256 



Mr. Lyell on the Cretaceous and Tertiary 



(fio-. 11.). Two rents are seen descending perpendicularly downwards from the surface of the 

 country, and terminating the one at the depth of about 100, and the other at more than 150 feet 

 from the top of the cliff. They are filled with sand, and near their termination are two caves, 

 a, h, partially filled with sand, one of which is fourteen and the other sixteen feet high. These 

 caves, which may be sections of long subterranean passages, are distinctly connected with dis- 

 locations in the chalk, some of which could not be seen from the point of view where the sketch 

 (fig. 1 1 .) was taken. 



Fig. 11. 



^^^ 



View of the Cliff called Dronningestolen, Island of M den. 



a. h., Caves. 



Without entering further into local details, I may state, that wherever in 

 Moen masses of sand and clay are included in the midst of the chalk, a con- 

 nection may be traced between them and the upper surface of the cliff by 

 lines of fracture in the chalk, usually filled with similar sand and clay. 



A few apparent exceptions will naturally occur, in consequence of that re- 

 moval of rock by which the cliffs were formed ; but we may suppose that such 

 insulated patches of clay as are represented in fig. 10 may have been prolonged 

 upwards towards the summit of chalk, which has been carried away on the 

 side of the sea. 



I have already stated that the ravines descending to the sea coincide in 

 position with great lines of fracture, and the various phenomena of the in- 

 tercalation of clay, sand, and gravel in the chalk, and the entanglement of the 



