Chiseldon to Collingbonrne. 



95 



shore, and the shore-line of the upper greensand was to the north 

 and west, and at the close of the period, when the Warminster heds 

 were being deposited, the whole of south-eastern and central England 



1 was covered by a sea, nowhere more than one hundred or one 

 hundred and fifty fathoms deep, and gradually shallowing westward. 



" To the south-west it stretched to the borders of Dartmoor, and 

 washed the foot of the Quantock Hills ; the valley of the Bristol 



~ Channel was a deep inlet, and thence the shore-line swept north- 



. ward below the hills of Glamorgan, Monmouth, and Hereford. 



" The sea then trended north-east to Derbyshire, and passed up the 



"eastern side of the Pennine range. 



I am here following Jukes-Browne and his book, the " Building. 

 <§f the British Isles." 



This sand is greenish grey in colour, consolidating into a sand- 



" stone at times ; pale calcareous sandstones and chert also occur. 



I These calcareous sandstones are sometimes called flrestone, and are' 



II well developed at B^eigate. The' green colour is due to glauconite,. 

 a hydrous silicate of iron, alumina, and potash. 



" The upper greensand was laid down near a coast-line, and 

 '^indicates a physical change and a diversion from the mud-bearing 



currents of the ganlt sea. 

 rt As the outcrop of the upper greensand is not very wide, the bed 

 " not being very thick and the dip a good one, the space it occupies 



0 on the surface of the ground is a narrow one. 



This is bed number 3 in the diagram, where it is seen rising up 1 

 under the chalk in the cutting and then spreading out on the map 

 by Badbmy, Licldington, and "Wanborough. 



1 But narrow as the outcrop is, it has a marked effect on the 

 scenery, as may be seen in the narrow and picturesque gorges cut 



• through it at Chiseldon and Wroughton, to mention only two 

 instances out of many. All along the escarpment of the chalk, 

 : ' villages are found to be situated on the outcrop of the upper green- 



^ sand. 



i 



ii Effects of Escarpments on the Shape of Parishes. 



The variety of soil, too, found to exist in passing from the top of 



k 



