90 



UPPER LIAS. 



Erocester Hill, near Stonehoiise, affords the best type of the zone of Ammonites 

 Jurensis. 



Section of Frocester Hill, near Stonehouse. 

 Fig. 30, 



" Upper Lias Sands." 

 Zone of Ammonites Jurensis. 



a, b, c. Inferior Oolite ; 70 feet. 

 D, E. Calcareo-ferriiginous sandstone (Cephalopoda bed) ; 6 feet. "] 



F. Yellow and brown sands, with inconstant and concretionary > 



bands of calcareous sandstone ; 150 feet ? J 



G. Upper Lias shale ; 80 feet = zone of Ammonites communis. 



H. Marlstone ; hard calcareous sandstone, resting on brown and gray sands, with bands and 



nodules of ferrnginous sandstone ; 150 feet = zone of Ammonites margaritatus. 



I. Middle Lias shale = zone of Ammonites capricornus. 



Inferior Oolite. 



Ft. 



A fine-grained oolitic limestone, similar to the freestones of Birdlip, Painswick, and 

 Leckbampton Hills; the upper beds exhibit a most remarkable example of oblique 

 bedding, the flaggy layers of which rest horizontally on inclined beds of freestone ; 

 thickness about .50 



A coarse, light, cream-coloured, gritty, cystalline Oolite, traversed at intervals by ex- 

 tremely crystalline shelly layers ; a great part of the rock appears to be composed of 

 fragments and plates of Crinoidece plates and spines of Echinidce, and comminuted 

 fragments of the shells Mollusca. This white rock has a most remarkable litholo- 

 gical character, and glistens brilliantly when lit up by the sun's rays. The shelly 

 and pisolitic seams which traverse this bed resemble those in the Pea-grit. The 

 surface of weathered slabs exposes numerous microscopic objects ; the rock, in fact, 

 is almost entirely composed of organic debris, and measures about 10 



A hard, fine-grained, oolitic, sandy limestone, of a light-brown colour, lithologically 

 difierent from b. It contains many fossil shells, which are extracted with difficulty, 

 and passes into a hard yellow Oolite with few fossils, attaining a thickness of 

 from 8 to 10 



[The lithological character of this rock is very different to that of d, on which it rests.] 



