OF THE INFEEIOR OOLITE OF GL0IJCESTBR3HTRE. 



269 



Yig. 2. — General Section of the Lower Beds of the Inferior Oolite in 

 the Stroud Area of the Cottes^volds. Scale Y^y-in. = 1 ft. 



Freestone 





Pea Grit, 3 ft 



''■•'-*-i\V{':'''.'v- 





( 1 

 1 1 





^ 



Lower 



Limestone, 25 ft. 



^M 





.'i rr, _ \ 





i. . [ 





•^ J 





^ ! I 





A i ' 



Ditto, Sandy, 9 ft. 





haJopoda-bed, o ft. 













Brachiopoda, Conchifera, 

 Echiaodermata, abundant. 



Gasteropoda, rare ; detritus of 

 encrinites, shells, &c,, in 

 layers. 



Conchifera in the lower bed 

 locally abundant. 



Cephalopoda, Brachiopoda, 

 Conchifera, abundant. * 



As the result of my observation I give the following summary of 

 these basement-beds (fig. 2) : — 



1. Pea Grit, including the pisolitic beds, well developed in the 

 Cheltenham area and at Birdlip, becoming thinner at Painswick 

 Hill, and having a thickness of 3 to 5 feet in the Stroud area, 

 extending to TJley Bury, where it appears as a thin band having 

 nearly lost its ferruginous aspect. 



2. Several beds of white oolitic limestone having layers of free- 

 stone alternating with layers of detritus of Crinoidea, Echinida, 

 and shells, and containing locally small quartz pebbles ; in 

 places highly crystalline and containing, in the Stroud area, a 

 bed of considerable thickness — 20 to 30 feet. 



3. Brown sandy limestones in several beds, locally coarse ferru- 

 ginous gritty beds, very fossiliferous in the lower portion, lying 

 on the Cephalopoda-bed — 5 to 9 feet. 



4. Cephalopoda-bed. 



These beds show, on close inspection, that the oolitic structure does 

 not commence with large pisolites as hitherto supposed. In the 

 sandy limestones (3) the oolitic structure is almost absent, but in the 

 overlying white limestone (2) it becomes more apparent, and the 

 upper beds are still more oolitic and more nearly resemble the free- 

 stone. The large grains of the Pea Grit come in suddenly and 



