154 The Irish Naturalist, 



jointed, and is traversed by some well-marked fault-planes. 

 In some places it appears to be slightly foliated, and the joint- 

 planes contain chloritic matter. Near the end of the cutting, 

 the granite approaches the character of a breccia. Through 

 a considerable part of the cutting, the rock is covered with a 

 layer of peat containing numerous tree-roots. 



On emerging from this cutting the line runs for over a mile 

 through bog. At the farther end of the bog, on the right- 

 hand side of the railway, is a lead mine, from which a 

 considerable quantity of ore was raised. The works have 

 long been abandoned, and are now full of water ; but a full 

 description of them may be found in the survey memoir' of 

 the district. In the rock cast from the mine some good 

 specimens of barytes may be found. 



About a mile beyond the mine some protrusions of horn- 

 blende schist have been cut through on the right of the line. 

 This schist contains well-developed crystals of hornblende, 

 probably due to secondary crystallization. At one place a 

 lump of epidote, about three inches in diameter, may be seen 

 in the schist. 



At the bridge over the river, near the village of Garabaldi, 

 are white crystalline limestones with strings of chloritic 

 matter, which give them a schistose appearance. 



Between the river bridge at I^eam and the road-crossing 

 are hornblende schists with some limestone. Crossing the 

 railway, cutting the limestone and schist, is a narrow dyke of 

 basalt. The surface of the schist at this place is often ice- 

 polished, and .shows very prettily the curled and contorted 

 foliation. 



Cuttings ai,ong I^ough Bofin. 



Opposite the south end of the lake are hornblende schists 

 with quartzitic bands. Farther on are schists with granite 

 veins, which contain large flakes of silvery white mica. 

 North of the island are quartzites, some of which are very 

 coarse-grained and schistose. The quartzite is often cut by 

 granite veins. In one place the granite seems to graduate 

 into eurite ; but Professor Cole, on microscopic examination, 

 finds the supposed eurite to be a fine quartz-breccia, with very 

 few evidences of felspar. 



^ Memoir of Geol. Survey of Ireland to sheet 95, p. 65. 



