146 GEOLOGY OF THE LOTHIANS. 



APPENDIX II. 



ON THE JUNCTIONS OF GREYWACKE AND SANDSTONE 

 WITH GRANITE AND SYENITE. 



In our memoir on the Geology of the Lothians, we have 

 observed that the Transition strata are in few instances con- 

 nected with the ignigenous rocks, and that even when such 

 relations are observable, they are seldom of an interesting 

 description. Other portions, however, of the great transi- 

 tion high land of the south of Scotland are related, in an 

 interesting manner, with plutonic masses. Trap and por- 

 phyry rocks in several places occur associated with the 

 strata, but a detail of the appearances exhibited by these i& 

 here inadmissible ; we shall, however, shortly notice a few 

 points where they are found connected with true granite 

 and syenite. 



The granitic rocks which rise through the greywacke 

 strata form three distinct and isolated groups, viz. that of 

 Criffel, Loch Ken, and Loch Doon. 



I. Criffel District.* 

 The first of these, near the village of New Abbey, rises 

 through the greywacke and attains in the hill of Criffel 

 to the height of 1830 feet. The granitic rocks of this 

 district do not consist entirely of true granite ; on the con- 

 trary, they vary much, some of the mountains being formed 

 of granite, while others are composed of a characteristic 

 syenite. None of these rocks, however, in their relations 

 to each other, indicate a difference in age, but bear impressed 

 upon them characters which prove a perfect synchronism 



" Vide Professor Jameson's Memoir on the Geognosy of Criffel, Kirk- 

 bean, and the Needle's Eye in Galloway, in the 4th volume of the Me- 

 moirs of the Wemerian Society. 



