By Dan Lee
Projects officer – ORCA
A team from ORCA (Orkney Research Centre for Archaeology), based at Orkney College, were joined by students from Durham University and local volunteers, who received training as part of the Scapa Flow Landscape Partnership scheme.
Last year’s excavation established that Outer Green Hill, a large grassy mound on the north coast of Cantick, was not the remains of an Iron Age broch as long assumed, but a substantial Neolithic chambered cairn.
The tomb forms the heart of the prehistoric landscape of Cantick and the Bronze Age monuments, consisting of burial mounds, mounds, possible structures and a burnt mound, were constructed at a respectful distance to the east and south. Investigations this year focused on the funerary landscape and excavated part of a burial mound.
The aim was to build up an understanding of the treatment of the dead during this period and investigate the associated boundary dykes.
The project continues the work of the late Judith Robertson, who undertook a walkover survey across the peninsula and geophysical survey across some of the monuments.
The results of the gradiometer survey (magnetic responses) showed some pit-like anomalies in the mound, and the dykes to the west showed as a series of weak linear trends. The resistance survey (soil moisture) showed high resistance within the mound indicative of rubble or stones. Small trenches and test pits were used to investigate the linear dykes and other geophysical anomalies.
The dykes were constructed from turf placed onto the subsoil and are not prehistoric as previously thought.
The most significant test pit was within a small quarry in the cliff top just to the south of the mound where it appears that the stone for the mound core was acquired. Two quadrants of the mound were excavated. Cist slabs were visible in the base of a large hollow in the top of the mound that were exposed during an unrecorded antiquarian investigation.
This project aimed to assess the extent of previous damage and evaluate the central cist and any associated structures. Removal of the upper layers revealed a series of upright slabs that suggest a complex history of burial. The remains of at least four cists were revealed. These were set into a roughly circular mound of stone slabs that was surrounded by a substantial stone revetment wall.
A small cist, which was inserted into the northern upper part of the mound, was excavated but was found to have been heavily disturbed during the previous investigation. The top slab was missing and only three of the upright slab sides survived, the fourth having been removed.Some cremated bone was found on the basal slab along with some apparently unburnt human bone that may have been introduced within the modern backfill.
This cist is typical of the Bronze Age and probably forms a secondary burial within the mound. Unburnt human bone, including parts of a neonate skull and adult bones, were found in the loose backfill above a rectangular cist in the south-west part of the mound.
This cist also appears to be secondary to the original, central cist and suggests that the remains of at least two individuals were buried there. Inhumation burials are less common in the Bronze Age, when cremation was the usual burial rite. The most remarkable modification to the mound was the construction of a square outer revetment wall around the outside of the original circular wall. The round mound was, in effect, made square.
This wall was constructed from coursed masonry, with an additional revetment wall on the north-west side and some upright slabs on the south-east side. Interestingly, the square outer wall was on the same alignment as the rectangular cist in the south-west side, which may mean that they are contemporary.
The mound seems to have been dramatically refurbished for the insertion of this grave. This cist was not excavated this year and will be investigated next season, however it appears to have been disturbed. Other than the human bone, the most frequent finds were fish and small mammal bones, including the second assemblage of ancient Orkney vole bones on the island, the first being at Outer Green Hill last year, confirming the presence of a more widespread past population.
A single flint flake was recovered, but no pottery was found. In terms of dating, the form and character of the original round mound and cists is typical of the Bronze Age, and could even be late Neolithic in date due to the complexity of central cist uprights. It is possible that it forms some kind of hybrid monument between a late Neolithic chambered cairn and Bronze Age burial mound.
The big question is when was the mound made into a square?
It may not seem much to us today, but the conversion of a round mound into a square one would have been a significant statement in the Bronze Age and there are no other parallels to this in Orkney. It was common for mounds to be refurbished with the insertion of secondary burials, but the construction of a square wall appears to be unique. It is possible that the south-west cist and square wall are much later and could even be Pictish, a period when square architecture was more common. It is hoped that radiocarbon dates of the human bone and continued excavation next year will help clarify some of these questions into the Bronze Age at Cantick.
The project was funded by the OIC and the Heritage Lottery Fund. Thanks go to Eddie Doherty, the landowner.