| 11. | Dark red clay partially mottled and mixed with grey clay | 4 |
| 12. | Soft loam, composed in its upper region of line yellow micaceous sand, mixed with Hakes of a delicate ash coloured clay, which become more abundant in the deeper portions of the stratum, and having its lower regions much iron-shot, and occasionally charged with ochreous concretions, and decomposing nodules of iron pyrites. It is used to make soft bricks for arches | 11 |
| ── | ||
| Total | 57 | |
| 13. | Alluvium composed of clay, sand, and gravel, the gravel chiefly consisting of chalk flints, both rolled and angular, with a few pebbles of quartz, and of brown compact sandstone. This alluvium is covered by vegetable mould |
The oysters of No. 2 are remarkably perfect when first laid open, and seem to have undergone no process of mineralization; they soon fall to pieces by exposure to air and moisture. The chalk flints contained in it are many of them in the state of small rounded pebbles; in others the angles are unbroken. Both varieties are covered with a crust of greenish earth of the same nature with the green particles in the sand. The angular flints appear to have been derived from the partial destruction of the bed of chalk immediately subjacent, of which the upper surface in contact with the sand is considerably decomposed to the depth of about a foot, and its fissures and numerous small tubular cavities (the latter derived apparently from the decay of organic substances,) are filled with granular particles of the green earth and siliceous sand of the incumbent stratum.
