part 3] GLACIATION OF NORTH-EASTERN IRELAND. 369' 



the neighbourhood of Bally mena, and probably still farther south, 

 although the traces of this further movement have been removed 

 by a later glaciation from the south-west. 



At a later stage, while considerable quantities of ice were still 

 passing from the north-east down Glenravel, the pressure of the 

 northward-moving ice, in the great central depression occupied by 

 the valley of the River Main and that of the River Bann, had 

 so far increased as to turn the Glenravel glacier northwards, round 

 the spur of Slieverush, near Newtown Crommelin. 



This movement is indicated by the direction of the axes of the 

 numerous drumlins (consisting of reddish gravel, which contains, in 

 addition to the local basalt, considerable quantities of schist and 

 gneiss) between Ballynagaboy Bridge and Corkey, and by the 

 drainage-channels which fall north-westwards. These include a 

 channel at 950 feet above O.D. cut through the basalt-spur north 

 of the Aghanageeragh River, and a much larger winding valley 

 (at 750 feet) cutting the spur of Slieverush near the cross-roads, 

 2 miles south-east of Ballynagaboy Bridge. 



The valley of the Skerry Water above Newtown Crommelin 

 contains large quantities of basaltic gravels and boulder-clay with 

 no erratics, and was probably occupied (at all events at a late 

 stage) by a glacier from the great snowfield in the triangle between 

 Trostan, Slievenanee, and Eagle Hill, already mentioned (p. 366). 



The northern flank of the Glenravel glacier is marked by a series- 

 of channels on the line of the mineral railway from Parkmore to 

 the ironstone-mines near Ballynahavla Bridge at 1050 feet O.D.,. 

 north of Tuftarney Hill at 850 feet, and two parallel channels at 

 960 and 940 feet respectively, through the spur of Skerry Hill 

 which terminates in the bold escarpment of the Skerry Rock above- 

 the village of Newtown Crommelin. 



The direction of the ice-flow is shown by the striations on a sill 

 of dolerite at Tuftarney Hill. 



The Southern Area (see map, fig. 4 } p. 370). 



The rivers flowing down the seaward slope are the Carnlough 

 River, the Glencloy River, the Glenarm River, and several smaller 

 streams farther south, including the Larne Water, the Glynn 

 River, and the Woodburn River. The western slope is drained by 

 the Braid River, the Glenwhirry or Kells River (both tributary 

 to the River Main), and by the Six Mile Water and its tributaries 

 flowing into Lough Neagh. 



The valley of the Carnlough River is very deep and gorge- 

 like, and contains a fine waterfall. Its flanks are thickly covered 

 with boulder-clay and gravel up to 1000 feet above O.D. This drift 

 rests upon basalt, and contains boulders of basalt, flint, and chalk, 

 the two last-named having been carried up the valley from the 

 Cretaceous outcrop between the 200- and 300-foot contours. 



The upper part of the Carnlough River is known as the Cranny 

 Water, and at its head (at 1075 feet O.D.) is a broad and deep 



