Sometimes the lower beds have been eroded previously to the deposition of overlying beds, as in the following section at Ramsholt (fig. 6).
Fig. 6. — Section in the Red Crag at Ramsholt.
In one instance only have I seen ripple-marks preserved in the Red Crag. This occurred in the cliff at Bawdsey, where the argillaceous laminae of one bed retained each a ripple-marked surface, which in the section showed like the crumpled leaves of a book (fig. 7).
Figs. 7 & 8. — Sections in Bawdsey Cliff.
Fig- 7.
Laminae of ochreous clay and of shelly sand.
Fig. 8.
Bed of laminated clay and sand (b) with cracks at top filled with clay from a.
Another feature noticeable at times in the same cliff shows that probably the shoals of the Red-Crag sea were occasionally left dry — their surfaces fissured by the sun and air, and the cracks filled with the materials of the bed afterwards thrown down upon them (fig. 8).
Elsewhere a crag-seam has been pressed down into an underlying bed, and the upper part afterwards removed as in fig. 9.
Fig. 9. — Section in Bawdsey Cliff.
Ochreous clay.
(Crag in hollows on top of bed of grey clay with seams of ironstone.
Crag. Ochreous clay.
The oxide of iron, to the presence of which the Red Crag owes its distinctive name, is at places so abundant as to give rise to
2 a 2
