MINERALOGICAL QUERIES. 119 



18. What are the geognostic characters and 

 relations of the ores of Sandlodge in Shet- 

 land ? 



1 



29. Does the claystone, &c. of Papa Stour, one 

 of the Shetland islands, belong to the newest 

 flcetz-trap or to the coal formation ? 



I have described the claystone and other simi- 

 lar rocks of Papa Stour, under the name wacken in 

 my account of that island, because wacken and clay- 

 stone were formerly considered by mineralogists 

 as varieties of the same species. The occurrence 

 of this rock, along with a kind of tuff resembling 

 that found in the flcetz-trap formation, would in- 

 cline me to consider it as belonging to the trap 

 formation, did not its intimate connection with 

 the sandstone which forms the base of the island, 

 (and which does not appear to belong to the new- 

 est flcetz-trap, but rather to the independent coal 

 formation, or some of the particular sandstone for- 

 mations), seem to refer it to the coal or sandstone 

 formations. Data are still wanting for the deter- 

 mination of this interesting point 



* Since this query was proposed, the Reverend Mr 

 Fleming, in a paper read before the Society, refers this 

 claystone. and its accompanying rocks, to the coal formsu 

 lion, 



