Mr. H. Seeley on the Red Rock in the Section at Hunstanton. 73 



observed that it is an elevated semi-desert region, composed of a 

 succession of longitudinal mountain-ranges with intermediate valleys 

 and plains, the most abundant rocks being Metamorphic and 

 Igneous; but Tertiary strata and Carboniferous Limestone also 

 occur. 



The author then described the hot springs, which are extended 

 along a line of fissure in a granitic rock, and parallel to the moun- 

 tains, and which deposit silica in an amorphous and a granular 

 state, sulphur being also seen in the cracks and cavities of the sili- 

 ceous deposit. He considered these phenomena to illustrate the 

 formation of a quartz-vein in a fissure. 



Mr. Blake then gave an account of certain mineral veins in por- 

 phyry, which yield sulphurets of silver (including crystals of Ste- 

 phanite, but very little ruby silver) and a little gold ; also galena, 

 copper pyrites, iron pyrites, and a little native silver, the veinstone 

 being a friable quartz. The prevailing direction of the veins was 

 stated to be nearly north and south ; and the author remarked that 

 they were richer in gold near the surface than at greater depths. 



2. " On the Red Rock in the Section at Hunstanton." By 

 Harry Seeley, Esq., F.G.S., of the Woodwardian Museum, Cam- 

 bridge. 



The physical structure of the rock was first considered, and it was 

 shown to be divisible into three beds, the uppermost of which is of a 

 much lighter colour than the rest, the middle being concretionary in 

 structure, and the lower sandy. These three beds, with the over- 

 lying white sponge-bed, were considered to belong to one formation, 

 and were treated of in this paper as the Hunstanton Rock ; but the 

 thin band of red chalk some distance above was considered, though 

 of similar colour, to be quite distinct, as also was the Carstone 

 below. 



Mr. Seeley then showed that near Cambridge the Shanklin Sands 

 and the Gault have both become very thin, so that there is a great 

 probability of the latter being unconformable to the beds above as 

 well as to those below. He considered the lower part of the Car- 

 stone to be of the age of the Shanklin sands; and as the Chalk is 

 not unconformable to the Hunstanton Rock, he concluded that the 

 latter could not be the Gault, but must be the Upper Greensand, — 

 a conclusion which he afterwards showed was supported by the 

 evidence of the fossils, and the occurrence of phosphate of lime. 



The seam of soapy clay which separates the Hunstanton Rock 

 from the Chalk was supposed to have resulted from the disintegra- 

 tion of a portion of the former, the red colour of 4 which the author 

 endeavoured to show was due to Glauconite. 



The upper part of the red rock of Speeton was thought to be 

 possibly newer than that of Hunstanton, and perhaps to represent 

 the time which elapsed between the formation of the latter and that 

 of the band of red chalk. 



In conclusion, Mr. Seeley remarked that as the phosphate of lime 

 is confined to Bed No. 2, and as many individuals of Gault species 

 occur in Bed No. 3, while others of a Chalk character are met with 



