FASSNEY WATER. 101 



logist, however, who, without any preconceived notions 

 or blind adherence to any theory, examines the structure of 

 such chains as the transition range of the Lammermuirs will, 

 when he finds strata extending through immense tracts of 

 country fractured, and exhibiting flexures of great extent, 

 observe little which he can consider similar to the effects of 

 modern earthquakes. In the disturbances visible in moun- 

 tain chains, we can only discover proofs of energetic actions 

 which had not been subject to innumerable interruptions, 

 but were, on the contrary, of comparatively short duration. 

 Forming a considerable part of the bed of the Fassney 

 water, and also extending for a short distance down the 

 Whitadder, after the confluence of the two streams, an 

 unstratified rock occurs, exhibiting rather interesting cha- 

 racters. It is a highly crystalline aggregate of variously 

 sized concretions of felspar and hornblende ; black mica 

 in some places occurs, but is to be considered more as an 

 accidental mineral than a true constituent of the rock. 

 The felspar which enters into the composition of this rock 

 is in general of a flesh-red colour ; at other times, how- 

 ever, it is white or grey, and then the rock can only be 

 considered as an ordinary greenstone. The structure of 

 this syenitic greenstone is in general tabular, but in some 

 places it exhibits a globular arrangement ; the decompos- 

 ing influence of the atmosphere removing a softer and more 

 easily disintegrated rock, in which are imbedded concre- 

 tionary masses of a more compact and lasting variety. In 

 several places, this syenitic greenstone makes a transition into 

 compact felspar, and at the Keelstone pool it is traversed by 

 a broad and apparently contemporaneous vein of brownish- 

 red felspar. Veins of sulphate of bary tes, associated with the 

 green carbonate of copper and prismatic copper-glance, occur 



