1844.] 435 



8. On the Cliffs of Northekn Drift on the Coast of Norfolk, 

 between Wetbourne and Happisburgh. By Joshua Trimmer, 



Esq. F.G.S. 



In this paper the author proposes to describe certain changes that 

 have taken place in these cliffs, comparing the appearances they 

 present with those of raised beaches in North Wales, 



With regard to the former subject, he notices first, the condition 

 of a pinnacle of chalk at Old Hythe Point. The cavity at the 

 summit of this pinnacle is now exposed to a greater depth than in 

 Mr.Lyell's drawing*, and the sand and gravel with which it was 

 filled ai'e removed. No vertical strata of sand to the N.E. of the 

 pinnacle are now visible, and these must have been removed by 

 denudation. Mr. Lyell's statement that this pinnacle is separated 

 from the great mass of the chalk by the crag deposits is, in the 

 opinion of the author, confirmed by the position in which the 

 chalk rests. 



Of the protuberances of chalk near Trimmingham, the northern 

 and middle seem now little changed, but the southernmost has 

 undergone some alteration. Its length is still the same as when 

 visited by Mr. Lyell, but it is reduced to nearly half its height, 

 and the waves have washed away a portion of the overlying gravel 

 at one extremity. The next fall of the cliff will probably bury 

 this end of the protuberance entirely. The chalk inland seems 

 tilted, and is covered with a breccia of the crag. 



About a quarter of a mile east of Cromer, the author met with 

 a bed of peat, resting on pyritous silt and gravel, and resembling a 

 peat bed at Mundesly, and the stem of a small fir tree was here 

 observed in a vertical position. Between Mundesly and Trim- 

 mingham he observed other instances of peaty beds associated 

 with the same kind of gravel, and he endeavoured to determine 

 whether the till and the freshwater deposits were contemporaneous. 

 This he decided in the afiirmative, at least for the upper portion 

 of the freshwater beds, since at Cromer he found, at the height of 

 20 feet from the beach (about 300 yards west of the jetty), several 

 bands of black peaty mud, a few inches thick, alternating with 

 laminated blue clay, derived from an adjoining mass of the un- 

 stratified till, which elsewhere overlies the freshwater beds. 



At Runton, near the Gap, the freshwater beds are covered by a 

 regular marine deposit of the crag. A black peaty bed, about 4 

 feet thick, containing shells of Cyclas, Planorbis, Helix, and frag- 

 ments of Anodon, together with some vegetable remains, rests on 

 a ferruginous sand, containing Anodon. The peat is covered by a 

 bed of gravel about a foot thick, containing Fusus striatus, Telliria 

 obliqua, Mya arenaria, and Natica helicoides, and some of the 

 shells of Mya exhibit the valves united, but they are too fragile to 



* See Phil. Mag., May, 1840. 

 VOL. IV. PART II. K K 



