•UPPER EOCENE (BARTON AND UPPER BAGSHOT FORMATIONS). 615 



The reasons for believing this sand to be Upper Bagshot and not 

 Lower Bagshot, as mapped, are as follows : — 



The chalk is about | mile to the north, and there is a high dip to 

 north. Along the railway north of the Highclere Station the 

 following beds are exposed : — 



1. Yellow sand, close to the Station. 1 .-n 1 1 i \ 

 o ri • I, 1 J t (Bracklesham.) 



z. (jreenisn, very clayey sand. J ^ '^ 



3. Yellow sand, rather clayey, a considerable thickness. (Lower 



Bagshot.) 



4. Judging from wet fields below the level of the line, there 

 appears to be a considerable thickness of clay here. (London Clay.) 



5. Yellow and mottled clay. 



6. Yellow sand. J. (Beading Beds.) 



7. Green-coated flints and Ostrea, 



8. Chalk with high dip to north. 



The sands in the pit in question resemble the Upper Bagshot of 

 the chief mass, and they differ from the ordinary Lower Bagshot in 

 the following particulars : — 



1. Absence of clay laminae. 



2. Presence of green grains. 



3. Absence of current-bedding. 



4. Presence of casts of shells in sandy concretions resembling those 



found in known Upper Bagshot. 



We think we have now said enough to show the character of the 

 Upper Bagshot beds, and the persistence of the pebble-bed at their 

 base. As previously stated, they lie in a slight syncline of the 

 Bracklesham, and are probably conformable to them. At Csesar's 

 Camp, Easthampstead (5), the base of the Upper Bagshot is above 

 the 300-feet contour; at Wellington College (41) it is 264 feet 

 above ordnance datum, at the Albert Asylum (14) about 165 feet, 

 at Tunnel HiU (21) rather under 237 feet, and at Ash (22) it has 

 again risen above the 300-feet contour. 



The Upper Bagshot beds are thus distinguished by the elevation 

 they attain and their barren aspect, the chief and almost only 

 vegetation they support being scanty heather, whortleberry, stunted 

 gorse, and Scotch pine ; while the lower-lying Middle Bagshots are 

 of a more swampy nature, and support deciduous trees and shrubs. 

 The presence of the dividing pebble-bed can almost always be 

 detected, however overgrown, if carefully searched for. Though 

 now consisting solely of whitish-yellow sands, a little loamy towards 

 the base, faint bands of colour denote the former bedding, while 

 occasional irony concretions, piping, and small blotches testify to 

 the extreme changes induced in their composition by percolating 

 water. Bichly fossiliferous and varied as we know the Upper 

 Bartons to be in Hampshire, when covered and protected by im- 

 pervious beds of clay, we have seen them assume the same 

 monotonous and unfossiliferous condition the moment the outcrop 



