the London and Hampshire Basins. 45 



and Hampshire^ and their probable connexion with the corre- 

 sponding lines of the vales of Pewsey, Warminster and Wardour. 

 The construction and arrangement of the chalk country will 

 follow ; and the whole will serve, when the drainage and other 

 geological and geographical features come to be considered, as a 

 suitable introduction to a reconsideration of the phsenomena of 

 disturbance and denudation. The district in question, moreover, 

 forms with the Boulonnais a convenient geological whole, whether 

 considered apart, or in conjunction with other " lines of eleva- 

 tion,^' or denuded countries of suspected contemporaneity. 



In reference to the connexion of the Weald with the Wiltshire 

 valleys above mentioned, the sum of our present knowledge may 

 be gathered from the following passage in Professor Phillips's 

 ^^ Treatise on Geology*/' *^^In England, two lines of subter- 

 ranean movement have long been known, by which the tertiary 

 and secondary strata have been raised into anticlinal ridges and 

 sunk into synclinal hollows. They both range east and west, or 

 nearly so ; one line, viz. from the Vale of Pewsey, by Kingsclere, 

 Parnham, Guildford, and through the Weald of Sussex to Bou- 

 logne, is somewhat parallel to the vale of the Thames, &c." And 

 in reference to the Vale of Wardour, and its probable connexion 

 with the western extremity of the W^eald, the latest information 

 is to be derived from Dr. Fitton's History of the Strata below 

 the Chalkf. Dr. Pitton says, '' The beds at Harnham Hill, im- 

 mediately on the south of Salisbury, are inclined to the north 

 (this should be dip to the north, the inclination southerly), and 

 about a mile to the west of that hill a curved ridge or horeshoe, 

 formed of the upper chalk, seems to be the first divarication of 

 the strata which bound the Vale of Wardour. It therefore 

 deserves inquiry, whether the continuation of the fissure pro- 

 duced by an upheaving on the east of this point may not be 

 discoverable in the space between Salisbury and the head of the 

 Wealden denudation." 



These two quotations will serve for the starting-points of our 

 inquiry ; and I will anticipate the result so far as to state, that, 

 as regards the Pewsey line of elevation, a vertical disruption is 

 traceable from Polkstone along the whole range of the North 

 Downs (and is mainly instrumental in prescribing their southern 

 limits), which, entering the chalk near Farnham, passes by, and 

 does not unite with the Pewsey anticlinal line, as continued on 

 in the Burghclere Hills and Vale of Kingsclere. And secondly, 

 in regard to the anticlinal line of Wardour ; that it is continued 

 across the Avon and the Test, and like the before-mentioned 

 northern line, passes by and dies out, but does not unite or inos- 



* Vol. i. p. 260 (Lardner's Cyclopaedia), 

 ru 0.1 e ^ Qgj,!^ Tvms., vol. iv. 2nd series, p. 245. '^-' ' 



