Excavation

Date 16 July 2012 - 24 August 2012

Event ID 993173

Category Recording

Type Excavation

Permalink http://canmore.org.uk/event/993173

HY 303 129 Further investigation of the large Late Neolithic complex on the Ness of Brodgar was undertaken 16 July – 24 August 2012 in order to characterise more of the structures and activity on the site. Overall a more fluid, organic development of the site was revealed with potentially several of the other major structures remaining in use after Structure 10 was built.

The central hearth and surrounding occupation deposits of the secondary major remodelling of Structure 1 were exposed. Dumps of mixed charcoal-rich ashy clay were excavated from the S and W recesses exposing internal stone settings. A box-like structure, bound by a low upright slab to the N and a snapped orthostat on the E side, was exposed in the S recess. The top of a wall facing W was exposed in the W recess. Levelling deposits were removed from the northern bays either side of a central orthostat. This exposed additional stone settings, including a snapped orthostat, and a second central hearth. This hearth is surmounted by the main wall that forms the N side of the secondary major remodelling of the Structure 1 building. The large dividing orthostat was cut into the second hearth. The use of the internal area then focused upon the southern central hearth to the S. This was surrounded by a series of interleaving clay floor deposits and thin occupation spreads. The southern central hearth was used throughout the majority of the life of the building, until it was sealed by a semi-circular structure (excavated last season). The occupation and floor layers remain unexcavated.

The full extent of the intra-mural passage that runs along the E side of Structure 1 was exposed. The passage is c8m long and originated as a passage between Structure 19 and Structure 1. Structure 11 may have been added to the S end, extending the passage around to the southern entrance of Structure 1; however, the relationship between Structures 11 and 19 is as yet unclear. The passage still partly functioned with the later construction of Structure 7 above Structure 19. The internal passage flagstone surface continued to the N where it rises up and respects a secondary phase wall of Structure 1. The S end of the passage contained numerous examples of decorated stones.

Excavation continued in the internal area of Structure 7 around the central hearth. The final patches of clay floor and ashy midden spreads were removed exposing a substantial levelling layer. This abutted the central hearth stones, which were found to overlie an earlier hearth, perhaps from Structure 19. The levelling layer also continued below the outer wall of Structure 7 confirming the late position of this building in the sequence. The levelling layer was excavated in quadrants around the central hearth exposing a lower ashy surface/levelling. The N and E walls of Structure 19 remained elusive and appear to have been extensively robbed.

A rectangular flue feature to the S of Structure 7 was fully excavated. This had upright stones demarcating a central area full of burnt stone with a smaller rake-out area to the S full of charcoal-rich layers. The burnt stones did not appear to have been burnt in situ and were likely to have been deposited in this condition. The structure may have been used as an oven.

Structure 21 was discovered to the W of Structure 1. A short length of curvilinear stone built wall was exposed that represents the corner of a substantial building, perhaps similar in size to Structure 1, but that had been substantially robbed of stone. The foundation stones of the wall were found to overlay a layer of clay that abutted the foundation stones of the neighbouring Structure 1 wall. Therefore, Structure 21 was slightly later (similar to Structure 14), but broadly contemporary. The building continues outwith the excavation trench. Later activity over the remains of Structure 21 was represented by an area of paving and insubstantial wall lines.

The main trench was extended to reveal the full extent of Structure 14 that was first revealed on 2011. Although its northern side was badly robbed a full plan was revealed, c10.6 x 9.2m overall. The interior of the building was sub-rectangular and roughly symmetrical along its W–E long axis. Each side of the structure had a small corner niche to the W, and two large recesses defined by piers and a corner buttress. The W wall had two small piers defining a shallow recess where a secondary dresser possibly stood, while the corner buttresses to the E defined an opposed end recess. The interior arrangement of corner niches and side recesses is directly paralleled in Structures 8 and 12, and the bowed sides are also paralleled with the former. Entrances were revealed in both the middle of the S side and in the E end of the structure. The latter entrance had been blocked. The occupation deposits and various orthostatic fittings, including two hearths, within Structure 14 were revealed in plan but not excavated. Three special deposits had been left on the surface of the latest occupation horizons comprising a polished igneous stone tool placed on an incised slab, an exceptionally fine polished gneiss axehead and a complete Grooved Ware vessel. Several related drains were revealed outwith Structure 14 as paved areas and a later small building, Structure 22.

The upper mass fill layers within Structure 12 were further investigated, with the majority of these layers fully removed, and the four stone robbing cuts along the inner face of the E wall were fully excavated. The WNW outer walls of the annexe were further investigated, with a short length of later wall abutting the annexe completely removed.

Upon the removal of the last major midden infill deposit a number of more discreet midden dumps, along with a shallow pit, some possible structural features and potential floor layers were uncovered. The top of a number of possible associated stone furniture features were revealed during this season, however none of these were fully uncovered, and their full extent and nature remains to be seen. These include wall lines, orthostats and a stone box.

The blocked up, original entranceway located in the WNW corner of Structure 12, was revealed to a height of 0.7m. A door jamb associated with this entranceway, and incorporated into the NNE side of the adjacent pier was also uncovered. In the S end wall a shallow but full height recess was uncovered directly in line with the narrow entrance in the N wall.

Very limited excavation was carried out in Structure 8 this season, as it was deemed necessary to bring the SSW half of the structure into phase, before the previously exposed floor deposits can be excavated. However, one of the hearths was half sectioned and the floor deposits were sampled using a portable XRF machine at 0.5m intervals.

In the SSW end of Structure 8 the depositional sequence was characterised as thick midden, or midden enhanced soil backfill deposits, which overlay layers of demolition rubble, interspersed with further deposits of midden. At the end of the season, a probable secondary occupation horizon was revealed, which appears to overlie further deposits of demolition rubble. Further structural features were exposed, which form the SSW continuation of the WNW wall of Structure 8, along with two piers and orthostatic divisions within the interior of this structure. The structural remains in this area were heavily truncated by later activity, associated with Structures 10 and 7, and the flue-like structure (see above).

The stratigraphic sequence in this key area of the site was also clarified. Deposits were interrelated across the area, to examine the phasing between the various structures. Cut features relating to the robbing of the masonry of the outer wall, and deposits which overlie the outer passageway of Structure 10 were excavated to refine the stratigraphic sequence. These included the excavation of the animal bone-rich layer, encountered elsewhere within the upper fill of the outer passage of Structure 10.

Limited excavation was undertaken in the Central Midden Area, between Structures 1, 8 and 12. In this area, large concentrations of Grooved Ware pottery were present within the midden deposits. Significantly, a deposit of trample was identified which overlay a clay surface. These layers lead from the outer annexe of Structure 12, to an orthostatic setting, proving the contemporaneity of these structures.

Work within Structure 10 concentrated on further exploring its interior and sequence. Features and deposits relating to the secondary cruciform shaped central chamber were investigated, including slots for several robbed out orthostatic arrangements. The N and W dressers, and the NW pier were dismantled. A polished stone unperforated macehead/pestle was discovered in the eastern recess to the S of the entrance passage, with a polished stone axehead revealed under the western dresser. The floor of this secondary use sat on a thick, very mixed rubble and clay deposit that is presumed to seal the primary deposits that relate to its original square plan with rounded corners. Confirmation of the primary plan was revealed by the robber trench in the NE corner. This perfectly preserved trench had removed all the upper stonework but had left in place the original massive stepped foundation slabs.

Samples for archaeomagnetic dating were taken from hearths in Structures 1, 7 and 8. If proved usable more hearths will be sampled in 2013.

To accompany the large catalogue of Neolithic art already discovered several other examples were revealed this season. A large assemblage of typical Late Neolithic cultural material was also uncovered including several more polished stone artefacts, two more blades of pitchstone, and large quantities of Grooved Ware some exhibiting the use of different coloured clays, slips and applied coloured pigments.

Report: Orkney SMR and RCAHMS

Funder: Orkney Islands Council, Orkney College, Robert Kiln Trust, Royal Archaeological Institute, Orkney Archaeology Society and British Academy

Nick Card, ORCA

, Orkney College UHI

2012