ON GRANITE^ 23 \ 



*he line of feparation between a mafs of granite and the fchif- 

 tus incumbent upon it, all around a tract of country, about 

 eleven miles by feven, extending from the banks of Loch Ken, 

 wefiward ; and in all this tra& they found, " that wherever 

 the junction oi the granite with the fchiftus was vifible, veins 

 of the former, from fifty yards to the tenth of an inch in width, 

 were to be feen running into the latter, and pervading it in all 

 directions, fo as to put it beyond all doubt, that the granite whichMr. Hay- 

 of thefe veins, and confequently of the great body itfelf, which {^^wed'toa 

 was obferved to form with the veins one uninterrupted mafs, fofc ftate to their 

 *nuft have flowed in a foft and liquid ftate into its prefent po- prefentfitua- 

 fition *. I have only further to add, that fome of thefe veins 

 are remarkable for containing granite, not fenfibly different, 

 in any refpect, from the mafs from which they proceed." The The author ob- 

 Criffle in Galloway, which is one of the moft confiderable por-^ d fi ^ rifte 

 tions of what Dr. Hutton confiders as the granite of that 

 country, I found to be fienite, confequently it has no relation 

 to the old granite formation. ProfelTor Play fair, who exa- 

 mined the appearances at Loch Ken, believes with Dr. 

 Hutton, that fienite and granite, in a geognoftic point of view, 

 are to be confidercd as the fame f . From this I draw the and infers that 

 conclufion, that at Lock Ken we have a portion of the fame ' J' ot er gra 



' * nites are a por- 



lienite as that which forms the Criffle. tion of the fame. 



It appears then evident, that wherever granite, in the form The fame infc- 

 ©f veins is to be obferved iiTuing from granite into the con- j, en " £ encral: X 

 tiguous ftrata of gneifs, mica Hate, &c. it nmft belong to 

 a newer formation, and probably to that of Greifenflein. 

 Many of the inftances where fuch appearances have been ob-* 

 ferved, certainly belong to the fienite formation. 



It is therefore demonftrated t that Granite is the oldeft Rock zvith and that granite 

 which ive are acquainted. £* e oldeft of 



Before I conclude thefe remarks, I fhall notice two objec- 

 tions which have been urged againft the poffibility of granite 

 veins having been filled from above. Mr. Play fair obferves at 

 page 313, " that a ftrong objection to the fuppofed origin of To Profeflbr 

 granitic veins from infiltration, and indeed to their formation Playfair'sremark 



, . , r r -r r i , ^ tnat fragments 



jn any way but by igneous funon, antes trom the number of f fchiftus couid 



be iniulated in 



* Tranfaaions of the Royal Society of Edinburgh, vol.iii. p. 8. gr f ir L e * eins 



r oiuy by igneous 

 f Illuftration of the Huttonian Theory, p. 312. fufion j 



fragments 



