An exceptional axehead, Iron Age remodelling and a carved stone ball – seasons 2012-2013
Welcome to the fourth part in our series looking at how the Ness of Brodgar excavation has progressed – and ideas changed – over the years via dig director Nick Card’s annual brief summaries for Archaeology Scotland’s Discovery and Excavation in Scotland.
Today the spotlight falls on the 2012 and 2013 seasons.
Annotations in red put the archive information into current site context.
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.
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 [pictured right] 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.
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.
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.
- Intrusive archaeological evaluation and watching brief in advance of a raised and cut/fill footpath along part of the SW shore of the Loch of Harray between March and July 2012. The development is adjacent to Brodgar Farm and the Neolithic complex at the Ness of Brodgar. The results of the test pitting and watching brief showed that there were four distinct concentrations of archaeological features within the site boundary.The features uncovered within Areas 2 and 4 indicate a probable continuation of the Neolithic activity uncovered at the Ness of Brodgar directly to the southeast. However, since the groundworks would not impact upon these features, they were recorded, sealed, and left in situ. The remaining archaeological features uncovered during the watching brief were either undated or relate to the post-medieval use of the area.
Further investigation of the large Late Neolithic complex on the Ness of Brodgar was undertaken, 15 July – 23 August 2013, in order to characterise more of the structures and activity on the site. Relationships between some of the structures were clarified and a stringent sampling procedure was implemented for tackling the floor deposits. Micromorphic samples were also taken through floor and midden deposits.
In Structure 1, internal floor deposits consisted of extensive occupation layers and discrete patches of occupation and clay floor material around the central hearth and abutting the piers.
Small box sections excavated for soil micromorphology sampling revealed a complex floor stratigraphy, c0.13–0.23m thick, consisting of numerous thin occupation and clay floor layers. Externally, excavations on the W side revealed that Structure 1 was built on a sequence of midden and levelling layers (0.52m thick) which seal glacial till.
A section through the paving in the intramural passage on the E side of Structure 1 demonstrated that Structure 19 was constructed later than Structure 1. The passage is underlain by a stone-lined drain.
To the S of Structure 1, extensive dumps of ashy midden had been heaped around a large orthostat which is aligned on the S entrance. The midden heap also sealed rubble and irregular structural remains which have yet to be excavated. This rubble continued below Structure 11 and this building was constructed at this level.
Last season it was established that Structure 21 was constructed just after Structure 1 and more of this building was exposed in 2013. This included the remains of an inner wall face.
The majority of Structure 7 was removed to investigate the underlying remains of Structure 19.
Following the excavation of the remaining quadrants of levelling material around the Structure 7 hearth, the hearth itself was removed, revealing an earlier hearth directly below.
A possible oven, containing burnt stone, with a flue, was found to the N of the later central hearth. Along with the oven to the S excavated in 2012, the northern oven and sequence of hearths indicates varied and perhaps intensive use of this area (large-scale cooking).
Structure 19, and later Structure 7 above, was of piecemeal construction and modification as this area developed, and probably never roofed.
Excavation within the previously exposed NNE portion of Structure 8 was limited to half sectioning the SSW portion of the central hearth, in order to expose burnt deposits suitable for archaeomagnetic dating. The floor deposits in this area of the structure were left in situ until the rest of the structure has been fully exposed.
In the SSW portion of Structure 8, deposits associated with the initial dismantling and decommissioning of the structure were removed. These deposits consisted of interleaved deposits of demolition rubble, including further evidence of dressed roofing stones and deposits of midden material, and sealed floor deposits associated with the use of Structure 8.
A further rectangular hearth was partially exposed, which was offset from the central axis of the building, towards Recess 7.
In the central area of the SSW portion of Structure 8, a large mound of secondary in situ burnt deposits was revealed, which measured 3m NNE–SSW by 2.2m WNW–ESE. This mound of burnt material is unusual, as it does not appear to be associated with a formalised hearth setting at this level. The sequence of deposits infilling Structure 8 were block sampled for soil micromorphology.
Deposits overlying the outer passageway of Structure 10 were excavated, in order to clarify the stratigraphic relationships between deposits that were infilling Structure 8 and the outer passageway of Structure 10.
In the Central Midden Area between Structures 8 and 12, excavation was limited to clarifying the relationships between a deposit of trample, midden deposits, two clay surfaces and the annexe of Structure 12.
Work in Structure 10 further explored its interior and sequence.
Features and deposits relating to the secondary cruciform shaped central chamber were investigated, and removed including several orthostatic arrangements. The two surviving SW and NE later corner buttresses were partially removed.
Under the NE one a six-knobbed carved stone ball was discovered, while under the SW one a large and elaborately decorated stone block was revealed. Both seem to have formed part of a foundation deposit associated with the secondary reconstruction and remodelling of the interior of Structure 10. [A similar pattern was noted under the other corner buttresses, with deposits including a human arm bone, large cattle leg bones, decorated stone and a the bone from a sea eagle wing].
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. More of the robber trench infill was removed, particularly around the SE corner, to confirm the original square plan of the interior.
With the removal last year of the upper mass fill layers in Structure 12 deposits were reached that signified a later phase of reuse of the building.
A large hearth was revealed in the S half of the building in association with a large spread of cattle bone. A large number of stone roofing slates were also recovered from the interior. In its primary phase Structure 12 had an entrance in its NW corner, and internal buttresses at both ends.
This entrance was then blocked and a new narrow entrance was ‘punched’ through its N end when the annexe/porch arrangement was added. The annexe utilised walling from at least two earlier structures that underlie Structure 12.
Work on Structure 14 was confined to its interior floor deposits which were gridded and sampled. The complexity of the floors necessitated two narrow sondage trenches being excavated across them in order illuminate their stratigraphy. These revealed a sequence of numerous floors and potential phases.
Trench T was opened for the first time in 2013.
The trench was placed to investigate a c45m diameter mound (HY31SW 20) that rests upon the eastern tip of the spit of land upon which the Ness of Brodgar sits.
The mound is clearly defined on its E and S sides, blends into the natural slope on its W side and is partly truncated by the road on its N side. The trench, which was placed to intersect two concentric curvilinear features and a possible enclosure identified through geophysics, measured 7 x 15m and was aligned with its long axis cN–S. The curvilinear features were thought to be revetment walls, which raised the possibility that the mound was a chambered tomb. Accordingly, the principal objective of the excavation was to define the date and type of the mound.
The excavation revealed that the mound (at least in the upper levels so far encountered) was constructed from vast amounts of midden material.
A significant later remodelling of the mound was represented by the construction of a revetment wall built to contain a large quantity of rubble and stony soil that seems to form a collared platform around the mound.
The midden mound is likely to be Neolithic in date; the date of the remodelling of the mound is uncertain but presumed to be Late Neolithic [we now know the remodelling dates from the Iron Age]. Evidence for robbing of the stony platform was provided by a large quarry pit that produced some fragments of iron.
More samples for archaeomagnetic dating were taken from hearths in Structures 8, 12, 14 and 16 by Dr Cathy Batt and Dr Zoe Outram of Bradford University with support from the British Academy.
To accompany the large catalogue of Neolithic art already discovered many other examples were revealed and catalogued this season, taking the total number discovered to date to 670 [in 2020 this figure is well over 1,000].