Palceosoic Rocks of Oahvay and elseivhere in Ireland. 353 



From the diagram and this general section, it will be seen 

 that to the north and south of the curve the succession of 

 the groups is similar, although the groups differ in thickness ; 

 while the sections across Bennabeola and the Corcoo-emore 

 hills (Plates XXXI. and XXXII.) explain the present conditions 

 of the groups ; all the strata being more or less moved from 

 their normal positions by the numerous faults that traverse the 

 area in various directions. 



From the section across Bennabeola, we learn that the great 

 nearly E. and W. fault of the Clifden and Oughterard valley brings 

 down the rocks of the Middle micalite series (B 7) against those 

 of the Quartzitic micalite series (B 3), thus cutting out the inter- 

 mediate groups, besides inverting the dip of the strata to the 

 south of the fault. Here the order of the rocks is very much 

 confused by the displacements due to this and other faults ; the 

 rocks of the Great quartzite and associated series being con- 

 cealed in the country to the south of its line ; but if we go further 

 eastward to Lissoughter and to the Corcogemore hills, we find 

 the Ophiolite, 8mall micalite and Great quartzite series (B 4, 

 B 5, and B 6) lying on the ridge of the anticlinal curve, and 

 dipping both to the northward and southward under the 

 younger groups. The section to the southward is very com- 

 plete, as only the Small quartzite series (B 9) and part of the 

 Ballynahinch series (B 8) are concealed by the Clifden and 

 Oughterard fault, while all the rocks dip regularly southward. 



Elsewhere, as in the Geological Survey Memoir and the 

 "Geology of Ireland," I have divided the metamorphic rocks 

 into the Gneiss series, the Schist series, and the Submeta- 

 TYiorphic series. If the county is traversed from Clifden south- 

 ward to BalJyconneely, the rocks are found to belong to the 

 " Schist series ;" but the metamorphism probably decreases 

 southward ; because to the south-east and south, of a portion of the 

 excessively metamorphosed rocks, in Lettermullen and Gorumna, 

 the rocks of the Lettermullen series (B 12) are only submeta- 

 morphic. 



If from the schists between the Clifden valley and Ballycon- 

 neely, we proceed eastward along their strike, they are found to 

 graduate through gneiss into granite ; this, however, does not 

 take place suddenly, as before the main mass of the metamorphic 



