390 
THE CRETACEOUS ROCKS OF BRITAIN. 
In the north-western part of the county beds of the true Chalk 
Rock type are found, and made it easy to draw a line for the base 
of Upper Chalk round the Vale of Kingsclere and the other inliers 
above mentioned. 
The thickness of chalk between the Melbourn Rock and the 
Chalk Rock near Winchester, appears to be nearly 200 feet, and 
in all probability that is about its thickness along the main out¬ 
crop in the eastern part of the county. In the Yale of Kingsclere 
it does not seem to be more than 150 feet. Near Warminster, in 
Wiltshire, it is barely 100 feet thick. Thus the Middle Chalk 
appears to diminish somewhat rapidly westward. 
Stratigraphical Details. 
A. Sections along the Main Outcrop. 
Zone of Rhynchonella Cuvieri. 
Mi-. Hill found Rhynchonella Cuvieri and Inoceramus mytiloides 
in a small quarry two-thirds of a mile N.N.W. of Bury Court, near 
Bentley. There is also a quarry in hard massive chalk north of 
Lower Froyle, which may be in this zone. 
The Melbourn Rock and some of the overlying chalk, with Ino- 
ceramus mytiloides and other fossils, are well exposed in the railway¬ 
cutting south-east of Alton, and also in the quarry less than half 
a mile to the east just above the contour line of 400 feet. These 
exposures are in an outlier, and there is another smaller one on 
the hill east of Chawton House. 
The main outcrop passes west of Alton, Chawton, and Farring- 
don, and then spreads out over the high ground between Tis- 
ted and Newton Valence and thence eastward to Selborne Hill. It 
runs out again on to Noar Hill to the south of Selborne, where 
there are several large old quarries from which much chalk must 
have been taken in former years probably for burning to lime. 
South-west of Hawkley the outcrop of this zone becomes very 
narrow and is confined to the steep escarpment which terminated 
in the bold promontory of Wheatham Hill. Here the boundary 
lines drawn by Mr. Hawkins for the base and summit of the Middle 
Chalk are about 180 feet apart. 
West of Ramsdean the beds come within the influence of the 
Petersfield anticline ; the outcrop of the Melbourn Rock passes 
to the north of East Meon, and thence south-westward for some 
distance, returning along the southern border of the Meon valley 
to the hills above Buriton. 
The Terebratulina Zone. 
Mr. Hill identified the zone of Terebratulina in a quarry by 
Glade Farm, about a mile and a quarter north of Bentley. 
Professor Barrois (Recherches, p. 45) writes that the junction 
of Cenomanian and Turonian is seen to the north of Lower Froyle, 
and that the nodular chalk is overlain by a soft white chalk from 
which he obtained Calerites subrotund us. There are two quarrie^ 
