Reviews — TF. C. Lucy on the Gravels of the Severn, etc. 31 



swept away at the time. At this period, he believes, the Oolite 

 probably extended over the New Eed Marl to May Hill and Malvern. 



The apparent absence of Chalk flints from the higher patches of 

 Northern Drift seems to indicate that the Chalk was not then in a 

 position in this part of the country to furnish materials for the 

 gravel. Mr. Lucy's observations lead him to conclude that the 

 denudation of the Cotteswolds took place early in the Glacial 

 period ; whereas, as he mentions, Professor Ramsay seems to be of 

 opinion that the Valley of the Severn existed prior to the Glacial 

 period, because Glacial deposits are found in it as far as Tewkes- 

 bury. When the Severn Valley was originally formed the Professor 

 admits it is ditficult to say, although England, having probably been 

 above the sea during the greater part, or perhaps the whole of the 

 Miocene epoch, it is likely that some of our- great contours were 

 then first begun, or, if not begun, carried on and very seriously 

 modified. 



We have not space to discuss at length Mr. Lucy's account of the 

 origin of the Gravels. They appear to show alternations in the 

 level of the country, commencing with the deposition of the Pebbles 

 at the highest level when the land was beneath the sea, and giving 

 evidence in the valleys of the High- and Low-level Gravels due to 

 river-action, and of another encroachment of the sea, which is 

 evidenced by the presence of marine shells in .some of the Lower 

 river Gravels. Here and there evidences of ice-action are met with. 



Commencing in the Glacial period, and marking stages in the 

 denudation of the country, the deposition of Gravels continued long 

 after its close. 



Their separation into " Northern Drift " and Oolitic Gravel, 

 appears, so far as we can understand, to rest merely upon the com- 

 position of the Gravels, and does not mean that any distinct agencies 

 need be invoked to account for them. 



Some of the Gravels appear to be of marine origin, others of 

 fluviatile, but the distinctions are not marked upon the map. 



The term "Northern Drift," as Mr. Lucy acknowledges, is not 

 altogether satisfactory. But he uses the word "Drift" (in speaking 

 of the Oolitic Gravel also) to denote all those superficial accumula- 

 tions of transported materials, which cannot have been produced by 

 the tranquil causes which are in daily operation in the district. 

 Much yet remains to be done in determining the exact boundaries of 

 the superficial deposits over the Valleys of the Severn and its tribu- 

 taries, and indeed Mr. Lucy remarks that several points of con- 

 siderable interest and importance require to be dwelt upon more 

 fully to complete the subject. So that while all geologists will 

 thank Mr. Lucy for what he has done, they will hope at a future 

 time to have some further contributions from his pen. 



Mr. Lucy alludes to the earlier writings of Murchison, Strickland, 

 Buokman, Hull, J. Jones, Witchell, Symonds, and Maw, and we may 

 mention that subsequently to the reading of his paper before the 

 Cotteswold Club, a communication on the same subject was made to 



