about) can represent a valuable source of raw materials This post is going to briefly consider this in relation to the Outer Hebrides, Scotland, because those are the islands with which I’m (archaeologically) most familiar.
The Outer Hebrides (also known as the Western Isles) lie to the north-west of Scotland, separated from the mainland by a sea called the Minch, some 50 – 80 km wide. There’s a deep trough in the Minch, which means that there was unlikely to have been a land bridge to the mainland at any point during the Quaternary. To my eyes, raised in the gently hilly, verdant and closely managed landscape of southern England (see Colleen’s comments on this at Middle Savagery), the Western Isles are a wild, rugged place. It rains a lot, and is very windy. Although pollen and snail records indicate that there was fairly extensive tree cover in earlier prehistory, human activity and a change in climatic conditions with the onset of the Little Ice Age have left the islands virtually treeless. During the last glaciation most, if not all, of the island land surface was under ice some 400-700m thick, therefore the terrestrial plants and animals of the Outer Hebrides are all post-glacial arrivals. The geology of the islands is almost entirely Lewisian gneiss, which dates to the Precambrian, almost 3 billion years ago. It is not a good building material, as it is friable, does not produce regular blocks, and disintegrates when heated (Barber 2003, 21).
Despite these conditions, humans have lived on the islands for at least 9000 years. The earliest known site is at Northton, on the Isle of Harris, although no occupation dating to the Mesolithic has yet been found, most likely because sea level rise and the advance of blanket bog conditions across much of the interior since then make older sites difficult to find. In these resource-poor circumstances, the sea becomes incredibly important. There is open sea between the west coast of the Outer Hebrides and North America, and driftwood is frequently cast on the shores. Driftwood timber is a source of building material as at Iron Age Dun Vulan on South Uist and Dun Bharabhat on Lewis, as well as fuel for fires. At Norse-period Mound 3 of Bornais on South Uist, larch or spruce charcoal was identified. Neither taxon is native to Britain – the wood must have originated in North America or northern mainland Europe (Gale 2005, 163). Finds of probably North American spruce charcoal have also been reported from Barra and from Barvas on Lewis (Dickson 1992, 50). As late as the nineteenth century, household dressers were generally made from driftwood (Webster 1999, 59). An especially interesting piece of driftwood – a carved statue – is on display at Kildonan museum on South Uist (see http://www.kildonanmuseum.co.uk/_wp_generated/wp2d9eacb1.png).
Stone may also be cast ashore. Pumice (which can float), most likely from the Katla volcanic system in southern Iceland, is a relatively frequent find at Hebridean sites (e.g. Newton & Dugmore 2003), and is occasionally fashioned into perforated floats for fishing nets, or used as sharpening stones. Similarly, flint tools found at archaeological sites in the Outer Hebrides may be from beach pebbles as there is no natural source on the islands. There is, however, a flint source at nearby Skye (Finlay 2003, 113).
Beached marine animals are another important resource. Whale strandings in particular are reasonably common. Whale bone is useful as a raw material for building and for tool and ornament production. In the Outer Hebrides, whalebone artefacts include combs, knifes, mattocks, pegs, plates, chopping boards and “pot lids” (Mulville 2002). The bone also has a high fat content, and is useful as fuel (blubber may also be used as fuel). At Iron Age Bornais, a number of burnt whale bones were found in association with metalworking debris (Mulville 2002, 44).
The utility of these gifts from the distance (as well as more local coastal resources such as fish, shellfish and seaweed) has implications for the organization of island societies. Routine exploitation of the coastline is an important task, and the unpredictable nature of, for example, driftwood landings, requires vigilant monitoring of the shore (Sharples 2005, 162). Access to these resources may be subject to close controls (indeed in the UK, items washed ashore are still subject to the control of the Receiver of Wreck). In the context of island and coastal archaeology, the distance implicit in the wide expanse of the oceans can be a positive influence, capable of bringing in materials otherwise unavailable (or only available via complex and potentially expensive trade arrangements) to past societies.
Barber, J., 2003. Bronze Age Farms and Iron Age Farm Mounds of the Outer Hebrides. Scottish Archaeology Internet Reports No 3. Edinburgh: Society of Antiquaries of Scotland. Online at http://www.sair.org.uk/sair3.
Dickson, J.H., 1992. North American driftwood, especiallyPicea (spruce), from archaeological sites in the Hebrides and Northern Isles of Scotland. In: J.P. Pals, J. Buurman and M. van der Veen (Editors), Festschrift for Professor van Zeist. Review of Palaeobotany and Palynology, 73, pp. 49-56.
Finlay, N., 2003, Lithic Assemblages, in Barber, J., 2003. Bronze Age Farms and Iron Age Farm Mounds of the Outer Hebrides. Scottish Archaeology Internet Reports No 3. Edinburgh: Society of Antiquaries of Scotland. Online at http://www.sair.org.uk/sair3, pp.133-134.
Gale, R., 2005. The Shore. 3. Wood, in N. Sharples (ed.), A Norse Farmstead in the Outer Hebrides: excavations at Mound 3, Bornais, South Uist. Oxford: Oxbow. p. 163.
Mulville, J., 2002. The role of cetacea in prehistoric and historic Atlantic Scotland. International Journal of Osteoarchaeology, 12(1), pp.34-48.
Newton A.J. and Dugmore A.J., 2003. Analysis of pumice from Baleshare, in Barber, J., 2003. Bronze Age Farms and Iron Age Farm Mounds of the Outer Hebrides. Scottish Archaeology Internet Reports No 3. Edinburgh: Society of Antiquaries of Scotland. Online at http://www.sair.org.uk/sair3 pp. 135-138.
Sharples, N., 2005, A Norse Farmstead in the Outer Hebrides: excavations at Mound 3, Bornais, South Uist. Oxford: Oxbow
Webster, J., 1999. Resisting Traditions: Ceramics, Identity, and Consumer Choice in the Outer Hebrides from 1800 to the Present. International Journal of Historical Archaeology, 3 (1), pp 53-72.