5th April 2006 - The excavation of the stairwell nears completion at High Pasture Cave

Posted by steven on 05/04/2006 at 09:25 PM

After two weeks of difficult digging and recording, we have almost completed the excavation of the stairwell at the High Pasture Cave site.  Read on for more details.....

Today, Martin Wildgoose became the first person to access High Pasture Cave through the man-made stairwell for over 2,000 years! Time consuming and heavy work in the stairwell finally paid off, revealing over 2.5 metres of standing structure that was built sometime during the Iron Age.

A view looking down into the excavated stairwell with the corbelled side walls and steps visible scale=1m)

The lower fill of the stairwell comprised a brown sediment with charcoal flecks, interspersed between medium to large stone (granite and limestone). However, as we excavated the sediments immediately above the treads of the stairs we found fragments of animal bone and a few sherds of pottery, while the amounts of charcoal also increased. With depth, we started to uncover large lintel stones, some of which were around a metre in length. Most of the lintels were found to be pointing vertically into the fill of the entrance and are most likely the roofing slabs that once covered the man-made entrance. A structural failure of the east wall of the stairwell during prehistory had caused the collapse of the roof, after which the structure had been backfilled with rubble and soil to the surface.

A view from inside the entrance looking at the lower series of steps, some of which are tilting alarmingly to the west

After removal of the collapsed lintels from the stairwell, we found more random boulders and stones, and more isolated pockets of sediment. After we had uncovered the 10th step in the structure there appeared to be a vertical drop of around 0.75 metres and the archaeological deposits here were found to contain more charcoal, animal bone and pottery. This dramatic change in the context indicated that we had reached a layer of deposits that was very similar to the upper contexts of archaeological fill in Bone Passage. As the day progressed, and the weather deteriorated significantly, we started to excavate the remaining deposits of fill in the base of the stairwell from inside Bone Passage. Looking out from below the natural limestone roof of the cave, the view up the stairwell is quite dramatic with the inward corbelling side walls and the steep flight of steps.

By the end of the day, we had excavated a significant amount of fill from the entrance revealing an opening some 1.8 metres wide and 0.75 metres high. We also uncovered three more steps at the base of the stairwell and other structural elements that will have to be exposed and investigated further tomorrow.

A view down into the stairwell from the south with the arched entrance into Bone Passage visible towards the bottom, penetrating the natural limestone bedrock (scale=1m)

Next entry: 10th April 2006 - Iron Age entrance re-opened at High Pasture Cave

Previous entry: 27th March 2006 - Visual connection made between the stairwell excavation and Bone Passage


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