Dana and Chambers on Ancient Sea-Margins, 207 



Mr Chambers introduces the subject with the following 

 statements : — 



" The most familiar phenomenon connected with this subject is the 

 existence of stripes, as well as broad expanses of low land bordering on 

 the sea, in many districts of a yery equable surface, sometimes of sandy, 

 sometimes of clayey composition, occasionally presenting beds of shells ; 

 comprehending, in short, the great bulk of those flat tracts which have 

 been — usually on account of the latter feature — recognised as ancient 

 beaches, comprehending also the well-known carses of Scotland, as well 

 those still lower sandy tracts near the sea, called in our country linkSf 

 and in England downs. The class of lands so described may be said to 

 form an irregular fragmentary belting round the island, strikingly dis- 

 tinct from the higher grounds which rise inland, generally of great agri- 

 cultural value, and remarkable as forming the sites of many of the prin- 

 cipal towns of the empire, or of large portions of them. As they almost 

 everywhere tell a plain tale as to their former submergence by the sea, 

 the idea may the more naturally occur that, were they by any accident 

 re-immersed, a very important deduction would be made from the geo- 

 graphical area, and still more from the productive resources of our 

 island. 



"As striking examples of this class of lands, I may point to the sea- 

 side plain, stretching for several miles on both sides of Chichester ; to 

 the similar plain extending along the south shore of the Bristol Channel, 



word drift, as it is often used. It is frequently applied to any loose material on 

 the surface, not originating where found, whether stratified or unstratified. This 

 name being affixed to any accumulations, one or another drift theory comes in to 

 account for the facts — such as the currents and icebergs of an ocean over the 

 submerged lands, the action of waves of translation, or the movement of gla- 

 ciers. The term in its very nature implies a theory of this general character. 

 But there is much material of the kind called drift, which may be of sea-shore 

 or beach accumulation ; there is much also which may be of river origin, and 

 much that may be lacustrine. Instead of determining by observation the actual 

 facts in the different cases, and carefully discriminating, the mind is led away 

 by the term drift at once to prejudge, to the confusion and error of observations. 

 In its general signification, it had better therefore be rejected; such truthful 

 terms as earth, sand, gravel, clay, boulder accumulations, are preferable, until it 

 is fully determined that the material in any case is true drift, and not alluvial, 

 lacustrine, or of beach or sea-shore origin. First prove it to be drift (often a 

 difficult problem), and then so designate it, is a safe rule. 



We have been led into these remark, by observing, not unfrequently, that 

 river terraces and beach deposits were ranked with the drift ; and when once 

 so called, every succeeding step in investigation leads into deeper error. 



