554 Prof. G. A. J. Cole — Destruction of Chalh. 



winter of 1894—5, and tlieir effects upon the coast of County Antrim, 

 may teach us an important lesson in the destruction of the Chalk by 

 more ordinary natural causes. 



The constant landslips at Garron Point and near Glenarm have 

 given rise to a number of masses of chalk, overriding and embedded 

 in the deposits of the present sea, so that the coast, w^ere it upheaved, 

 could with difSculty be differentiated from that of Cromer. The 

 modern sands of the Channel are here mingled with the debris of 

 glacial "drifts," which contain the fragments of shells that marked 

 a colder period. A singular confusion of materials could thus be 

 dredged up close to the land, and blocks brought by floating ice 

 from a distance, such as the eurite of Ailsa Craig, are familiar objects 

 upon the shore. These latter may repi'esent, on the scale ot our 

 Antrim illustrations, the Norwegian rocks in the drift of Cromer. 



The great storms of the last fortnight of December, 1894, added 

 a large portion of the coast-road to the modern " drift " deposits of 

 the Irish Channel ; and they have also provided us, on the north side 

 of County Antrim, with an effective model of the newly discovered 

 floor of Huntingdonshire. 



I am indebted to Mr. E. Welch, of Belfast, for a description of the 

 scene in Whitepark Bay, between Carrick-a-rede and the Giants' 

 Causeway. The Chalk and the Greensand here rest characteristically 

 upon the Lower Lias, the clays of the latter series providing the 

 former with an easy gliding-plane. Doubtless the shore for some 

 distance seaward is formed of detached masses of the Cretaceous 

 strata; but the storm-waves have now swept clear from sand an 

 area of, on an average, 1000 feet by 100 feet, its width at the 

 centre being about 250 feet. Mr. Welch has, as usual, made a 

 very successful photographic record of the rocks exposed (No. 5119 

 in his geological series). The whole area is seen to be covered 

 with blocks of chalk, which are often 10 feet long ; they are almost 

 in contact, and are bounded above and below by their planes of 

 stratification, like flakes that have been moved only a short distance 

 from their original position. In the cleft-like intervals between 

 them, the dark surface of the Lias clays is everywhere visible. It is 

 as if a massive bed of chalk had been broken up almost in situ ; and 

 we probably have here a picture in miniature of many miles of the 

 submarine coast of County Antrim. The spaces between the blocks at 

 Whitepark Bay will, in time, become filled up with modern beach- 

 material ; and we onlj' want floating ice in the Channel to embed 

 them in a glacial sand or in a Boulder-clay. Their environment 

 will be a shifting material, liable to compression and even to con- 

 tortion, as new masses ooze out slowly from the land. Mr. Welch's 

 photograph thus seems to reveal to us what we may call a land- 

 slide-phase, rather than a catastrophic landslip-episode, in the 

 destruction of the Chalk. I venture to think that it represents an 

 early phase in the history of the huge chalk-flakes and associated 

 drifts that are being studied in England by Mr. A. C. G. Cameron. 

 The picture is a striking record of the way in which massive chalk may 

 go to pieces, and may be moved outwards on a gentle slope, while 

 yet preserving its stratified aspect and a certain air of continuity. 



