358 



ME. W. HILL Olf THE LOWEE BEDS OP THE TJPPEE 



the Eed Eock at Speeton ; while the proportion of carbonate of lime 

 is at Hunstanton 83-81 per cent., it is at Speeton only 45-00 and 

 59*60 per cent, in the lower and upper parts respectively. 



It appears also that the lower part of the Eed Chalk at Speeton 

 is even less calcareous than the Upper Gault of West jS'orfolk at 

 Eoydon and Dersingham or that of Pancourt, Bedfordshire, while 

 the upper part at Speeton will compare with the pink Gault of 

 Grimston and Dersingham. 



General tabular view of analyses of tlie Gault of Norfolk and 



tlie Hunstanton Limestone of Norfolk, Lincolnshire, 



and Yorkshire. 



Insoluble siliceous 1 

 matter J 



Carbonate of lime 



Oxide of iron and"! 

 alumina J 



Carbonate of magnesia 



Other matter 



Pink Gault. 



Dersingham, 



Is^rfolk. 



Eed Chalk. 



Hunstanton, 



iS^orfolk. 



Eed Chalk. 



Donnington, 

 Lincolnshire. 



Eed Chalk. 

 Speeton, Yorkshire. 



Upper. 



Lower. 



25-70 



64-49 



4-96 



1-82 



3-53 



7-50 



83-81 



7-39 



-62 



1-20 



4-49 



90-56 



3-52 



i-10 

 1-08 



24-60 



59-60 



4-80 



8-46 

 2-54 



42-40 



45-00 

 10-20 



1-51 



•89 









The admixture of siliceous material with the chalky deposit 

 does not end with the Hunstanton Limestone at Speeton, as the 

 analysis of a piece of the bluish-grey chalk of bed 2, taken about 

 4 ft. from the top of it, will show *. 



Speeton. g^^itMlrl. 



Insoluble siliceous matter 12-40 1 1 -98 



Oxide of iron and alumina 1-40 1-49 



Carbonate of lime 82-40 84-41 



Carbonate of magnesia 1-80 1-11 



Undetermined matter 2-00 1-01 



As wiU be seen, this analysis will compare with that of the upper 

 part of the Chalk Marl at Cambridge. 



That the deposit becomes purely calcareous is shown by the 

 analyses of a specimen taken from near the top of bed 3, where 

 the chalk is faintly tinted pink, and of the white chalk about the 

 middle of bed 7. 



Analysis of Bed 3. — Speeton, Yorkshire. 



Insoluble siliceous matter 5-40 



Oxide of iron and alumina -80 



Carbonate of lime 92-80 



Carbonate of magnesia -75 



Undetermined matter -25 



* I am indebted to Mr. J. W. Knights for this analysis. 



