I had always been told that large bones were occasionally found in these clays ; but it was not until this last winter that any were brought to my notice, when I was informed that the bones of some large animal had been discovered ; and on visiting the pit in company with Mr. Gwyn Jeffreys, I was shown the vertebral column of a great whale at a depth of 8 feet from the surface, and lying at right angles to the face of the section. These vertebrae were exactly in the position in which they might have been left at the death of the animal — each vertebra lying a few inches apart from its neighbours, owing to the removal of the cartilaginous matter between them. About seven vertebrae have been taken out ; and it is to be hoped that a further portion of the skeleton may yet be discovered *. Fig. 19 is a sketch of this pit.
As this clay forms an important link in the correlation of the Suffolk with the Norfolk Crags, I will, before touching upon the latter, proceed to trace it from south to north through the Red-Crag area.
Commencing at the furthest point south, the bed of clay (see fig. 12, bed 3) overlying the sands at Walton-on-the-Naze should probably be referred to this zone. In mineral character it closely resembles the Chillesford clay ; and it contains in places, as it does again further north, fragments and pieces of wood, but I could here find no traces of shells. In the Ipswich and Woodbridge districts this clay is not seen, and the gravels of the Boulder-clay series repose immediately upon unproductive Chillesford sands or on the Crag. The clay is met with on the hills in the neighbourhood of Felixstow, and again near Hollesley ; but it is at Chillesford that it is best developed and becomes fossiliferous. It may be traced capping the hills between Sudbourne and Iken. Some time since, there was a good section in a pit half a mile north of Black Walks, in the direction of Iken. A laminated clay, 8 or 10 feet thick and full of the casts of the following shells, there overlies a bed of light-coloured sands, under which, at a depth of a few feet, the Red Crag was reached in a trench I had dug : —
Cardium groenlandicum. Nucula tenuis.
Leda myalis. Tellina lata.
And in the same clay at the pit at Low Farm we found : —
Cardium groenlandicum. Scobicularia piperata.
Leda myalis. Turritella communis.
Nucula Cobboldiae.
There was formerly a pit on Webber's Whin Farm, a mile and a half W.S.W. from Aldborough Ferry, where the fossiliferous Chillesford sands occurred, and with them a group of shells to which elsewhere special attention has been directed by Mr. Fisher†, by whom this bed has been termed the Mya-bed, from the abundance
- Dr. Crisp has since ascertained it to be an entire whale 31 feet long. (Brit.
Assoc. Rep. 1868, Trans. Sect. p. 61.)
† " On the Relation of the Norwich Crag to the Chillesford Clay or Loam " (Quart. Journ. Geol. Soc. vol. xxii. p. 19).
