The deposits of the Pomeroy deglacial complex are located at the southern margins of the Sperrin Mountains and record complex evolution during deglaciation. An ice sheet which covered this area and the highland areas further north split into two lobes during the final stages of deglaciation upon entering this area during backwastage into the source areas of the Lough Neagh lowlands and the Omagh basin. Ice marginal deposition combined with bedrock topography resulted in the formation of an extensive subaqueous fan, high level Gilbert-type deltas (at 245m O.D.), extensive outwash plains and terraced valley-fills. An example of classic hummocky and ridge topography is located near Pomeroy. Ice pressure from the southwest (Omagh basin around Clogher) is indicated by a distinctive sandstone conglomerate contained in the complex and a glacially moulded bedrock knoll to the northwest of Carrickmore which shows ice flow direction to 120°N. The complex contains a wide range of deglacial landforms including proglacial, paraglacial, subaqueous and subglacial deposits. The area is 118km2 in extent and stretches from Sixmilecross [H570 679] to Galbally [H722 659] and from the southern margin of the Cregganconroe / Evishanoran highlands [H657 751] to the Owenbrack river valley [H613 726]. The deglacial features include: the Ballynapoll fan between Aghnaheragh [H636 716] and Crockroar [H657 719], Tremoge moraine-ridges from Tremoge [H658 729] to Rockstown [H623 727], Altanagh moraine [H624 699], Sluggan outwash [H653 706], Edenfore delta and Owenbrack outwash between Cranlome Hill [H659 639] and Lurganmore [H635 630], Pomeroy moraine between Limehill and Pomeroy forest [H706 727], and flat-topped terraces and dissected deposits at Altmore [H682 679] and Galbally [H723 663].
