Section of concentric beds west of Cromer.
- 1. Blue clay.
- 2. White sand.
- 3. Yellow Sand.
- 4. Striped loam and clay.
- 5. Laminated blue clay.
At some points there is an apparent folding of the beds round a central nucleus, as at a, [fig. 115.], where the strata seem bent round a small mass of chalk; or, as in [fig. 116.], where the blue clay, No. 1., is in the centre; and where the other strata, 2, 3, 4, 5, are coiled round it; the entire mass being 20 feet in perpendicular height. This appearance of concentric arrangement around a nucleus is, nevertheless, delusive, being produced by the intersection of beds bent into a convex shape; and that which seems the nucleus being, in fact, the innermost bed of the series, which has become partially visible by the removal of the protuberant portions of the outer layers.
To the north of Cromer are other fine illustrations of contorted drift reposing on a floor of chalk horizontally stratified and having a level surface. These phenomena, in themselves sufficiently difficult of explanation, are rendered still more anomalous by the occasional inclosure in the drift of huge fragments of chalk many yards in diameter. One striking instance occurs west of Sherringham, where an enormous pinnacle of chalk, between 70 and 80 feet in height, is flanked on both sides by vertical layers of loam, clay, and gravel. ([Fig. 117.])
Fig. 117.
Included pinnacle of chalk at Old Hythe point, west of Sherringham.
- d. Chalk with regular layers of chalk flints.
- c. Layer called "the pan," of loose chalk, flints, and marine shells of recent species, cemented by oxide of iron.
This chalky fragment is only one of many detached masses which have been included in the drift, and forced along with it into their present position. The level surface of the chalk in situ (d) may be traced for miles along the coast, where it has escaped the violent movements to which the incumbent drift has been exposed.[129-A]