1 92 ARTESIAN WELLS IN DORSET AND ELSEWHERE. 



Thickness. Depth. 

 Ft. In. Ft. In. 



27. Hard grey sand with some clay, sets like a 



sandstone . . . . . . 130 275 o 



28. Green sandy clay and flints at bottom. An 



earthy green-sand ranging from pale 

 green to darker green ; the flints are 

 green-coated, mostly unworn and some- 

 what corroded . . . . 50 280 o 



Total Lower Tertiaries 1 1 ; o 



It is a decided gain to have obtained the exact particulars of 

 the Tertiaries, both as to character and thickness, in any one 

 spot in the county, and these the Bovington Borehole supplies. 

 Without doubt the Bagshot Beds are much thicker towards the 

 centre of the basin, at Worgret for instance, than they are here, 

 so near to their outcrop, nor can we say for certain whether this 

 difference is wholly due to removal of the upper beds by 

 denudation or to less deposition within the area. As might be 

 expected the Bagshots maintain their reputation as a sandy 

 series, but there is a certain amount of the usual clays, some 

 iron-stained, or blood-shot, and some approaching the character 

 of pipeclay. Nos. 10 and 12 may to a certain extent represent 

 the famous Pipe-clay horizon of the Creech district, and their 

 position in the series is not inconsistent with this supposition. 

 There is a marked change in the character of the sediments 

 below No. 15, which may fairly be taken as the base of the 

 Bagshots. In No. 16 we first encounter the black flint pebbles 

 so characteristic of a London clay horizon, but the Lower 

 Tertiaries throughout the county are so extremely uninteresting, 

 both from an economic and a geological point of view, that there 

 is no need to dwell upon details beyond pointing out that 

 No. 25 probably represents the plastic clays in the lower part of 

 the Reading Beds which are much used for brickmaking in 

 Dorset, 



