Underwater Archaeology

Date 14 August 2018 - 21 August 2018

Event ID 1087330

Category Recording

Type Underwater Archaeology

Permalink http://canmore.org.uk/event/1087330

NN 67393 36248 This work formed part of the Living on

Water investigation of Early Iron Age crannog-dwellers in

Loch Tay. The project is excavating a range of crannogs with

known EIA phases to collect structural timber samples for

dendrochronology and wiggle-match radiocarbon dating.

Dall Bay North crannog has seen previous work sample

five timbers for radiocarbon dating with two returning

Early Iron Age dates, both from alder timbers at the base

of the crannog mound. Two trenches were opened, 14–21

August 2018, at the base of the crannog mound where it

meets the natural loch bed. Trench 1 was located on the SE

portion of the crannog and Trench 2 on SW portion of the

crannog. Areas to the N side of the crannog were found to

have much greater accumulations of fine sediment, which

made exposing timbers for sampling more difficult. The

trenches were hand excavated and recorded using a range of

techniques, including photogrammetrically.

Trench 1 was 2 x 2m, and contained 17 in situ timbers.

The timbers were not exposed above the level of the natural

loch sediment, which was composed of fine silty sands, or

the rubble capping of the crannog. The timbers were mostly

horizontal alder elements, but four piles were also recorded,

the largest of which was only 0.12m in diameter. Contexts

composed of charcoal and ash spreads were interspersed

with contexts composed of bracken and brush wood. These

organic spreads interleaved with inorganic deposits of silty

sand, interpreted as natural sediment accumulation.

Trench 2 was 3 x 2m and revealed a similar stratigraphic

sequence with mostly horizontal alder timber elements

amongst contexts of charcoal, ash, bracken and brush wood

spreads. A total of 24 timber elements were recorded, 16 of

which were sampled. A perforated stone c200mm in diameter

was recovered from the trench.

Timber sampling was carried out by sawing the top off

vertical timbers, and slices requiring two cuts were used on

horizontal timbers where necessary. These samples will be

subject to dendrochronological analysis and wiggle-match

radiocarbon dating over the course of the project.

Archive: ADS and NRHE (intended)

Funder: Historic Environment Scotland

Michael J Stratigos – Scottish Universities Environmental

Research Centre (SUERC)

(Source DES Volume 19)