Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/188

94 Fig. 28 is a careful sketch of part of the Cyrena-bed, by Mr. S. Skertchly. The section is as follows, in ascending order:—sands 4 feet, wavy laminated brick-earth beds 6 feet, brick-earth 5 feet, a bed of pebbles from the Woolwich series, brick-earth, and clay 6 feet; the Cyrena sand-bed, C, passing upwards into laminated brick- earth, gravel, and loam, 25 feet thick.

Fig. 29 is a section of the most fossiliferous part of the Crayford pit.

Fig. 29.—Section in Crayford Pit.

along the line K L (see P1. VI.). It represents about 30 feet in height by 150 in length; so that the horizontal scale is about five times the vertical. It is intended to show the variation in the pebble-beds, C, and the thickening of the whole series in the direction of the escarpment. The pebble-beds, C, are in three divisions, and the great Cyrena-bed, D, rests on one of them; but shells are found in B, C, D, and E, though not in the covering bed F, which contains flint-pebbles distributed through it in the usual manner. The lowest beds are not seen in fig. 29; but at X, near M N, there are several openings at a depth of 35 feet from the surface, where a bed of coarse gravel is visible, which is near the eroded surface of the chalk. The chalk itself, with a covering of gravel or sand, is seen in the ponds marked P in the Crayford pit, where the Water stands a little below the level of high water.