Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/186

92 for a long time. The chalk is excavated at the tramway to 20 feet above the Ordnance datum-line, and, is 55 feet high at E, where the Thanet sands (B) are nearly in situ.

The curve in the line of section gives an appearance of flexure to the veins of flints in figs. 24 and 25 which does not really exist. These bands are not far from horizontal.

Fig. 25.—Section in Crayford Pit.

Fig. 25 is along the line T U, Plate VI, and shows the eroded surface of the chalk in an oblique direction to the old river-channel. The gravel (B) is very conspicuous, and the brick-earth series (D) is thinner than usual; but this is due to the distance of U from the escarpment. To the east of U the brick-earths gradually thin out, and the upper and lower gravels unite, forming a bed of coarse gravel 8 or 10 feet thick lying on the chalk. The height of the point T is about 40 feet, and the chalk under U about 20 feet, above the Ordnance datum-line.

Fig. 26, a section along the line I J, offered good opportunities

Fig. 26.—Section in Crayford Pit.