Reports & Proceedings — Geological Society of London. 179 



Morley Davies, A.R.C.S., D.Sc, F.G.S., and John Pringle, H.M. 

 Geological Survey. 



The two borings are about 370 yards apart in a due east-and-west 

 direction. The eastern boring gives the following section : — 

 Altitude of surface = about 290 O.D. Thickness in 



ft. in. 



4 



93 3 



Soil 



Oxford Clay — Ornatum zone . 



Non-sequence. 

 Forest Marble . . . . . . 38 9 



Non-sequence. 

 Great Oolite . . . . . . 59 6 



Non-sequence. 

 Chipping Norton Limestones . . .76 



Non-sequence. 

 Lias — Domerian, Algovianum zone to 



Charmouthian, Jamesoiii zone . 240 6 



Unconforaiity. 

 Lower Tremadoc — Shineton Shales . . 954 6 



1398 



The Oxford Clay is represented by grey and blue clays, the lowest 

 hed of which is a hard, tough, brownish clay full of broken shell- 

 fragments ; among the forms identified from it are Cosmoceras 

 sedgivicki (Pratt) and C. stutchburu? (Pratt). 



The Porest Marble consists mainly of grey and bluish-grey oolitic 

 and earthy limestones, with grey, brown, and green clays at the base. 

 An exceedingly bright bluish-green clay, 3 inches thick, is also 

 present. The limestones are very fossiliferous, but the organisms 

 are badly preserved. 



The Great Oolite is represented by grey limestones and grey marly 

 limestones, dark-grey sands, and clays. The highest member is 

 correlated with the ' Cream Cheese ' top of the Great Oolite in the 

 Bicester cuttings. From the upper part of the section Terelratula 

 hathonica, S. S. Buckman, was obtained ; near the base thfere is a 2 foot 

 band full of Rhynchonella and Ostrea. The section is compared with 

 the Fritwell-Ardley section on the new railway from Ashendon to 

 Aynho. 



The Chipping Norton Limestones consist of a yellowish oolitic 

 limestone and a grey sandy limestone, also markedly oolitic. 



The Lias is represented by pale-grey shales with very little 

 variation in character. JS^ear the base is a limestone containing 

 fragments of Palaeozoic rocks and many fossils, of which the most 

 abundant is Zeilleria waterhousei (Davidson), characteristic of the 

 Jamesoni zone. This limestone also yielded a derived fragment of 

 JEchioceras microdiscus (Quenstedt), a Raricostatum-zone fossil. 



In the western boring only, strata yielding inflammable gas were 

 met with. Reasons are given for believing that these may have been 

 Triassic. If not, they are probably Upper Palaeozoic. 



The Tremadocian shales resemble those of Shropshire ; their dip 

 varies from 40° to nearly 90°. They show interesting structures 

 resulting from differential movement; at several horizons they yield 

 well-preserved examples of Clo?ioffraptus tenellus, var. callavei 



