1994:186 - GLASPATRICK, Croagh Patrick, Mayo

The excavation commenced on August 2, 1994 and was completed on September 16, 1994, a period of seven weeks. A team of six including three archaeologists climbed to the summit each day. The excavation was financed with funds raised locally by the Croagh Patrick Archaeological Committee, the local church and Mayo Co. Council who also provided the digging equipment.

The area investigated was located approximately 25m east of the oratory built in 1905. Initial cuttings in this area revealed the walls of relatively recent stalls and some small finds recovered included some post-1940 coins and religious medals. Two metres further to the east a rectangular dry-stone building, probably an oratory, was uncovered.

The dimensions of the building, which was orientated east-west, were 5.57m east-west x 3.5m north-south internally and 7.76m east-west x 5.52m north-south externally. These measurements and the location of the entrance do not correspond to those recorded by O'Donovan (OS Letters), and therefore the remains of other early Christian buildings probably remain buried on the summit. The south wall and the south-west corner of the building were cut into the natural rock to a depth of 0.7m. As a result the walls in these areas were faced on the inside only, with the other faces starting at present ground level. This gives it the impression of being a 'sunken' building.

The surviving walls varied in height from 1.16m at the inner face of the west wall (northern end) to 0.2m at the inner face of the north wall. The walls were built without the aid of mortar with stones (averaging 0.3m x 0.04m) carefully selected and ingeniously fitted together. The south and eastern walls show evidence for corbelling and probably would have curved into a corbelled stone roof. As in the construction of beehive huts and in this stone building, the slight outward inclination of the bed joints of the stonework directs the rain always to the outside. The completed outline of the building from the outside may have been similar to that of an upturned boat while the internal shape could have been a roughly pointed vault. The only complete survivor of this group of small corbelled boat-shaped structures is Gallarus oratory on the Dingle peninsula.

There was one opening in the building, an eastern entrance 0.68m wide with a slight suggestion of inclined jambs. One would normally expect the entrance in a Christian oratory to be located in the west wall, but owing to the prevailing south-westerlies on the summit of the mountain, the builders may have decided to locate the doorway on the more sheltered east side. On either side of the entrance immediately inside the threshold flag which measured 1.2m x 0.7m were two large postholes one of which was a double posthole (see below).

The stratigraphy within and surrounding the building was as follows. Its walls and interior were covered by a thin layer of topsoil and small stones 0.1m–0.2m thick. Some recent coins, modern glass and religious medals were recovered from this layer. Underlying it was a layer of large stone flags and smaller stones (Context 13). The angle at which they were positioned in the layer would suggest that they represented the inward collapse of the side walls and stone roof of the building. This layer of collapse varied in thickness from 0.22m to 0.52m and small finds recovered from it included some modern glass and fragments of iron. Underlying it in the middle of the building was a large spread of charcoal which measured 3.3m east-west x 1.7m north-south. It was up to 0.34m thick in places and seems to have been divided by a single line of flagstones. Finds from the upper level of the charcoal included some fragments of iron, while a possible worked stone and some fragments of iron were recovered from the lower level.

A dark soil level which included some flagstones and loose stone chips was located underlying Context 13 between the charcoal and the side walls. The surviving remains of Context 19 may represent a floor level of the building. Three sherds of native medieval pottery (13th–15th century), two very corroded bronze pins (a third was found outside the building), some fragments of iron, two worked flints and some possibly worked stones were recovered from Context 19. Unfortunately some modern glass, seeds and a 1971 German coin were also recovered froom it. These modern finds more than likely percolated down through the layer of collapse (Context 13).

Underlying Context 19 on both sides of the charcoal (Contexts 26 and 29) was a peat layer 0.08m thick. Three flints, an animal bone, a possibly worked stone and a fragment of iron were recovered from it. Directly underlying the peat layer was a layer of small stone chips (Context 42) up to 0.1m thick. Underlying this and partly underlying the charcoal was another organic layer 0.08m thick. Between layers of it and the natural bedrock was a layer of gravel up to 0.3m thick at the northern end and 0.1m thick at the southern end. This layer also spread under the eastern half of the north wall of the building, and seems to represent an attempt by the builders to level up this side as the underlying bedrock sloped upwards in a southerly direction.

Two stone-lined postholes were uncovered immediately inside the entrance, one on either side. They were located on the same level as the threshold flag and were cut into the gravel layer and the natural bedrock. The stones lining the postholes were sloped inwards towards the bottom. The posthole on the south side of the entrance was U-shaped in plan and measured 0.3m north-south x 0.24m east-west and was 0.32m deep. One of the two packing stones on the western side of the posthole was curved on one side which may suggest that a wooden post swivelled along the curved edge of the stone. The northern posthole was a double holed one and measured 0.42m north-south x 0.28m east-west (total length) and was 0.3m deep. Both holes of this double posthole were rectangular in plan. An iron object was recovered from the fill of one side while the fill of the other produced an iron nail and a fragment of iron.

Special reports and dating analysis on the finds and soil samples recovered from the excavation are at present being researched in the Archaeological Services Unit in University College, Cork, and these results may throw further light on the dating of the building on the summit of Croagh Patrick. It is hoped that further excavations will take place in 1995 and that more archaeological remains and new dating evidence will be forthcoming from this work.

Castlebar, Co. Mayo