Summary of site:
In the Templemoyle area of the upper Owenrigh River there are fragments of a glacial lake delta, extending from the confluence of the Altnaheglish River with the Crooked Burn in the east, to Mullaghearn, with hummocky deposits on the lower, north-east slopes of Mullaghash, 3km to the south west. Sections of the delta deposits reveal sands and pebble gravels with their front faces inclined 20-25º to the north. The deposits thin on to the flanks of the surrounding hills. The original lake surface was near the modern 200m contour.
The fragments became isolated by vigorous meltwater channels that cut down to bedrock after the lake had drained northwards into the Roe Valley. These channels are now the Cushcupal Water, the Crooked Burn and the Altnaheglish River.