THE CORALLIAN ROCKS OF ENGLAND. 303 



The chief interest in the Corallian beds here centres in those that 

 are seen in the Workhouse quarry, which are obviously on the same 

 horizon as in that at Highworth, and the variations of which are 

 exposed in the several quarries to the eastwards. The shell-bed of 

 this quarry we may fairly compare to the similar bed at High- 

 worth in the same stratigraphical position, especially as we notice 

 that this conchiferous feature is continued to the east. At Fa ring- 

 don, however, we notice a difference both above and below. Above, 

 we hero have the oolites immediately beneath the Rag ; there we 

 have sands and clays, which appear to be wanting here ; and these 

 two are the alternate types developed on different areas, as will be 

 seen by our future illustrative sections. Below, we have here a bed 

 with curious clay balls, representing, we may suppose, a kind of 

 pisolite ; and there we have a Coral-bed. Beneath these in all the 

 quarries is a kind of passage-bed to the Lower Calcareous Grit. 



In a quarry about a mile to the east of Faringdon we have a 

 section representing the arenaceous type of the upper beds, showing 

 how quickly we lose the excessively calcareous type. There are 

 here seen : — 



ft. in. 



1. Calcareo-arenaceous, partly false-bedded flags, with lenticular 



masses of calcareous sand, which produce the false-bedding, 

 containing Cidaris florigemma, Pecten fibrosus, and Lima 

 elUptica 4 ft. to 6 



2. Alternations of sands and clays in thin layers in the lower part, 



black from cai'bonaceous matter about 10 



3. Solid blue calcareous grit, with large flattened oolitic grains, 



rendering it almost, an oolite. Gcrvittia aviculoides, Pecten 

 lens, Littorina muricata (base of quarry). 



The whole mass hero looks so like calcareous grit that we re- 

 quire the guidance of the fossils to point out that the upper bed must 

 be closely underlying the Hag, and that the base bed corresponds 

 to the shelly beds of Faringdon. An additional feature of interest 

 here is the black carbonaceous band, similar to that which appears 

 in the Brewery section below the shell-bed, indicating probably the 

 proximity of land. 



Another section in the neighbourhood, a little further east, and 

 south of the high road, whence the stones are obtained to mend the 

 road, should be given as confirmatory of the above interpretation. 

 We have here : — 



1. Bed earth. ft. in. 



2. False-bedded fissile oolitic flags 1 ft. to 3 



3. Black and brown laminated sandy clays 3 in. to 1 



4. Shelly beds, with flattened nodules near the base 3 6 



5. Soft sands, becoming in places blue-hearted grit 5 



The succession of beds with the flaggy oolites at the top is here 

 too like that at Highworth to allow of much doubt ; and the fossils 

 of the shelly bed, Ammonites plicatilis, Cerithium muricatum, Pecten 

 lens, P. qucdiccsta, Gervillia aviculoides, Lima laviuscula, assist in the 

 correlation. The passage-bed below the shell-zone is not here well 



