OPENINGS IN LIASSIC AND OOLITIC ROCKS OF OXFORDSHIEE 143 



10. Note on some recent Openings in the Liassic and Oolitic Rocks 

 of Pawler in Oxfordshire, and on the Arrangement of those 

 Rocks near Charlbury. By F. A. Bather, Esq., Scholar of 

 jSTew College, Oxford. Communicated by Prof. Prestwich, 

 M.A., F.R.S., F.G.S. (Read December 2, 1885.) 



[Abridged.] 



This account was written to bring before the notice of practical 

 geologists some new sections on the works of Messrs. Bolton and 

 Partners, at Fawler. The district treated of lies in quarter-sheet 

 45 S.W. of the Survey Map, and was described by Prof. Hull in his 

 accompanying memoir, 1859, to which nothing was added by Prof. 

 Green in his memoir, 1864. Accurate description rather than 

 speculation has been aimed at ; still, as some alteration seems neces- 

 sary, its probable lines are suggested from personal examination of 

 the neighbourhood. The Evenlode valley exposes Liassic rocks to 

 about I mile below Fawler, where Great Oolite is brought down by 

 a fault. Since the locality is well known, I proceed to describe the 

 sections in ascending order. 



Section A, in the brickyard (about the position of the " 2," in 

 " / " at Fawler). 



ft. in. 

 Soil formed by decomposition of marlstone rock -bed, containing in 



its lower part fragments of the same 1 



e. Eeddish-yellow loam, in alternating bands of more or less sandy or 



clayey nature ; a hard band at junction v^ith marlstone rock-bed 11 

 ?. Blue clay containing nodules of harder rock, and a few Septaria, 



visible for 20 



But a boring has proved the existence of the same rock to a further 



depthof 100 



The cores of the boring were not preseiwed ; they were, I am told, 

 of the same character throughout. The line of junction of beds e 

 and I, is 14 ft. above the bed of the river. 



Section B, in a coombe across the road N.E. of the brickyard, 

 clearly marked on the map by a branching-off of the Lias and In- 

 ferior Oolite into the Great Oolite plateau. A deserted opening 

 extends S.W. byN.E., along the north side of this coombe for nearly 

 200 yards. The strata here are so variable in thickness that no 

 definite section can be given. The lowest is marlstone rock-bed (o), 

 varying from 8 to 10 ft., but in one part so displaced that it appears 

 in vertical section 12 ft. thick. At the west end of the pit it has a 

 N.W. dip, circa 15°. Lying on the broken surface of this rock is a 

 blue clay (Upper Lias, y) with average thickness 5 ft. : this fills the 

 fissures of the marlstone, forming " clay joints," doubtless made 

 after upheaval by a sinking-in of the clay ; thus the surface of the 

 clay is itself rendered uneven. The clay is capped by a rubbly 

 limestone (/3), the zone of Clypeus Plotii, Inferior Oolite, here worn 



