282 Reports and Proceedings — Oeological Society of London. 



that the sequence is somewhat as follows (beginning from the 

 centre : — 



(i) Coarse-grained ophitic dolerite, forming the greater part of 



the mass, 

 (ii) Fine-grained ophitic dolerite, say 10 to 20 feet from the 



margin, 

 (iii) Basalt with very little augite, and with rods of iron-oxide. 

 (iv) Basalt with porphyritic plagioclase-crystals in a groundinass 

 of microliths of plagioclase and hairs and rods of iron- 

 oxide, having no augite. This occurs as near as ^ an inch 

 to the junction, and as far as 5 inches away from it. 

 (v) Basalt with porphyridc plagioclase in a gray groundmass, 



say vo to 1 inch from the margin, 

 (vi) Basalt with poi'phyritic plagioclase in a groundmass which is 

 sometimes spherulitic ; about -^-o inch thick on the average. 



2. " Notes on some Eailway Cuttings near Keswick." By J. 

 Postlethwaite, Esq., F.G.S. 



Several cuttings have recently been made on the Cockermouth, 

 Keswick, and Penrith Railway, chiefly through drift, though some 

 occur in the Skiddaw Slates, and in one case a diabase dyke (much 

 decomposed) was met with. 



The author describes the drift as blue clay beneath, and brown 

 clay above, and considers that these two clays were produced during 

 two separate periods of glaciation, with no long interval between. 

 In some places near Keswick water-boi'ue gravel may be seen 

 surmounted by blue clay ; this gravel is considered by the author 

 to be of fluviatile origin. 



The author has searched both blue and brown clays diligently for 

 shells, but hitherto without success. 



3. " The Shelly Clays and Gravels of Aberdeenshire considered 

 in Relation to the question of Submergence." By Dugald Bell, Esq., 

 F.G.S. 



The drifts of this region have been described by Mr. Jamieson, 

 and also in the publications of the Geological Survey. The two 

 authorities agree that the Lower (gray) Boulder-clay of the district 

 was produced by a local glaciation. The Geological Surveyors, 

 however, maintain that the intervening sands and gravels with 

 marine shells were produced during a submergence of 500 feet or 

 upwards, whilst the Upper (red) Boulder-clay was formed by an 

 ice-sheet from the south. Mr. Jamieson, on the other hand, assigns 

 a purely glacial origin to the Middle Sands and Gravels, and con- 

 siders that the Red Clay (which contains a few fragments of marine 

 shells) indicates a submergence. 



The author discusses these views, and maintains that submergence 

 is not proved in the case of either Middle Gravels or Red Clay, but 

 that the former are, as Mr. Jamieson maintained, truly glacial, 

 whilst he advocates the existence of extra-morainic lakes to explain, 

 the latter. 



