4 GEOLOGY. 



there is no unconformit}", nor even a sharp junction. [See Hicks, 

 p. 16.] W. H. D. 



Barrois, Dr. Ch. Recherches sur le Terrain Cretace superieur de 



I'Angleterre et de I'lrlande. [Upper Cretaceous of England and 



Ireland.] Mem. Soc. Geol. Novel, pp. 234 ; 3 plates (maps and 



sections), many woodcuts. (A Summary in Ann. 8oc. Geol. Nord, 



t. iii. pp. 189-205.) 



Points out the insufficiency of previous descriptions of the Chalk in 



Great Britain, and indicates the general distribution of the beds. 



Chap. 1 treats of the Hampshire Basin, the first sections being severally 



occupied with its E., N., W., and S. divisions. The second part of this 



chapter gives an account of the earth-movements, both contemporaneous 



with and subsequent to the deposition of the Cretaceous beds, the lines 



of elevation being also compared with those of the Paris Basin. Chap. 2 



refers to the London Basin ; a detailed description of the beds is given, 



and the causes of the variations in their thickness are discussed. Chap. 3 



describes the Chalk of Lincolnshire and Yorkshire, and compares it with 



that of the N.W. of Germany. Chap. 4 treats of the Irish Chalk, in 



which are found representatives of all the Cenomanian, Turonian, and 



Senonian zones. A tabular view of the zones identified in the diff'erent 



districts concludes the memoir. A. J". J-B. 



L'Age des " Folkestone Beds " du Lower Greensand. [Age 



of the Eolkestone Beds.] Ann. Soc. Geol. Nord., t. iii. pp. 23-25. 

 Points out that both the Folkestone Beds and the Sandgate Beds are 

 represented at Wissant, and identifies the Ammonites mammillaris zone 

 of the former with the zone bearing the same name in the Paris Basin. 

 This the author regards as belonging to the Gault, and suggests that, as 

 there is a strongly marked line at the base of the English Eolkestone 

 Beds, the whole of them may be synchronous with the French Amm. 

 mammillaris zone, and should therefore be classed with the Gault. 



A. J. J-B. 



La denudation des Wealds et le Pas-de-Calais. [Denuda- 



tion of the Weald and the Straits of Dover.] Ann. Soc. Geol. 



Nord, t. iii. pp. 75-84. 

 Thinks that the existence of a plain of marine denudation is assumed, 

 not proved. It is likewise not proved that either the London Clay sea, 

 the Calcaire Grassier sea, or the Pliocene sea covered the district. By 

 studying the surrounding Cretaceous escarpments an explanation of the 

 denudation of the Weald not requiring any of these hypotheses is 

 arrived at. Concludes that the rivers there run in synclinals or in 

 anticlinals when these are broken. The folds of the Chalk have thus 

 determined the course of the W^ealden rivers, whether there was a plain 

 of marine denudation or not. The Straits of Dover are due primarily 

 to a set of fractures and folds which affected the Weald towards the 

 end of the Eocene period. G. A. L. 



