llBPORT OF THE MEETINGS EOR 1896 6l 



pebbles, mostly of the size of one's fist, but some of which are 

 5 or 6 inches in the longer diameter, and very much rounded, 

 evidently by water. Of these several are White Quartz such as 

 might be derived from the Mica Slates of the Grampians, others 

 are Clay Slate similar to that of Comrie, etc., but the greater 

 proportion are of Granular Quartz rock, very much resembling 

 that of Ciunie, the Dee above Braemar, Glen Tilt, on the Falls 

 of the Tummel. The Conglomerate is very hard (from 

 subsequent metamorphic action) the interstices between the 

 pebbles being occupied by a hard bluish Greywacke, once a 

 moderately coarse sand. The stratum is vertical, or nearly so, 

 and conformable to the strata with which it is associated, which 

 strike N. by E. to S. by W. The strata on the west side are 

 slaty, and on the east coarse grained Greywacke, very hard. 

 The Conglomerate bed appears to be about 4 yards wide. The 

 circumstances under which this remarkable rock was formed 

 and the precise localities whence its component parts were 

 derived are questions of much interest. It differs from the 

 other Conglomerate beds of the Greywacke in the far larger size 

 of the water-worn fragments which it contains, as well as in 

 the greater part of these being Granular Quartz, the Quartz of 

 the other beds of Greywacke Conglomerate with which I am 

 acquainted among the Lammermuirs being of the pure white 

 compact variety, and the fragments never exceeding horse 

 beans in size. The bed in question appears to be local, and I 

 rather think occupies the same or nearly the same, place in the 

 Greywacke system as the other beds referred to. No Granular 

 Quartz occurs nearer this place than the localities above 

 enumerated and the islands of Jura, Islay, etc. It must 

 therefore be presumed to have been brought from some one of 

 these places, unless we suppose a tract of land of which White 

 Sandstone or Granular Quartz was a constituent rock, to have 

 occupied the space, or a part of it, which intervenes between the 

 Grampians and Lammermuirs, and which is now a great 

 depression. Perhaps a large river flowing from the primary 

 lands to the westward and discharging its waters into the 

 ocean about this place may have brought the boulders in 

 question and thrown them down at this spot. I rather incline 

 however to the opinion that the fragments in question are all 

 that remains of some island of Granular Quartz rock (itself the 

 remnant of a more extensive formation) which resisted the 



