Monument record 1731 - DUNASBROC, LEWIS

NB46SE 19 4713 6215.

(NB 4716 6215) Dunasbroc (NAT)
OS 6"map, (1965)

Dunasbroc, pointed out at NB 4713 6200, and wrongly positioned on OS 6" 1965, is a conical stack, on which a fragment of low walling can be seen, apparently constructed of quite small, poor quality stones, unlike the wall footings of a dun.
Visited by OS (NKB) 16 June 1969.

NB 4713 6215 Dunasbroc (NB46SE 19) is a small conical stack. Although there are no structural remains on the flat summit of the stack, a series of eroding sections below the summit on the eastern landward face reveal ephemeral structures and occupation debris.
A small section of drystone walling measuring approximately 4m long and 0.5m high (at least four courses) is present below the summit, and further traces of walling were recorded below and to the S of this. A large decorated fragment of possible Neolithic or Bronze Age pottery was recovered from an eroding face to the N of the main section walling. Another eroding face, directly above the walling, revealed further occupation debris, including a smoothing stone and charcoal deposits. An apparent access ramp or path appears to have been terraced into the eastern face of the stack, running from the deposits described above to its base. Occasional eroding sections of soil are present along this, revealing charcoal lumps, animal bone and further pottery sherds.
Barrowman 2004, 133

General Description
There were no obvious structures on the stack, and at first it seemed that the archaeological evidence would be restricted to deposits from a series of eroding sections. These sections were scattered through many little ramps and terraces on the steepest, landward face. At first the underlying shape was given no more than a cursory glance, but after discovering rich occupational layers and artefacts near the summit, the terraces were re-examined and found many cases to be supported by little walls and revetments, running along the contour of the stack, and make use of natural outcrops towards the base of the slope.
Section A
A small 0.3m by 1m, east facing eroding section yielded pot sherds, unworked quartz chips and pebbles, small flecks of charcoal and two rough 300mm long slabs of gneiss.The sediment consisted of a very compact, almost concreted, silty sand, varying from light grey and shell-rich at the top to darker brown organic rich lower down, without any distinct context change and with charcoal flakes throughout. Potsherds were also found throughout. The exposed nature of these occupational deposits demonstrates the lack of vegetation cover on this part of the site. Approximately 100mm below the top section, within the lighter coloured sediments and towards the south end, two large decorated body sherds of carinated pottery and one rim sherd were discovered, lying laterally and very close to each other, as if smashed in situ.
Section B
The large loose section on the east face measures c. 6m in length by c. 2m high. It consists mostly of a mixture of bedrock and tumbled dressed gneiss slabs c. 300 by 500mm. There are two distinctive soil layers, the uppermost being identical to that of section A. The lower consists of a grey-brown compacted silt with occational pottery sherds, charcoa lumps and broken shells throughout, and is damaged significantly by rabbit burrows. It also contained lumps of quartz measuring c. 20 - 30mm and a stone smoothing tool.
Section C
This eroding section measures approximately 1.5m by 1.5m. Again, bedrock outcrops toward the base or this scar and many blocks and slabs of gneiss stone tumble are seen throughout. Two large slabs to the south end could possibly be structural and related to section D. The uppermost soils here are very similar to those in section A and the top of section B, although lacking pottery, and a new context of fine, light brown silty loam wit no finds or inclusions is visible towards the bottom 0.5m of the section.
Section D
This is the most distinct structural element encountered on Dunasbroc. At least four courses, representing c. 0.5m, of dressed gneiss drystone wall runs parallel with the contour of the stack for 4m, on the landward face. The block size is in general more substnatial than others on the stack, bein gc. 400mm by 200mm on average. To the south the wall disappears under vegetation, and to the north has probably fallen away.
Section E
This section contains four courses of dressed gneiss drystone wall covering an area c. 1m long by 0.5m deep, and resting upon bedrock. It may have originally continued to the north but has since collapsed. This section is only 1m downslope of section E, and could be related to the wall there, although it is clear that the blocks are less substantial here, being 200mm by 100 mm in size. The courses are very well fitting.
Area F
This is a c. 3m wide ramp which forms the access route to the site. It is likely to be an outcome of the slumping and erosion of whatever buildings were originally present.
Section G
A little drystone wall, three courses high, covering an area c. 1.2m by 0.5m, of dressed gneiss slabs measuring c. 400mm x 150mm.
Area H
this is the flat area on the top of the stack. C. 15m by 6m, formed by bedrock and soil deposits, conceivably anthropogenic.
Section I
Another small piece of drystone walling, at least three visible courses of dressed gneiss slabs c. 400m by 150mm. Not very well constructed, built into a cranny between bedrock outcrops.
Barrowman & McHardy, 2005, 28-39

In 2005, limited trial excavation was carried out on Dunasbroc. Two trenches were excavated, one 10 x 1.5m (trench 1), and a second 2 x 1m (trench 2).
Trench 1 revealed a complex of walls, cuts and related burnt deposits. Trench 2 revealed a rough revetment, with related deposits. Finds included flint, quartz, over 400 sherds of pottery, and burnt bone. Initial dates, from the finds, suggest initial use in the Neolithic, and reuse in the Iron Age.
McHardy 2006, 13-18

Council for Scottish Archaeology, 2004, Discovery and Excavation in Scotland (Bibliographic reference). SWE41193.

Chris Barrowman & Ian McHardy, 2005, STAC Severe Terrain Archaeological Campaign, Isle of Lewis 2004 (Unpublished document). SWE41102.

Ian McHardy, 2006, The STAC project, 2005: Data structure report (Unpublished document). SWE41145.