302 J. F. BLAKE AND W. n. HTJDLE8ION ON 



a. The top block is a hard calcitic limestone, with ft. in. 



Theoosmilia in the upper part. The central and 

 lower portions are seinicrystalline pisolite. The 

 fossils are small ; and we may consider the bed to 

 belong to the group of coral shell-beds, which 

 sometimes underlie the Eag G 



b. Oolite of variable hardness, and rather shelly towards 



the middle, with hard crystalline nodules, and an 

 Urchin-bed of Pygastcr wrcbrella and Echinobrissus 

 scutatus, &c 2 



c. The principal shell-bed. A fawn-coloured lime- 



stone, gritty, and only moderately oolitic, with 

 abundance of large shells — Trigonia Meriani, T. 

 per lata, Hi/mites velatus, Astarte ovata, Pecten 

 fibrosus, P. lens 1 1 



d. A dirty-yellowish limestone, partially oolitic, with 



curious flattened lumps of marl of smooth sur- 

 face 8 



The building-stones (3) are coarse, ironstained, sandy oolites, blue- 

 hearted towards the base. They contain much wood, and some large 

 fossils, including Pecten lens, Perna mytiloides, and Gervillia avicu- 

 loides. Below this are loose sandy beds, becoming sufficiently argil- 

 laceous to hold up the water. The continuation downwards cannot 

 be anywhere satisfactorily traced on the surface, the section in the 

 Lechdale road, alluded to in the Survey memoir, being no longer 

 visible ; but the following well-section exhibits completely the litho- 

 logy of the lower beds, which, if all are to be reckoned as belonging 

 to the Lower Calcareous Grit, have here an enormous development : — 



Section of Bore-well at Fairtliorne and Phillips's Brewery, Faringdon. 



Coralline oolite (the same as in the lower part of the ft. in. 



Workhouse quarry) 6 (3 



Sandy clay, with much carbon, and curious white 

 nodules (?). The lower portion of this bed holds 

 up the water in the Workhouse quarry, and at the 



bridge over the railway 4 



Coralline (?) and shelly limestone, hard and subcrys- 



talline, with loose marly stuff at base 10 6 



Water of shallow wells. 



Grey sandy clay 9 6 



Similar, but less coherent 9 



Similar 11 6 



Line of subcalcareous nodules 2 6 



Dense grey clay 2 



Grey sandy clay 8 



Impure grey oolite, and hard grey calcareous grit ... 6 



Water. 

 Loose grey quartz sand, extremely fine in grain, with 



a few plates of mica 5 



Grey sandy clay 13 



Grey clayey sand 5 



Water, 53° R, constant. 



Grey clayey sand 4 



Grey sand, rather more argillaceous 5 



Grey argillaceous indurated grit, of fine grain 13 



114 G 



