154 THE BATH OOLITE PERIOD. CHAP. 



The largest quarry now in work was opened some forty years 

 since,, and the excavation extends over an acre of ground or more. 

 The strata are thin, mostly alternating clays and shelly stone, to 

 a depth of twenty feet. Undulations on a large scale in some 

 groups of stony beds are terminated by a continuous plane surface 

 of softer yellow or white marly clay. False-bedding also occurs 

 under continuous plane shelly stone. The stone is blue in the 

 depths, but embrowned or tinted yellow by exposure at the surface 

 or along the joints. The surfaces are much and grandly rippled, 

 usually shelly, and especially covered with Ostrea, Pecten, Lima, 

 spines of Cidaris, fragments of Coral, Montlivaltia, Terebellaria, 

 and wood, all more or less drifted. The slates for roofing are of 

 small size ; some of the flags extend unbroken to six or eight feet 

 square. 



One of the best sections known is at the Kirtlington Station 

 on the Oxford and Birmingham Railway, which was thus recorded 

 by myself in 1859. 



CORNBRASH. 



Pale clays and interrupted thin laminae of 



Forest marble, oolitic and full of shells ft. in. 



and fragments ..... 120 



Solid shelly bed, top oolitic, middle close- 

 grained, base sandy .... 



Sandy and marly bed .... o 6 



Dark laminated clay with jet ... o 10 Cyrena. 



Pale blue clay with calcareous nodules . o 8 



Dark clay with jet . 08 



Pale blue clay o 8 



Brown clay o 9 



Sandy layer HZZ o 6 



Oolite, waterworn, with attached and 



drifted oysters and terebratulae . 24 



Parting clay :== = ==== = = ^ I ^ : ^ 



Oolite, usually compact .... 



Parting clay ======== 



Bed full of Terebratula maxillata, the 



valves united 3 



If this section be compared with those copied by Morris in the 

 Great Northern Railway cuttings of South Lincolnshire, the con- 

 formity of the groups will be evident. In both, clays of different 



