2002:1377 - BROADHAVEN BAY, Mayo

Three magnetic anomalies were identified in the intertidal zone during a pre-development survey. These anomalies lay on or near to the route of an underwater gas pipeline trench. Test excavations took place on 10 July 2002. Three test-trenches, 6m long and 2m wide, were excavated using a tracked excavator with a flat bucket.

The northernmost anomaly was tested first, the sand being removed in thin layers. This trench was aligned north-west/south-east. A large quartz boulder was encountered directly below the surface, immediately adjacent to the peg inserted to mark the location of the anomaly. This may have been the source of the strong negative reading attained here. Below this, bedrock was encountered at a depth of 0.45m. Nothing of an archaeological nature was encountered.

Trench 2, aligned north–south, tested the central anomaly. Again, the sand was removed in thin layers. Sandstone bedrock was encountered at a depth of 0.6m. Nothing of an archaeological nature was encountered.

Trench 3, aligned north–south, tested the southernmost anomaly. The sand was removed in thin layers. Bedrock was encountered at a depth of 0.55m, and nothing of an archaeological nature was encountered.

The sand removed from each of the trenches was spread by tracked machine to a depth of c. 0.3m. A temporary grid was laid out, and the spread material was systematically walked with a metal-detector. Nothing of an archaeological nature was recovered.

No archaeological features or finds were noted or recovered during excavation or metal-detection. It seems likely, therefore, that the high negative readings recorded during the magnetic gradiometer survey have a geological origin, the quartz boulder encountered in Trench 1 being one likely cause.

3 Canal Place, Tralee, Co. Kerry