46 



THE GEOLOGIST. 



capping the higher ground^ especially near Burford, Northleach, &c. 

 In some respects it differs lithologically from the same Formation on 

 Minchinhampton Common, and it is thicker in its extension eastwards. 

 The top strata usually consist of beds of marl, which are more or less 

 fossiliferous ; and the lower of white limestones, which are extensively 

 quarried near Sherborne Park, above Burford : and, according to Mr. 

 Hull, these limestones contain more fossils at a quarry where the 

 Oxford and Shilton roads join, than anywhere else. Near Andoversford, 

 about seven or eight miles east of Cheltenham, many fossils may also 

 be procured in beds of rubbly, white Oolite. The usual fossils are 

 shells and corals, belonging, however, to comparatively few genera, 

 and presenting in this respect a strong contrast to the Great Oolite on 

 the south. 



The Forest Marble appears at Coin E,ogers and near Aids worth, 

 about six miles south-east of "N"orthleach, as well as near Burford, and 

 the Cornbrash also near Shilton. We merely, however, mention this 

 in case the student should like to compare them with their equivalents 

 near Cirencester ; for it often happens that even within a very few miles 

 the divisions and sub- divisions of any given Formation present striking 

 lithological differences — certain beds coming in, and others thinning 

 out, which it is always necessary to note carefully, and which can only 

 be done by a minute and accurate examination of every available section, 

 and a close comparison of the zoological contents of each stratum.^' 



There is another and very important member of the Great Oolite with 

 which it is intimately connected, and of which it forms an integral 

 part, viz., the Stonesfield slate, to which we must now turn our 

 attention. It forms the lower division of this Formation, and consists 

 of a coarse, brown, fissile, ragstone, sometimes sandy and slaty, or 

 passing into a shelly, oolitic freestone ; and these characters are very 

 variable over a considerable area in the Coiswolds. Formerly, there 

 were several quarries worked at Sevenhampton Common, five miles east 

 of Cheltenham, and are even now well worth a visit. The ragstone, 

 which is a more compact slaty stone, often blue in the centre, is there 



* We advice the student to get Mr. Hull's valuable and interesting memoir on 

 " The Geology of the Country round Cheltenham," published by the Geological 

 Survey, price 2s. 6d., where detailed sections are given, Avith copious lists of fossils, 

 and ample details of every spot worth visiting. 



