Kinahan — On Granite and Metamorphic Rocks. 227 



sedimentary rock, as it graduates on the one hand into schist, and on the other into 

 metamorphic granite. This, however, is not the case in regard to the rock now being 

 described ; as although foliated, and having its foliation in the same planes as that of 

 the associated rocks, yet it is evidently an intruded rock, as it has well-defined, sharp 

 boundaries at its various exposures.] 



It has been pointed out by Symes that this rock could be raised, 

 in some places, in blocks of very great size ; but it works badly 

 across the foliation, and is therefore not very suitable for cut-stone 

 purposes. Wilkinson states "the rock is even-grained, but hard 

 and difficult to cut ; seldom used for any purpose, as there is very 

 little demand for it in the immediate neighbourhood, and the lime- 

 stone and sandstone are abundant in other parts. In a few places 

 in roads, bridges, and common walls it has been used in the way in 

 which granite is commonly employed, being split for rough-shaped 

 quoins and common walling, and no dressing being necessary, it 

 has proved sufficient for such purposes. Large blocks could be 

 obtained, and it appears to be an even-textured stone, although the 

 quality varies along the boundary of the district." 



The granite has been very generally utilized in local County 

 works : for instance, the Pontoon Bridge and Hotel were built of it. 



Whinstones. — Intrusions of this rock occur in the schist area in 

 the following localities, viz. on the north-eastward side of the 

 Lough Easky granite ; also four miles N.E., and about the same 

 distance W. of Lough Cullin ; also over three miles N.E. of 

 Castlebar, and at Derrycoosh, W. of the same. Whinstones occur 

 in the Carboniferous Limestone, in the valley of the Moy, close to 

 the S.E. margin of the schist, and to the north-east of Turlough ; 

 and (in a very long narrow strip) near Castlebar ; and (similarly) 

 near the village of Cushinsheeaun ; and about three miles S.W. of 

 Westport. 



In general these stones are excellent for road metal, or as large 

 blocks for foundations, or other similar rough work ; the Cushin- 

 sheeaun course is cut by the Great Midland Eailway, and stone 

 *rom it was brought by that Company to Dublin for such purposes, 

 when they were constructing the Spencer Dock ; but the stone of 

 the long course, near Castlebar, weathers to a considerable depth 

 into a coarse sand, and is apparently the same class of rock as the 

 " Bohernacolley " rock of N.W. Gralway. This detritus, as has 

 been mentioned, should be useful as a fertilizer. 



