MINERALOGICAL QUERIES 



III 



2* Does claystone occur in beds in the coal- 

 fields of the Lothians ? 



Claystone occurs in different parts of the 

 Lothians ; but it appears in general rather to rest 

 upon the coal-formation, than to form beds in it. 

 It may, however, occur in beds, as a similar rock 

 occurs in beds in the coal-formation of the 

 Plauischen-grunde between Tharand and Dres- 

 den. 



3. Are the geognOstic relations of the porphyry- 

 slate of East Lothian, similar to those ob- 

 served in that rock in other countries ? 



At the Girleton Hills near Haddington, the 

 porphyry- slate is associated with ciaystone-tuff 

 and probably also claystone, — rocks that are not 

 mentioned by Werner, as occurring along with 

 porphyry- slate in Saxony, Bohemia, and other 

 countries. This fact would incline us to con- 

 jecture, that the porphyry-slate of that district 

 has something peculiar in its geognostical charac- 

 ters. 



4. What are the geognostic relations of the 

 claystone, compact- felspar, and clinkstone, 

 of the Pentland hills near Edinburgh ? 



The fundamental rock of the Pentland hills, is 

 in some places grey-wacke and grey-wacke-slate ; 

 and the newer rocks, viz. those that lie over this 

 older rock, are conglomerate, claystone-tuff, trap- 

 tuff, claystone, compact-felspar, clinkstone, 

 porphyry- slate, and sandstone. I have not as yet 



