167 



THE 



deolojjg of tlje §cti.s & pants extension, 



By Thomas Codrington, Esq., F.G-.S. 



HAYE been asked to throw into the form of a paper for the 

 Wiltshire Magazine, such notes and observations on the 

 Geology of the country passed through by the Berks and Hants 

 extension, and the Marlborough Railways, as were accumulated 

 during the construction of those works ; and which unless recorded 

 in such a way, would soon be forgotten, or lost sight of. 

 Perhaps the most convenient plan will be — 



I. To describe the points of interest on the Berks and Hants 

 Extension Railway as they are met with in going from Hunger- 

 ford to Devizes. 



II. To traverse the Marlborough Railway in a similar manner 

 from Savernake to Marlborough, and 



III. To enter into some general observations and conclusions 

 with regard to the vale of Pewsey. 



I. The Berks and Hants Extension Railway. 



At Hungerford, the excavations for the roads exposed a clayey 

 flint gravel resting on the chalk. It is doubtless a high level 

 gravel of the Kennet, but no remains of any sort were found. In 

 the low grounds peat and gravel were touched upon, and a few 

 bones of horse and deer occurred below the peat. 



In the deep cutting soon reached, the upper chalk is covered 

 only by a few inches of soil. The chalk is stained brown in 

 waves and folds for a depth of 3 or 4 feet from the surface ; not a 

 rare occurrence in chalk covered b}^ only a thin soil, but not easily 

 accounted for. Soon after passing through the cutting a tributary 

 of the Kennet is crossed. Here about 100 yards to the south of the 

 Railway under a clump of trees is the outlet of a " swallet," or 



