29 
ANALYSIS OF THE EED CHALK OE HUNSTANTON, 
ON THE COAST OE NOEFOLK. 
By E. Calteet Clapham, Esq. 
During one of the excursions of the late meeting of the British 
Association at Cambridge, the red chalk of Hunstanton was exa- 
mined, and as I am not aware of its having been previously analysed, 
I obtained a specimen to analyse. 
The bed of red chalk is about 3^ feet thick, and runs along the 
coast, distinctly seen for some miles. It rests immediately upon the 
Greensand, and above lies a bed of white-chalk, varying in thickness 
from 25 feet downwards. 
Professor Phillips, of Oxford, informs me that this bed of red 
chalk has been traced from Speeton, in Yorkshire, to Spilsby, in 
Lincolnshire, and reappears at Hunstanton, in Norfolk. 
It contains many fossils, chiefly of the White Chalk, and also fossils 
of the Grreensand and Gault. 
It is an interesting question to consider what is the cause of 
colour in the red chalk. Professor Phillips thinks that it is derived 
from decomposed glauconite or decomposed augite (both of which 
contain protoxide of iron and magnesia). It may also be caused by 
decomposed iron pyrites, as it will be observed it contains a trace of 
sulphate of lime. 
At Speeton it is in some places a soft red clay, and is used to 
colour bricks and rough pottery. 
The followiug is the analysis : — 
Eed chalk. 
White chalk. 
Carbonate of lime . 
. . 80 04 
95-80 
Sulphate of lime 
. . 010 
trace only 
Peroxide of iron 
. . 9-60 
1-08 
1-42 
0-52 
Mnguesia .... 
. . nil. 
0-48 
. 9-28 
2-28 
0-11 
100-44 
100-27 
Walker, Neivcastle-on-Ti/ne, November, 18G2. 
COREESPONDENCE. 
Afjes of JSLineral Veins. 
Sir, — Upon reading your report upon Mr. Moore's paper on the " Pa- 
Iteontology of Mineral Veins, etc.," before the British Association, a cir- 
cumstance bearing upon the question occurred to my recollection, which I 
would have mentioned had I been present in the Section at the time the 
l^aper was brought forward. Mr. Moore shows that lead veins in the 
