Rev. A. Irving — Outlier of Upper Bagshot Sands. 113 



exposed in the pit pass northward under the hill-slope, which is 

 occupied by a ploughed field. On the southern side of the quarry a 

 bed beneath the pebble-bed is exposed ; and the lithological resem- 

 blance between this and the bed exposed beneath the pebble-bed ^ in 

 the railway-cutting at Wellington College Station is very striking. 

 I subjoin a diagram of the section as it is exposed in the gravel-pit, 

 of which a description has just been given. The full thickness of 

 the pebble-bed and the nature of the subjacent bed on the north side 

 were proved by an excavation which Mr. Walter was good enough 

 to have made for me. 



I am aware that several very competent geologists, whose oppor- 

 tunities for detailed observation of the stratigraphy of the Bagshot 

 Series have been but limited, are very sceptical as to the existence of 

 veritable Bagshot pebble-beds, since in many instances, these beds 

 have been examined at the present surface, where, in arresting 

 further denudation, they have often got somewhat reconstructed and 

 mixed up with a few discoloured subangular fragments of flint 

 (which belong to the later Quaternary Drift, and are easily recogniz- 

 able) ; but I am quite sure that such scepticism would be removed by 

 an inspection of this Barkham pit. The pit was re-opened only last 

 winter', after having been disused for years, and getting quite over- 

 grown with weeds and brambles. The pebble-bed crops out in great 

 force in the gardens of the ailjoining cottages, and in the lane which 

 runs along the south side of them. 



The bed of pebbles exposed in the gi-avel-pit just described runs 

 through beneath the road which leads up the west side of the field 

 in which it is situated towards the southern boundary of Bearwood 

 Park, and is seen again in the wood which covers the slope of 

 Coomb Hill behind Barkham Vicarage, where it forms a rude 

 terrace, numerous flint pebbles appearing in the sides of the ditch, 

 and even here and there among the forest-litter. In this direction 

 it has been proved recently by a trial shaft sunk in the nose of the 

 hill at a spot about 260 feet above O.D. In this hole some 6 feet 

 of buff-yellow loamy sand is at present exposed in a fresh section, 

 which no unprejudiced observer who knows the stratigraphy of the 

 Bagshots of this district could, I think, hesitate to refer to the Upper 

 Bagshot. On following the 250 foot contour-line through the wood, 

 the frequency of the occurrence of pebbles shows the extension of 

 the deposit in that direction. There is no exposure that I have been 

 able to find in Bearwood Park, as the same contour-line is followed 

 towards Bearwood Lake ; and as the line is followed towards the 

 house, everything is covered up with ornamental shrubberies and 

 gardens. The model gravel-walks through these are, however, little 

 else than artificially reconstructed "pebble-beds." 



At rather less than half a mile to the south-east of the house, an 

 excavation for a reservoir was made a few years ago. I saw it when 

 just dug, in company with my former pupil, Mr. Norman Walter, 

 and was fairly puzzled at the time, from the extraordinary resem- 

 blance of the sands exposed to those in our railway-cutting at 

 1 Bed No. 4 of my section, Q.J.G.S. April, 1885. 



DECADE III. VOL. IV. NO. HI. 8 



