102 Geology of the Railu-ay Line from 



as the West Woods, this being the westerly limit of the clay. 



From the iipper chalk also came the tliuts whence oiu' forefathers 

 obtained the Aveapons so well seen in Mr. Brooke's splendid collection 

 in Marlborough. 



Marlborough, thus favoured by its geology, was just the place 

 for an important j^rehistoric settlement, and of this we have many 

 evidences. 



Here the forest and the down met, there were flints for their 

 tools, and the river for their water-supply and for fish. Grame they 

 could find in the forest, and the down afforded pastm-e for their 

 flocks, and arable land as well. 



As I have gone at length into this matter in a paper published 

 in the Marlhorough College Natural History Society's Meport, 1890, 

 on " The Influence of Geology in forming the Settlement round 

 Marlborough," I can only thus briefly touch on it here. 



We must now proceed on our journey along the line, and go on 

 from Marlborough towards Savernake. 



After passing Hat Grate the strata which as far as Marlborough 

 have a steady southerly dip, thus bringing on higher beds in the 

 chalk, begin to dip very sharply the reverse way, to the north. 

 Mr. Codrington, in his paper, makes the dip as high as 45°. The 

 result of this is to reverse the outcrop of the strata, and the chalk- 

 rock, which we left at Ogbourne passing away under the upper chalk 

 to the south, is now brought up to the siu'face and well shown in 

 the deep cutting beyond Hat Grate, with the high north dip before 

 referred to. 



As this reverse north dip continues we still get lower and lower 

 beds in the chalk, and very soon reach the lower chalk with the 

 same hard gritty beds we had observed a little south of Chiseldon 

 (Station, and last of all Ave come once more on the upper greensand, 

 which disapi^eared at the northern end of Chiseldon cutting. 



Groing on past Savernake, along the Andover line, we cross the 

 northern end of the Pewsey Vale, and pass over the " anticlinal," 

 or uprise caused by some disturbance which has brought up to the 

 surface, strata that would never haA^e come up but for this. 



That we are passing over this arch or anticlinal is clear, for the 



