112 G. H. Kinahan — Re-arranged Glacial Drift. 



on their downthrow sides the drift may be much lower than on the 

 upthrow, on which account the ancient sea beaches are not uni- 

 versally at the same elevation. 



I. — The evidence for this movement is very general throughout 

 the island, as in many places below the 350 feet contour line, and in 

 all places below the 250 feet contour line, the Glacial drift, whether 

 Boulder-clay drift or Moraine drift,^ is more or less washed and 

 sorted into silt, sand, gravel, or shingle. 



II. — This interval • of rest at the level specified seems proved by 

 the raised beaches in places near the coast, and in vallej's between 

 70 and 120 feet above the level of the sea. 



III. — That the land was stationary at this stage is proved by raised 

 beaches and old sea cliffs found at or near the present coast line ; 

 while the subsidence 



IV. is evident from the sub-marine bogs off the coast and the sub- 

 merged bogs and land accumulations under the muds, etc., in the 

 estuaries, lagoons, salt-marshes, and elsewhere. 



The accumulations formed during the time included in Nos. I., 

 II., and III. are very similar in aspect, and may be clays, marls, 

 sands, gravels, or shingles. It does not appear improbable that if 

 properly worked out they might be found to contain different suites 

 of fossils ; this, however, has not as yet been done, and the fossils 

 collected from the different zones have all been grouped together. 

 All the shelly drifts on the east and south-east of Ireland, with the 

 gravels containing chalk iiints on the coast of Cork, have been 

 classed as one, by Prof. Harkness, while it is quite evident that 

 portions of them, at the east and south-east are distinct, and belong to 

 the three different periods, while all the Cork gravels containing 

 chalk flints probably belong to the second or third period, as high 

 up above them in the hills are the remains of the 300 /eef sea beach. 

 The gravels mentioned by Mr. Du Noyer on the coast of Dublin 

 and Louth belong to the second or third period, probably the latter, 

 while those near Howth Harbour seem to belong to the second. 



In the south-east portion of Wicklow, and in the co. Wexford, the 

 marls, sands, gravels, and shingles of the time of the 100 feet 

 beach in general contain fragments of shells ; btit as these drifts 

 are made up of the re-arranged older shelly deposits, much cannot 

 be learned from them, t;nless it shall be proved hereafter that they 

 contain fossils which, do not occur in the shelly drifts of the first 

 period. 



In the central plain of Ireland the gravels of the " Esker sea 

 period," as a rule, are devoid of fossils. These have, however, been 

 found in a few places, as Dr. Oldham, F.E.S., records theru at 

 Finglas, co. Dublin (200 feet) ; Clane, co. Kildare ; Naas, co. 

 Kildare (380 feet) ; between Athy and Castle Comer on the slopes 

 of the high Coal-measure table land ; and at Eoscrea, co. Tipperary 

 (400 feet). Sir E. Griffith has recorded fossils in the drift at 

 Tarmon Hill, co. Mayo (250 feet) ; and the late General Portlock 

 found them in the co. Sligo at 200 feet, and in the co. Londonderry 

 1 Moraine drift, called Boulder drift in my early papers ou the Irish drifts. 



