the London and Hampshire Basins. 49 



sected by the Southampton Railway at the height of 454 feet above 



the sea-level ; but at this point it has lost much of its intensity. 



Westward from Popham I cannot say that I have made a very 



satisfactory exploration. Denudations and river-courses, and 



the absence of satisfactory sections just where they are wanted, 



make it very puzzling. My impression is, that, keeping the 



infant Test in its northern synclinal line, it passes the great gap 



in the Burghclere Hills north of Whitchurch, and takes on in 



the vicinity of Andover towards Waybill. The stratification of 



the chalk-pit on the south side of the town of Andover exhibits 



too much dip to have come from the Burghclere line without a 



reduplication; and the occurrence of a considerable tract of 



country of a tertiary character in Harewood Forest, favours the 



supposition of a synclinal arrangement. However this may be, 



the superior swell of the Pewsey line of upheaval now throws all 



other into shade, and the drainage is sufficient evidence of the 



constant slope southward of all the country west of the Popham 



heights, and the almost entire extinction of this line of elevation. 



au ■ i 



^^. ■ 



At this stage of the inquiry, finding that there was now no 

 chance of the Peasemarsh running into the Pewsey anticlinal, 

 and that I was moving in a line parallel with the Burghclere 

 Hills, eight miles north of Popham, it became a point of much 

 interest to ascertain the progress of the Pewsey line, and how it 

 stood in relation to the one I have been describing. 



As all the relations of the Vale of Pewsey are well known, and 

 the history of its anticlinal line has been carried on by Dr. Buck- 

 land* through the vales of Ham and Kingsclere, it would be 

 superfluous to repeat them. The great peculiarity in the fea- 

 tures of this line, after leaving the Pewsey denudation, is its ex- 

 treme irregularity. 



In the Vale of Pewsey the axis of elevation appears to run 

 nearly in the centre of the denudation, the strata sloping off 

 with a gentle declination north and south. But in its progress 

 eastward the northerly dip is much sharper than the southerly f. 

 The effect of this disposition is to bring the tertiary beds often 

 almost to the foot of the Burghclere Hills. This is particularly 

 perceptible after the line emerges from the Vale of Kingsclere. 

 At the eastern extremity of this valley the chalk is confluent at 

 Wolverton Farm. East of this confluence a well-marked anti- 

 clinal chalk valley runs out towards Monk-Sherbourne ; and evi- 

 dence may be obtained of the northerly dip, in Wolverton chalk- 



* Geol. Trans., vol. xi. 2nd series, 

 t Dr. Buckland, loc. cit. 



Phil, Mag, S. 4. Vol. 2, No. 8. July 1851. E 



