Blackheath, Lewisham, Charlton, Woolwich, and on the east of Plumsted. In all these places the thin bed next above the chalk, which at Reading contains fishes teeth and oysters, is seen composed of a similar substance of loose green sand mixed with chalk flints, both rolled and angular, and generally coated with a dark green crust; but here they contain no organic remains, and seldom exceed two feet in thickness. Above this thin bed is a thick stratum of fine grained ash coloured sand, destitute of shells or pebbles, and varying in thickness generally from 30 to 40 feet. This stratum is seen to the greatest advantage in the Woolwich sand pits, where is an enormous artificial section, presenting the following order of succession:[1]
Section of the Woolwich Pits, ascending from the lowest Strata.
| No. | Feet. | |
| 1. | Chalk with beds and nodules of black flint | — |
| 2. | Green sand of the Reading oyster bed, containing green coated chalk flints but no organic remains | 1 |
| 3. | Light ash coloured sand without shells or pebbles | 35 |
| 4. | Greenish sand with flint pebbles | 1 |
| 5. | Greenish sand without shells or pebbles | 8 |
| 6. | Iron-shot coarse sand, without shells or pebbles, and containing ochreous concretions disposed in concentric laminæ | 9 |
- ↑ Although a Section of these pits is already before the Society, it seemed necessary to insert that I am now giving, as it differs from Mr. Webster's (Geol. Trans. vol. 2, p. 195.) in a few minute particulars, and was the result of a careful examination by the Rev. Wm. Conybeare and myself, in April, 1815. I have also the sanction of Mr. Conybeare's authority, and am indebted to his observations, confirmed subsequently by my own, for the Notices, Map, and Sections, which I have given of the neighbourhood of Blackheath.
