Excavation

Date 17 June 2009 - 12 July 2009

Event ID 608662

Category Recording

Type Excavation

Permalink http://canmore.org.uk/event/608662

ND 4542 8688 Excavation work continued 17 June–12 July 2009 as part of on-going research on the Orcadian Iron Age. The principal aims were to understand and further reveal a massive Atlantic roundhouse or broch-like building (Structure A) that makes up a large part of the mound and to continue to investigate the later Iron Age settlement (Structural areas B, C, D and E) that surmounts and intrudes into the building fabric of Structure A. The main focus of work was an open area trench of c20 x 20m.

The S and SW parts of Structure A, a massive roundhouse of over 22m in diameter, were further defined in an extensive band of work across the southern half of the building. In the SE the main entrance of the building was excavated.

During 2008, the upper deposits in the entrance had been found to consist of modern infill, and an episode of

antiquarian excavation was suspected. A complete excavation of this material confirmed this assessment. The excavation of the entrance area revealed a finely built passage surviving to a height of c1.5m and 1.3m wide. Slabs projecting from the wall faces form substantial door jambs, and a poorly preserved void on one face may indicate the presence of a bar-hole. The base of the passage was surfaced with a flag floor. The entrance is relatively simple in its construction with no side-cell or ‘guard chamber’ obvious as yet. A wall was uncovered at the inner end of the entrance passage that effectively blocked off the opening into Structure A. The stratigraphy indicates this wall was constructed at the same time that the interior of Structure A was deliberately infilled with rubble. At the southern (outer) end of the entrance passage another wall had also been constructed against the outer wall face of Structure A to block the entrance passage.

Whilst revealing extensive areas of the Structure A wall head, a well-built intramural gallery was revealed on the SW sector of the building. This T-shaped gallery ran S and N of a short entrance passage opening off the inner wall-face of Structure A. The northern part of the gallery contained the remains of a staircase. Only three stairs remained, the rest having been removed when large sections of the upper superstructure of the roundhouse were reduced at the end of its life. Nevertheless, the remnant staircase indicates that Structure A must originally have been a building of some height. Given that the staircase begins at a height of c1.5m above the inner floor of the roundhouse, it indicates that the staircase originally rose to an upper floor in Structure A. Structure A would have been an architecturally complex building, but despite this, its rubble and clay wall-core, as revealed in 2007, shows that it does not possess all of the traits of a conventional ‘broch tower’.

The second major area investigated this season was the later Iron Age settlement, which covers large parts of the remains of the Atlantic roundhouse and which was clearly reduced in height in preparation for the establishment of the post-roundhouse settlement. The character of this later settlement is such that it extends around the circumference of the Structure A superstructure. In many places individual buildings intrude into the physical fabric of Structure A in the manner of bites taken out of an apple. While this appears to be very unusual in Orcadian terms, a similar arrangement of later Iron Age settlement in relation to brochs and other

substantial roundhouses is attested to in Caithness. At least three major structural groups radiate around the Atlantic roundhouse ruins. On the N and NW there is a substantial complex of buildings and features grouped as Structure B area, which lie across the rubble infill and over the wall head of Structure A, while in the NE Structure C is a large building that intrudes into the wall of the Atlantic roundhouse.

Structure E in the SW is again embedded in the remains of A. Excavation of the intramural staircase within Structure A, The Cairns Excavation of the Structure B area was extended N and W to allow further investigation of this complicated suite of remains. A myriad of new walls and cellular features were identified, as well as hearths, wall-piers and orthostatic partitions. Essentially, a large rectangular building or two such buildings seem to have been succeeded by a less regular series of structures with curvilinear architecture and further

cellular arrangements. Of note was the presence of a large pit that had been dug into the northern floor space of Structure B late in its life. The pit contained decorated spindlewhorls, antler mounts and an extensive assemblage of animal bone, including many cattle mandibles and red deer antler. The pit was sealed with a large rotary quern. Most remarkable of all, the pit contained a small anthropomorphic head with clearly carved eyes, nose and mouth.

Work continued in Structure C, a large sub-circular building, which was further defined in outline and shown to be complex and substantial. Of particular interest was the excavation of a sub-circular furnace or kiln feature with a flue arrangement, an associated clay floor and heat-affected deposits spread across the building. Finds included a clay mould possibly for a ring-headed pin, a tuyère fragment, copper alloy pins, crucible fragments and various ferrous objects of indeterminate nature.

Structure E was fully excavated. This large rectangular building, with a rounded gable end on the N, appears to

have been open on the southern end. No discernible floor material was observed and the building was partly taken apart to allow investigation of the section of Structure A that it was built into. This work led to the discovery of another building directly beneath it, which was laid out on the same alignment. The floor deposits of this building appear to be well preserved and excavation indicated a part earthen, part slabbed floor. A substantial central rectangular hearth was also uncovered. Exploration of this building will commence next season.

From the work on the later settlement, it can now be stated that there are probably at least six later buildings nestled into the bulk of the ruins of Structure A. These remains almost certainly constitute the uppermost suite of buildings to have been laid out on the mound at The Cairns. It is probable that an even more extensive set of earlier buildings lies beneath the later Iron Age settlement. Previous work established that archaeological remains extend at least 20m beyond the outer wall face of the Structure A Atlantic Roundhouse.

A geophysical survey was undertaken by OCGU beyond the main excavation trench to establish the extent of the archaeological remains and to ascertain whether an enclosure ditch might surround the Iron Age settlement.

Archive: Orkney SMR and Orkney Museums Service (intended)

Funder: Orkney Islands Council, Scapa Flow Landscape Partnership, and Cardiff University Archaeology Department

Martin Carruthers – Orkney College