£5 



following classes : — I. Containing many ancient rocks derived 

 from doubtful or unknown localities. 2. Many primitive and 

 transition rocks resembling those existing in situ on the western 

 side of our island. Some of these which are much rounded 

 have probably, by an ancient catastrophe, been buried in the 

 conglomerates of the new red sandstone ; and afterwards, by 

 the last catastrophe which has desolated the earth's surface, 

 been transported into their present situation. 3. A fine series of 

 specimens of mountain limestone and trap resembling the cor- 

 responding rocks of Derbyshire and Staffordshire. 4. An 

 immense number of blocks drifted from the more recent strata. 

 Out of this class one might select a good series of specimens 

 characteristic of all the strata of England from the lias to the 

 chalk. 



Extensive deposits of diluvial rubbish similar to those last 

 described occur in two or three places to the east and south-cast 

 of Cambridge. From the gravel on the top of the Gogmagog 

 hills, I have found rolled masses of granite and porphyry ; 

 pebbles resembling those imbedded in the new red sandstone ; 

 masses of trap and mountain limestone ; and a fine series of 

 specimens derived from the oolitic formations. Masses of gravel 

 of a nearly identical character lie scattered over several parts of 

 the downs of Suffolk and Norfolk.* We must not imagine that 

 the instances here given are indications of mere local operations. 

 The gravel about Cambridge not only agrees in general charac- 

 ter, but almost forms a continuous mass with the beds of gravel 

 which are spread over many parts of the counties of Bedford- 

 shire, Huntingdonshire, and Northamptonshire. And the 

 patches of coarse diluvium which are scattered over the downs, 

 are connected with a series of operations which have buried 

 nearly the whole county of Norfolk and the greater part of the 

 county of Suffolk under enormous masses of diluvial debris. 

 Effects such as these are utterly beyond the reach of any known 

 natural agent. 



Plains of Cheshire, and Derbyskite Hills, £>r. 



TI. I intentionally pass over all details connected with the 

 history of the transported materials in the great plain of the new 

 red sandstone, and shall content myself with stating, that enor- 

 mous masses of diluvium extend from the base of the great 

 oolitic terrace through many parts of Leicestershire and Staf- 

 fordshire, and through almost every part of the plains of 

 Cheshire. The diluvial wreck of this region is found at all levels, 

 for it is seen on the upper part of Charnwood forest as well as in 

 the neighbouring vallies ; and transported bowlders of consider- 

 able magnitude occur at the very top of several parts of the 



* For some further details connected with this subject, see Prof. Hailstone'i paper in 

 the Geol. Transac. vol. iii. p. 244. 



