Underwater Archaeology Research Centre
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Underwater excavations

In 2003 the Underwater Archaeology Research Centre undertook excavations at Loch Arthur Crannog as part of the South West Scotland Crannog Survey.

The site was found to have been subject to multi-period occupation. Radiocarbon dates suggest that the main packwerk mound at Loch Arthur was constructed in one event at some point during the 4th to 3rd centuries BC. After a period of abandonment, represented by the deposition of natural loch silts, a boulder capping was placed on the original packwerk mound sometime in or after the 15th century AD.

General view of Loch Arthur Crannog.
Crannog positioned on Loch Arthur, South West Scotland. 

 

 Project overview

The crannog in Loch Arthur appears above water as a tree covered island, some 30 metres in diameter, which is connected to the shore by a muddy reed bed.  

In 1966-7, small-scale terrestrial excavations on the island revealed the footings of drystone/clay packed walls that were interpreted as the stone undercroft of a wooden framed building. The excavator dated the site to the 15th/16th century AD. However, in 1989, a vertical birch pile from the site was sampled for radiocarbon dating and provided evidence of Iron Age activity at the site.

Our 2003 small-scale underwater excavations shed further light to the chronology of the site, while our investigations revealed that the majority of the structure of this crannog lies underwater as the island visible from the shore appeared to sit on a much larger fully submerged structure.

 
Project outcomes

The site was found to have been subject to multi-period occupation.

Radiocarbon dates obtained during the excavations suggest that the main packwerk mound at Loch Arthur was constructed in one event at some point during the 4th to 3rd centuries BC. After a period of abandonment, represented by the deposition of natural loch silts, a boulder capping was placed on the original packwerk mound sometime in, or after, the 15th century AD.

Our investigations also revealed that the majority of the structure of this crannog lies underwater as the island visible from the shore appeared to sit on a much larger fully submerged structure. These two features could be distinguished by their composition, the upper mound (the island) being built primarily of large boulders within a well-developed soil, and the lower submerged structure of timber (alder and oak), organic deposits and stones. 

Over 50 alder timbers were exposed and recorded in Trench 1. These timbers were found within a matrix of organic deposits that also contained hazel nuts and woodchips as well as many fire cracked stones that were most likely used in cooking and dumped onto the site from occupation above. Trench 2 revealed a very similar structure in existence on the top of the submerged mound.

The deposits revealed in both trenches suggest that only foundational constructional material is present under water. The considerable lack of occupational debris seems to indicate that if any such deposits existed on top of the submerged mound, they have since been eroded away leaving only foundation deposits.

Finally, a small trench was also excavated on the dry area of the crannog to determine the relationship between the upper dry island and the submerged mound. The structure of the island was entirely artificial. Beneath a 0.8m thick layer of rounded boulders, horizontal alder timbers were encountered which had been laid in horizontal lines resembling the foundations of a floor. These two contexts were separated from each other by a thin layer of re-deposited loch silts indicating a period of inundation and abandonment between the two constructional phases. Significantly a sherd of medieval green glazed pottery was recovered providing evidence for medieval activity on the site.

 
Publications

HENDERSON, J.C., CRONE, B.A., AND CAVERS, M.G., 2003. A condition survey of selected crannogs in south west Scotland. Transactions of the Dumfriesshire and Galloway Natural History and Antiquarian Society, 77, 79-102.

HENDERSON, J.C., CAVERS, M. G., AND CRONE, B. A., 2006. The South West Crannog Survey: Recent work on the lake dwellings of Dumfries and Galloway. Transactions of the Dumfriesshire and Galloway Natural History and Antiquarian Society, 80, pp. 29-52.

Henderson, J.C., 2007. Recognising complexity and realizing the potential of Scottish Crannogs. In: Barber, J., Clarke, C., Crone, A., Hale, A., Henderson, J., Housley, R., Sands, R., Sheridan, A., eds. Archaeology From The Wetlands: Recent Perspectives. Edinburgh: Society of Antiquaries of Scotland. pp. 231-241.

 

 

Project team

Dr Jon Henderson (University of Nottingham)

Graeme Cavers (AOC Archaeology Group)

 

 

Underwater Archaeology Research Centre

The University of Nottingham
School of Humanities
University of Nottingham
University Park
Nottingham, NG7 2RD


telephone: +44 (0) 115 951 4842
email:jon.henderson@nottingham.ac.uk