454 Wood and Earmer — Geology of Norfolk and Suffolk, 



present when in its pure condition. This sand passes up by inter- 

 bedding into : — 



B. — The Cromer Till, or '* Lower Boulder-clay" of Mr. Gunn, a 

 sandy clay with numerous small stones, and with occasionally a 

 boulder of larger dimensions. 



c. — Sands which, where the cliff is uncontorted, are seen to be 

 indented into a deeply eroded surface of the Till, and to have them- 

 selves been also denuded, so as to form an even floor for the ensuing 

 formation, viz., 



D.— The Contorted Drift. This bed is the widest spread of the 

 Lower Glacial series. It begins in the north of Suffolk as a red- 

 dish brown brick-earth, a few feet thick, resting on the sands 

 with pebbles, before described, but sometimes the pebbly sands 

 have been removed. It comes up at the base of Pakefield and Corton 

 cliffs (where, as well as in the sections at Bishops Bridge, Norwich, 

 it is called by Mr. Gunn and others " Lower Boulder-clay,") and 

 thickening rapidly as it extends northwards, comes out at the eastern 

 termination of the Cromer coast section at Eccles, as the well-known 

 Contorted Drift of that coast, from whence it extends continuously, 

 and as the uppermost bed of the cliff (except the sand cappings) to 

 Weybourne. The authors state that they have traced it from its 

 attenuated commencement in the north-east of Suffolk and south- 

 east of Norfolk in every direction northwards, and found it at 

 Cargate Green, near Acle (ten miles only south of the Cromer coast), 

 overlaid by the great Boulder-clay (or tipper Glacial) , and at West 

 Somerton (seven miles south-east of the Eccles termination of the 

 coast section) overlaid by Middle Glacial sand, and that again by 

 the great Boulder-clay in direct superposition. In its brick-earth 

 condition it is sometimes full of small stones, occasionally also of 

 minute chalk fragments, and often contains large sand-galls. In 

 the direction of Weybourne this deposit becomes more marly by the 

 intermixture of fine chalk sediment; and west of Mundesley, at 

 which place it begins to be contorted, gi-eat masses of pure white 

 marl or reconstructed Chalk (which have been described as chalk- 

 masses by observers,) occur in it, which, by the weight of the bergs 

 carrying them, have sunk in some cases into the subjacent Till, and 

 even into the Weybourne sand. These marl masses the authors 

 describe as being detached fragments from the more inland portion 

 of the Contorted Drift itself ; which, inland from the coast, both 

 southwards towards Keepham and Holt, and westwards towards 

 Wells, becomes formed exclusively of this marl. They attribute the 

 formation of this marly portion of the Contorted Drift to a discharge 

 of ground-up Chalk from the dehoucJiiire of a Glacier that occupied 

 the Chalk country of Cambridgeshire and West Suffolk ; the brick- 

 earth which forms the easterly development of the Contorted Drift, 

 being due to a river discharge in tliat part ; the two sediments inter- 

 mingling in the intermediate area, and producing the alternations of 

 marl and brick-earth there presented by this formation. The de- 

 tached masses of the marl were, they consider, introduced into the 

 brick-earth portion of the deposit by the agency of bergs, which, 



