114 PEOCEEDINGS OP THE aEOLOGICAL SOCIETY. [Jan. 23. 



them together into a saccharoid mass insoluble in hydrochloric 

 acid. 



The beds of gravel including the blocks contain fragments of 

 marine shells, as Turritella, Oardium, Cyprina, &c., examples of 

 which I obtained from a gravel-pit near Hemingstone Church. 



Unless it can be proved that the coast Boulder-clay of Norfolk is 

 really older than that occupying the high ground of the eastern 

 counties, the gravel containing the consolidated blocks would appear 

 to be the lowest member of the Boulder-clay series in the east of 

 England. 



2. Notes on some Chemical An^altses of Yaetegated Stkata. 

 By Geokge Maw, Esq., E.G.S., E.L.S., &c. 



[The pubhcation of this paper is deferred.] 



(Abstract.) 



The author gave the results of some analyses for the determination 

 of iron in the light and dark parts of variegated slates, sandstones, 

 and marls, the colour of which is due to oxide of iron, and in which 

 the variegation appears to be disposed independently of mechanical 

 arrangement. The analysis in each case exhibited the fact that the 

 lighter blotches, spots, and stripes contained a smaller proportion of 

 the colouring oxide than the average mass, a proportion which implies 

 an actual difference in the percentage of the metallic iron, and 

 which could not be accounted for by any mere difference in the state 

 of its combination. This shows an actual departure of a part of the 

 colouring oxide out of the colourless patches, and a dispersive pro- 

 cess which seemed to be the very reverse of the segregation of 

 nodules of carbonate of lime and carbonate of iron out of a clayey 

 matrix. Among the forms of variegation referred to were : — (1st) 

 that resulting from the segregation of dark blotches out of a Hghter 

 matrix, the evenness of colour of which does not appear to have 

 been materially affected by the withdrawal of a part of its colouring- 

 matter ; (2nd) that resulting from the segregation of dark blotches 

 out of a lighter ground, each of which is concentrically surrounded 

 by a distinct and well-defined zone lighter than the general ground ; 

 (3rd) strata variegated with light blotches containing a smaller pro- 

 portion of colouring-matter than the general ground, but not ar- 

 ranged concentrically round a darker nucleus ; (4th) the variegation 

 of coloured strata with both light and dark blotches, containing 

 respectively a smaller and larger proportion of the colouring oxide 

 than the general ground, but which are not arranged, as in the 

 second case, concentrically with each other. 



