238 Mr. G. Tate on Glaciated Bocks. 



7. In the account given by me of the geology of the Fam 

 Islands, in the Proceedings of the Club, Vol. III., p. 223, it 

 is stated that, " on these islands are patches of the boulder 

 formation, which covers many parts of Northumberland ; it 

 forms the sub-soil of the Farn, and on the Stapel it is three 

 feet thick overlying the basalt." Subsequently to the Meet- 

 ing of the Club at Abb's Head, I revisited these islands with 

 the view of searching for traces of ice action ; and on the 

 Stapel Island, the most favourable for observation, I found 

 the surface of the basalt smoothed and striated over consider- 

 able areas ; so much so, that it is pretty certain that the 

 whole island had been subject to ice action. The boulder 

 clay, which had covered the whole, has been denuded from 

 many parts ; but still, excepting where the dashing of the 

 waves has broken the surface, smoothed and striated surfaces 

 are traceable even along the sea-shore. From some other 

 parts I dug away the covering of boulder clay, and found 

 dressings and striations in a more perfect state, and resem- 

 bling those on the porphyry at Abb's Head. The direction 

 of the strise is from N.N.W. to S.S.E. 



8. I have never succeeded in discovering organisms in the 

 boulder clay in the eastern borders ; but Mr. Richard Howse, 

 in an able paper printed in the Proceedings of the North of 

 England Institute for 1864, giving a description of glaciated 

 rocks near the mouth of the Tyne, records the discovery in 

 the boulder clay at Tynemouth of small pieces of Cyprina 

 Islandica, a marine shell, which is common enough in the 

 seas off the Northumberland coast in a living state. Con- 

 firmatory of this, is the observation of Mr. Binney, of Man- 

 chester, who informed me in 1864, that he had detected 

 several fragments of this shell in the boulder clay near 

 Tynemouth. The discovery is important ; for if it can be 

 extended to other localities, it would throw doubt on the 

 view originally proposed by Agassiz, and revived recently 

 by some geologists, that the polished and scratched surfaces 

 and the accumulation of the boulder clay were produced by 

 the movements and abrasion of sub-aerial glaciers and land ice. 



9. Glaciated blocks in the boulder clay have been observed 

 more frequently than glaciated rocks in situ. They may be 

 found in most good sections of this clay. The eastern part 

 of Northumberland especially, from the coast to the flanks of 

 the hills, is much covered with it. Numbers of glaciated 

 blocks were exposed when cuttings were made through 

 deposits of clay, gravel, and sand, for the railway between 



