94 PROCEEDINGS OP THE GEOLOGICAL SOCIETY. [DeC. 21, 



Chalk, with flints in the top part ; at the bottom a thin fissile greenish layer 



(which also occurs on the coast eastwards). 

 Chalk-rock ; a layer of hard green nodules, the upper surface better marked 



than the lower. 

 Chalk without flints. 



In a larger pit, at the kiln above Kollington, on the northern side 

 of the range, and therefore in the higher part of the Chalk, there 

 are but few flints. 



The step -like outline of the top of the hills from Corfe Castle to 

 Nine-Barrow Down has been noticed elsewhere *. Westward of the 

 former place the range again rises by steps in a like manner, and is 

 partly breached at the western end of Knowl Hill. Here there is a 

 pit in Chalk with few flints, at the northern foot of the hiU, whilst 

 further south, and therefore lower down stratigraphically, another 

 pit shoAVS Chalk with layei's of flints, and with a sort of shckenside- 

 surfaces at right angles to the bedding. StUl further south, the road- 

 cutting up the slope southwards is in Chalk with flints ; but at the 

 top of the rather low hill the flints seem to end, and as the road turns 

 down again eastward the hard cream-coloured nodular Chalk-rock is 

 shown, and below it Chalk without flints. 



From this slight gap in the escarpment a longitudinal combe runs 

 westward as far as Screech Barrow, making two ridges. Screech' 

 Barrow itself is a conical Tertiary hill, close to and rising above the 

 chalk-escarpment. 



Signs of the Chalk-rock were again seen on the newly cut road 

 above "West Tyneham. 



There are many small pits on the flank of the escarpment in the 

 so-called Isle of Purbeck, showing Chalk Marl and Lower Chalk, 

 but not high enough to touch the ChaUc-rock. The Chalk is through- 

 out rather hard. 



Flower's Barrow, on the top of the ridge where it again meets the 

 sea, is one of those instructive gauges of the loss of land by the sea 

 that are often given us by the old earthworks. Nearly half of the 

 entrenchment has been carried away, and the high cliif now cuts 

 through its middle part. Here the top part of the Upper Greensand 

 stands out, from its hardness. I could not see the Chalk-rock along 

 the top of the cliff, nor could I get near enough to the foot in a 

 boat ; but a bluish-grey clayey bed, some feet thick, could be made 

 out at the top part of the Chalk Marl, as in the eastern coast-section. 



At the headland on the western side of Worbarrow Bay there is a 

 natural arch at the foot of the cliff, through which small boats 

 can go. 



In Mewps Bay the following succession of beds may be seen along 

 the shore : — 



•TT f Chalk with flints, running out to sea as a ledge, with a hollow and 



Ch Ik 1 ^^^® ^^^ ^° ^^® ^^^^" 



■ [ Chalk without flints (?), about 15 feet. 



* ' On Subaerial Denudation and on Cliffs and Escarpments in the Chalk and 

 the Lower Tertiary Beds.' Reprinted, with corrections &c., from the Geol. 

 Mag. vol. iv. 



