

By Prof. C. LLOYD MORGAN, T.G.S. 



1. General Features of the District. 



THE branch line of railway to Thornbury breaks off 

 from the Midland line to Gloucester, at Yate Station. 

 It then takes a curved course over strata belonging to the 

 Coal-measure series, with occasional exposures of Pennant 

 Sandstone by the rail-side, through Iron Acton to Range- 

 worthy ; after which it runs N.W. across a Triassic flat to 

 Tytherington. Alighting at Tytherington Station, we see 

 before us the Mountain Limestone which forms part of the 

 northern rim of the Bristol coal-field, and along which runs 

 the northern water-shed of the Avon basin. The higher 

 ground of the Limestone is broken into by a deep inlet 

 occupied by Triassic beds, on which the little village of 

 Tytherington is for the most part built. The valley which 

 thus runs up into the Limestone separates Tytherington 

 Hill on the east from a hill to the west on which runs the 

 oval rampart of a British camp known as the Castle. As 

 is usual in such cases, the rampart is best marked to the 

 north, where the natural defence of the steep hill-side is 

 absent West of the Castle Hill, between it and Woodleaze 



B 



