252 N 'otic es of Books. [April, 



sheet, should be accompanied by short explanatory memoirs. 

 But, since it necessarily happens that the areas comprised 

 within these sheets are bounded in an arbitrary fashion, it be- 

 comes in the highest degree desirable that — as the work of the 

 Survey progresses, and districts with well-defined natural limits 

 are worked out — the information scattered through the shorter 

 memoirs on the separate sheets should from time to time be 

 gathered together and expanded into special volumes, each 

 devoted to a full description of the geology of some extensive 

 tract of country, bounded by well-marked physical features. 

 Such a volume is the admirable memoir by Mr. Whitaker on 

 the Geology of the London Basin. 



Much misconception prevails respecting the true nature of 

 this so-called " Basin." Misled by the popular use of the term, 

 and accustomed to the caricatured sections given in most geo- 

 logical works, one finds it difficult to realise the very gentle 

 nature of the trough in which the metropolis is seated, and the 

 true dip and relation of the beds within the London area. But 

 on studying the sections issued by the Geological Survey, which 

 are drawn on the same scale horizontally and vertically, it is 

 immediately seen that the disturbances which have affected the 

 strata in the south of England have been of the tamest possible 

 kind — that there have been no vast foldings of the beds, no 

 great elevation here or depression there — and*' that such high- 

 sounding phrases as "the great arch of the Weald," or "the 

 deep trough of the London Basin," are equally deceptive. 

 " When compared with its horizontal extent," says Mr. 

 Whitaker, " the vertical displacement in the latter area is indeed 

 trifling." 



The chalk is the lowest formation exposed within the London 

 Basin, though well-sections have reached the Upper Greensand, 

 the Gault, and certain lower beds — perhaps of Neocomian age, 

 or even older. Above the chalk come the Lower Eocenes, com- 

 prising the Thanet beds, the Woolwich and Reading beds, the 

 Oldhaven beds, and the London Clay. It may not be amiss to 

 remark the name " Oldhaven beds " was proposed by Mr. 

 Whitaker, in 1866, for some sands and pebble-beds equally dis- 

 tinct from the London clay above and from the W'oolwich beds 

 below. These beds are well exposed at Oldhaven Gap, on the 

 Kentish coast, near the Reculvers. Passing from the Lower to 

 the Middle Eocenes, we find in the London Basin the Lower, 

 Middle, and Upper Bagshot series ; but the beds above these 

 are not represented in the London area, and to study the 

 Eocenes it is necessary to cross to the Hampshire basin. As to 

 the various superficial deposits, they are well enough exposed, it 

 is true, within the London basin, but it formed no part of Mr. 

 Whitaker's plan to describe them, as it is proposed that they 

 shall form the subject of the second part of this volume. 



In the systematic preparation of this memoir, Mr. Whitaker's 



