Vol. 69.] 



BATIIOSIAN ROCKS OF THE OXFORD DISTRICT. 



491 







Thickness in feet inches. 

 ( Neseran Beds: these consist for the most part of 

 rapid alternations of greenish and blackish sands 

 and clays; the lithological character of the dif- 

 ferent beds varies considerably within a very 

 short distance ; only the following general section 

 can, therefore, be given about 18 



(a) Compact green clay, with much wood to 3 3 



(b) Green clay, yielding many specimens of 

 Cardium incertum Phil to 1 



(c) Laminated dark and light clay, locally 

 aim ost black ....*. 1 



(d) Grey and green sands, locally replaced by 

 a sandy limestone with rootlets 1 to 3 



(e) As t arte Limestone: a pale greyish- 

 green sandy limestone, crowded with 

 specimens of Astarte angulata Mor. & 

 Lye, and often containing rootlets 1 to 1 



(/) Dark-green claysyielding Cardium incertum 

 Phil., C. stric/dandi Mor. & Lye, and 

 Astarte a ngulata M.or. & Lye. , 1 



(g) Dark-green clays ; unfossilit'erous, except 

 at the extreme base, ivhere there is a 

 band of Ostrea sowerbyi Lye 



(h) Grey clays and sand, becoming darker at 



the base 3 



(i) Green clay 2 



Chipping-Norton Limestone Series, consist- 

 ing of: — 



(j) Grey calcareous sandy clay, yielding Pinna 

 cancellata Bean, Modiola imbricata Sow., 

 and Nautilus sp 2 6 



(7c) B i r d's-N e s t R o c k : a hard, sandy, argil- 

 laceous limestone with numerous black 

 specks, 1 which quickly weathers to a 

 sandy clay containing Hemicidaris bra- 

 venderi Wright, Rhynchonella sp., Pinna 

 cancellata Bean, Ostrea sowerbyi Lye, 

 Modiola imbricata Sow., and Zigzagiceras 

 wagneri (Oppel), 2 as also numerous 

 curious tube-like segregations of coarse 

 material, the possible origin of which 

 is discussed on a later page (see p. 503). 8 6 



f Bed I. False-bedded limestones, which pass laterally into a 

 pale lilac clay, when traced towards the tunnel 



J (? Chipping-Norton Limestone) 12tol5 



] Bed in. Black sand and clay 15 6 



I Bed n. Greyish-black sandstone 8 



l^Bedo. Compact dark sandstone 10 



Upper Lias sic Clay (at the tunnel-mouth). 







1 [Mr, L. Richardson has noted black specks in the Chipping-Norton Lime- 

 stone of Pointed-Heath Quarry near Chipping Norton ; see ' The Inferior- 

 Oolite & Contiguous Deposits of the Chipping-Norton District' Proc. Cottesw. 

 Nat. R Club, vol. xvii, pt. 2 (1911) p. 229.] 



2 Mr. S. S. Buckman considers that the specimen is probably an old-age 

 mutation. 



