320 Geology of Wiltshire. 



of Seend may, one of these days, yield large profits, tut as yet the Freestone 

 bears the palm in a commercial point of view. 



The following account of the Great Oolite at Box, from the pen of Mr. 

 J. S. Eandell, is extracted from a paper read at the Meeting of the British 

 Association, Bath, 1864. Nowhere, I believe, in Great Britain (indeed in 

 Europe) are the lower members of the Jurassic group of rocks so extensively 

 developed as in the Bath district, where each group seems to have attained its 

 fullest recognized development. Nowhere can the whole Jurassic (Oolitic) series 

 be so readily studied — nowhere so readily understood. This applies to the Lias 

 in its three divisions ; to the Inferior Oolite, the Fuller's Earth, the Bath or 

 Great Oolite, distinguished here for its economical value, and at Minchin- 

 hampton and other places for its fine and typical organic remains ; and above 

 this series, but intimately associated with it, to the Forest Marble and Corn- 

 brash, which are highly developed, and succeeded by the Oxfordian and Kim- 

 meridgian groups, — not omitting the Portlandian beds at Swindon, and the 

 Purbecks of the vale of Wardour. I purpose to direct attention to the Bath 

 Oolite only, determining the position of that zone from which the freestone is 

 extracted, and on which the wealth and comfort of the population of this 

 neighbourhood, engaged in quarrying operations, so much depend. The natural 

 grouping of the beds constituting the Great Oolite in this district, falls under 

 three well marked divisions, all well exhibited in the sections exposed at 

 Murhill, Westwood and Farley Downs, Combe and Hampton Downs, Box and 

 Corsham Workings, &c., &c. Throughout the Bath area, immediately below 

 the Forest Marble (when present), we meet with the following groupings : — 

 1, The Upper Ragstones. 2, The fine Freestones or Building Bed. 3, The 

 Lower Ragstones. These constitute a series varying from 60 to 120 feet in 

 thickness. 



The Upper Magstones. — This series consists, in the upper part, of coarse 

 shelly limestones, with iisually a few beds of white fine-grained limestone, 

 possessing distinct and well defined oolitic structure, and containing finely 

 comminuted shells; these are again succeeded by tough argillaceous beds of 

 limestone, usually of a pale brown coloiir and smooth in texture. The whole 

 ranging from 25 to about 50 feet in thickness. No beds of workable vahie 

 occur in this upper series. 



The fine Freestone or Building Beds. — Succeeding the Upper Ragstones 

 above-mentioned, and commencing the second series, there appears to be every- 

 where in this district a peculiar bed, extending over a large area, tei'med the 

 "cover" or "capping," varying in thickness but generally hard in texture ; 

 this forms the roof or ceiling to the fine economical biiilding freestones below, 

 and is a marked feature in extensive underground workings, both for its hori- 

 zontal extent, and for its importance as a protection to the workmen. At 

 Bradford, Westwood, and Mui'hill, this bed is a coarse, shelly, hard limestone. 

 At Corsham and Box, it is a closer grained and tough rock. Succeeding this, 

 is the true " Bath Stone," or iine freestone, which I believe, with minor difier- 

 ences, occupy the same position or horizon over the whole of the Bath district. 

 It is fi'om 20 to 30 feet in thickness. The beds worked for commercial purposes, 

 are usually evenly grained in texture, regularly bedded, yield well to the saw, 

 are not fossiliferous (or the shelly matter is very finely comminuted), and give 



