352 G. H. Kvnahan — Dingle and Olengariff Grits. 



the Kerry Head and Tralee districts the " Old Eed Sandstone " is 

 more or less conglomeratic ; this is also the case near Douglas Head 

 in the west portion of the strip south of Dingle Bay, while eastward 

 thereof it gradually loses this character, and near Killarney it presents 

 more of the usual Cork type. The Cork type, however, changes as 

 the rocks are followed eastward, and in Waterford, 1 Tipperary, and 

 Kilkenny, conglomerates are again found. 



In S.W. Kerry and W. Cork the sequence of the rocks, as laid 

 down by Griffith and Jukes, is as follows : — 



Carboniferous Slate (6) 



Yellow Sandstone or ( ( 5 ) %™^< F e J> and X eUo ^ &**, with shale P artin S 

 Urraer Old Eed i containing grass-like plant-remains. 



1 v [ (4) green, red, and liver-coloured slates. 



I (3) purplish and green grits, and slates, many of the 

 Old Red Sandstone 1 green rocks being cupreous. 



( (2) red and purplish grits, gritty slates, and slates. 

 Glengariff grits (1) 



As strata representing the groups 2, 3, 4, and 5, occur everywhere 

 in this area under the Carboniferous Slate, it is perfectly impossible 

 that in any place there can be an unconformity between the 

 Glengariff Grits and the Carboniferous Slates. These facts in 

 reference to the Kerry and Cork rocks have already been mentioned 

 elsewhere; it is however necessary to draw attention to them again, 

 on account of some misapprehension on the subject still existing. 



Subsequent to the end of the Carboniferous Period, a great rupture 

 (besides others) took place along the line of the valley of Dingle 

 Bay, and further eastward in the Flesk and Blackwater valley, 

 which evidently was a downthrow to the northward. However, it is 

 readily conceivable that here, as elsewhere along great lines of dis- 

 turbance, a newer displacement along the same line of weakness need 

 not by any means have necessarily the same horizontal extent, any 

 more than it should have the same amount of vertical throw. This 

 Post-Carboniferous fault, which may have been on the same line as 

 an older one, has a northward downthrow, in some places of greater 

 magnitude than in others. Near Millstreet it seems to bring down 

 the Coal-measures against the Glengariff grits, but eastward of this 

 the throw is much less, while westward for some distance it also 

 decreases ; but after a time it again increases, as we proceed toward 

 Killorglin, where it possibly may again bring down the Coal- 

 measures against the Glengariff grits ; but farther west it decreases. 



I would refer to the fossils found in the Dingle beds and Glen- 

 gariff grits ; as statements made in reference to them are calculated 

 to mislead. No officer of the Geological Survey of Ireland who 

 lias examined the rocks in which the fossils are found has suggested 

 that the rocks are Coomhoola grits or Carboniferous slate. There 

 is no doubt as to the localities in which the fossils were found. 

 Some of them are far from being obscure. 



In the Dingle beds, north of Dingle Bay, there are more or less 

 obscure markings in various places that may be due to either land 



1 I suspect that some of the Waterford rocks, at present supposed to be " Old Eed 

 Sandstone," will eventually have to be included among the Dingle beds. 



