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



Wellington College Station. The depth of the pit is 9 feet, and all 

 round the sloping sides the pebble-bed comes out in a most unmis- 

 takable manner below a surface capping of Drift about 2 feet thick. 

 The pebble-bed itself is from 1 to 2 feet in thickness ; its altitude 

 is, within a few feet, that of the bed in Barkham Pit ; the pebbles 

 are embedded in sand, and not so compactly aggregated as they are 

 in the Barkham gravel-pit ; but there is no mistaking the character 

 of the bed. 



If we return to the Barkham Pit, and follow the 250 feet contour- 

 line eastwards and northwards, we can trace the outcrop by the 

 exposure of the pebbles at the surface. Where the hill-slope 

 is rather steep, they have been carried down the slope a few feet 

 by the wash of heavy rains and the action of melting winter- 

 snows. I traced a broad band of them across a turnip-field in 

 the spring of 1886, on a rather steep slope near Sandy Bottom. 

 Many of the pebbles were of large size (3 and 4: inches in length), 

 and so thickly strewn were they across the field that it was 

 impossible to step between them. As the contour-line is followed 

 northwards (on the east side of the Bagshot Outlier), we come 

 across the pebbles again in ditches and in the spinny to the north- 

 west of the Scotch Farm ; and they appear to crop out again at the 

 northern extremity of the outlier, outside the churchyard, which is 

 just on the 250 feet contour-line. 



There are not many sections of the sands above the pebble-bed, 

 but a small one occurs in the wood on the northern side of Birtle 

 Heath, where I made a clearance of the steep slope in several places 

 with a spade, and satisfied myself as to the Upper Bagshot character 

 of the sands. A more extensive section is exposed in the sand-pit, 

 to the east of Sandy Bottom, some 20 feet or so above the pebble-bed. 

 On one side of this pit there is a very fi-esh exposure of sands evenly 

 stratified ; but as these are followed round the pit, the stratification 

 disappears suddenly, as if it terminated against an ancient sand-dune. 

 The character of the higher bed in this pit bears a striking resem- 

 blance to one on the Wellington College Estate, in the Upper Bagshot, 

 not many feet below the 300 feet contour-line.-' Crossing over to 

 the west side of Sandy Bottom (in reality a small valley of erosion 

 with much sand-wash from the adjoining hills at the bottom), the 

 Upper Sands are again seen in the road-cutting, above the level of 

 the pebble-bed, and they can be seen along the same road as it skirts 

 the south side of Bearwood Park. On descending the hill into the 

 valley of the Loddon, we come again rather suddenly upon the 

 London Clay of the usual dull bluish-grey colour, as I saw it last 

 summer exposed in a fresh road-side excavation, with pebbles of 

 flint dispersed through it. Lithologically, I am unable to recognize 

 in the loamy bed which occurs in this outlier above the pebble-bed 

 anything but the equivalent of the loamj'^ (sometimes even clayey) 

 bed with which I am very familiar, as it occurs at about the same 

 altitude and above the pebble-bed, in the country about Wellington 

 College, and in other parts of the interior of the main mass of the 



^ I am not sure that they are not in reality, in both cases, parts of a later drift. 



