OF PAPA STOUR. 173 



cast side of Olisvoe, it is in the form of a conglo- 

 merate ; the cement and the fragments cemented, 

 being both of the same composition *. At the 

 east side of the Kirk-sand, it seems to lose in some 

 measure its slaty structure, and to pass into por- 

 phyritic -clay stone. At Culliesvoe, it is of a 

 greyish-black colour, the felspar in small quanti- 

 ty, and presenting the appearance of certain va- 

 rieties of porphyry-slate ; and on the west side of 

 the same voe, it is compact, of a red colour, and 

 full of minute grains of quartz. It is intimately 

 connected with the claystone, compact- felspar, 

 amygdaloid, and breccia rocks. 



All the rocks enumerated above, are traversed 

 by veins filled with calc-spar, heavy-spar, quartz,, 



* Three kinds of Conglomerate have been mentioned a- 

 bove, viz. Compact-felspar Conglomerate; Claystone Con- 

 glomerate ; and Porphyritic -slaty-felspar Conglomerate, 

 This occurrence does not seem to warrant the conclusion, 

 that the beds of felspar, claystone, and porphyritic-slaty- 

 felspar, owe their origin to rocks of a similar kind, 

 but much more ancient, and belonging to a different or- 

 der of things *, but rather support the conclusion, that 

 disturbances have taken place in the fluid, during t,he pe- 

 riod of deposition, of sufficient extent, to break into 

 fragments, portions of the new-formed rocks ; and that 

 the individual beds of the series have been frequently 

 repeated. This may serve also to explain the occur- 

 rence of the breccia at Bordie, in unconformable stratifi- 

 cation, and covered also with compact-felspar. 



