Summary of site:
The landscape of the area between Mountfield and Loughmacrory Hill, including the hills of Mulnafye and Lacht, reflects the involved geology of the Tyrone Igneous Complex which forms the bedrock here. It also contains numerous small, curved ridges, aligned north east/south west that slope into the flanks of the hills. In detail, the ridges consist of merging series of circular mounds up to 500 m long, 40 wide and 10 m high breached by areas of low-lying swampy ground.
They are thought to be moraines from a series of ice fronts of stuttering stability, retreating south west into the Omagh Basin. Moraines are concentrated heaps of debris deposited when the ice front stabilised for a time and the rate of melt was roughly the same as the rate of flow. The breaches are believed to reflect the damage caused by later meltwater coursing through moraines stranded across the main northward flow. Small sections into the deposits show a dominant rock paste of mixed grainsize with some sandstone cobbles carried by the ice from the south.