RED CRAG. 
73 
In 1839 LyelP followed Mr. Charlesworth as to the super¬ 
position o£ the Red on the Coralline Crag, the former resting on a 
denuded surface of the latter ; and described the junction of the 
two at Sutton, where the Coralline Crag has been perforated by 
Pholas, and in parts forms a low buried clift’ against which the 
Red Crag rests. He describerl the so-called Fluvio-marine Crag 
of Southwold, but seems to include therein the overlying pebbly 
sands at Easton Bavent clitf, and treated of the Norwich Crag at 
greater length. He accepted the opinion of Desnoyers that the 
Red and Coralline Crags may be of the same age as the Faluns of 
Touraine, as, though the fauna of the former is of a northern 
character, whilst that of the latter is southern, yet tlie two faunas 
depart almost equally from the nearest existing marine fauna. 
He regarded the Norwich Crag as older Pliocene, the Red and 
Coralline Crags as Miocene. 
In the same year S. V. Wood commenced his papers on the 
fossil shells of the Crag; these he afterwards expanded into the 
valuable Monograph published by the Palseontographical Society 
between the years 1848 and 1882. In the Introduction to the 
first part of his Monograph Wood classes the Coralline Crag as 
Miocene, the Red Crag as Pliocene, and the Mammaliferous Crag 
as Pleistocene. 
In 1849 Prof. Prestwicht established the fact that the fossili- 
ferous clay and sand of Chillesford overlie the Red Crag, and 
sometimes overlap on to the Coralline Crag. These Chillesford 
Beds were, he thought, the result of tranquil accumulation, whilst 
the Red Crag showed every sign of a disturbed condition of the 
waters. He gave a list of pits in Coralline Crag, in Red Crag, 
and in Chillesford Clay, between the Aide and the Butley River. 
In 1852 Lyellf noted the occurrence, near the top of the 
shelly Crag at Wherstead, of a bed of unrolled flints, with some 
flint-pebbles, the upper parts of the stones being encrusted with 
barnacle-shells, whilst the lower surfaces are free, and inferred 
that the action of the currents which brought the Crag here was 
suspended for a time, so that the smallest pebbles were not over¬ 
turned, as otherwise the barnacles would be found on the lower 
side or on both sides. 
The first paper on the Crag by S. V. Wood, jun., appeared in 
1864.§ The Red Crag is divided by this author into two parts, 
one with none of the characters of a deposit formed under water, 
the other with those characters. Of the former there are four 
stages (beach stages), whilst the latter is more or less horizontal. 
The lowest three stages of the beach Crag are not quite constant 
in their direction (that is, the direction of the so-called false- 
bedding), and cannot be well identified in different sections; but 
the uppermost stage, from its thickness and from its having been 
* On the Relative Ages of the Tertiary Deposits commonly called “ Crag,” in the 
Counties of Norfolk and Suffolk. Mag. Nat. Hist., ser. 2, vol. hi. p. 213. 
f Quart. Journ. Geol. Soc., vol. v. p. 345-353. 
j Mep, Brit. Assoc, for 1851, Sections, pp. 65, 66. 
I Ann. Nat. Hist., ser. 3, vol. xiii. pp. 185-203, pi. xvii. 
