7th - 10th June 2005 - Superimposed Hearth Settings uncovered in Trench 2

Posted by steven on 13/06/2005 at 01:37 PM

A fine week of weather allowed us to make good progress at the High Pastures site. Read on for details of what we have found in the trenches, including some new finds.

Excavation of Trenches 2, 3 and 4 have continued on site during the past week, with some excellent weather conditions. A good breeze on site has also resulted in no problems from our wee biting friends - the Scottish midge!

The image above shows George Kozikowski excavating a post hole in Trench 3, immediately outside of the entrance to the roundhouse. Unfortunately, no dating material for dating this feature was found, although several small sherds of pottery were recovered from a compacted, charcoal-rich ground surface in the entrance to the roundhouse. A mass of dumped stone complete with open voids was uncovered between the entrance to the roundhouse and Trench 2, which requires further investigation.

Elsewhere on site, Ann and Mike Kibby completed the excavation of Trench 4, which is located on a flat grassy platform to the east of Trench 2. The platform has a boulder-built wall running along the north and east sides, while a possible archaeological feature was identified during the geophysical survey undertaken by Stratascan Ltd. A 2m x 1m trench was excavated in the centre of this platform. Although the upper contexts of the trench revealed quite sterile layers of soil, a linear feature comprising compacted stone was located some 0.6m below the turf line. Small fragments of charcoal were recovered from the sediments above this feature, while several pieces of fire-cracked pebble were found in the compacted layer of stones. Several pieces of highly magnetic rock were also recovered from this feature, along with a lump of iron-rich slag. This suggests once again that metalworking was taking place at the High Pastures site in the past.

Otherwise, no other finds were made in this trench and after recording had been carried out by Ann and Mike, the trench was back-filled for this year. The grass-covered platform will be investigated further during fieldwork at the site in 2006.

The image below shows Trench 4 after excavation, with linear feature (NW-SE axis), comprising a fill of compacted stone, visible in the bottom.

The trench is shown from the east below. The stone-built feature has been sectioned to investigate if a cut could be identified in the soil below.

The excavation of the Trench 2 extension has also progressed well, although removing a 2m x 2m extension from a 3.2 metres deep section proved a labour-intensive task and one we hope not to have to repeat too often!

The plan above shows the location of the Trench 2 extension, the excavation of which should allow us to access the original entrance into Bone Passage of the cave. The extension to the trench allowed us to revisit contexts that we had originally uncovered in the main section of Trench 2, and permitted more samples to be taken of soils and sediments.

One early discovery in the trench was an alignment of limestone slabs forming a possible revetment wall, although this only comprised a single course of stone. At the level at which the wall was uncovered it provided a clear boundary division between the brown soils adjacent to the roundhouse (the same sediments uncovered in Trench 3) and the dark, organic-rich sediments comprising the fill of the hollow above the former entrance into the cave. Steven Birch can be seen kneeling on the exposed limestone slabs excavating the dark sediments, while George Kozikowski can be seen beyond excavating in Trench 3.

As we excavated deeper through the sediments above the entrance into the cave we uncovered a series of superimposed hearth settings, suggesting that this part of the site may have had some special significance in the past. The image below shows the extension to Trench 2 under excavation, with the limestone slabs of the revetment wall at the top. 

In the image the small scale (0.25m) is located immediately below the hearth slabs of the top setting while a second hearth, still to be uncovered at this stage, is situated just below the level of the larger scale in the image (2.0m). The position of the third hearth is indicated by the sequence of ‘domed’ coloured lenses below.

The image above shows a view looking down onto the surface of the top hearth setting, which is manufactured from two granite slabs of rock. The stratigraphy around the hearths is very complex with intricate lenses of peat ash and charcoal-rich sediments, from which samples were retrieved for detailed analysis by soil specialists. We also recovered fragments of burnt bone, burnt hazelnut shells and charred grain from these features.  Un-burnt bone was also recovered in increasing quanities as the trench became deeper, possibly due to improved preservation at this depth.

The image above shows the complex stratigraphy in the Trench 2 extension, with the lower hearth (feature F210) under excavation. We sectioned this feature to show its extent and morphology, removing each context and photographing the results as we proceeded. The feature was remarkably preserved and must have been buried quickly after its formation, while the contexts making up the feature were found to run into the baulk of the trench at the rear. The deposits from the hearth were found to be lying on top of a very large granite slab of rock, which is almost level, while below this we found other structural stonework that will be investigated during our next day on site.

Feature F210 (hearth setting) is shown under excavation above, the scale resting on the granite slab forming it’s base. Immediately to the right of the feature are a series of slabs lying at a steep angle, which are resting directly on top of each other. We now believe this to be the remains of corbelling, a type of construction technique utilised in forming a roof over a stone-built structure. Similar types of construction technique can be seen in chambered tombs of the Neolithic Period, while in the Iron Age sites such as Mine Howe in Orkney display this intricate method of forming a roof.

Considering the potential depth we still have to excavate in this trench, which is up to 1.5 metres below the white slabs in the image above, the corbelling may have formed the roof over an elaborate entrance into the natural cave passages beyond. Although the structural elements seem to be fragmentary at this level in the trench we hope that the passage below will be intact, allowing us easier progress into Bone Passage.

The only artefacts recovered so far from the excavation of the Trench 2 extension is a large piece of red deer antler beam that shows evidence of having been cut, a large lump of ironworking slag that was recovered to the side of one of the hearth settings, and a fine polished bone point complete with a small spatula on the opposite end to the point. For digital images of these finds see the most recent entry in the latest finds page.

Next entry: Trench 2 extension reveals more finds

Previous entry: Torrential rain results in some delay in progress at the High Pastures site


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