188 Reports & Proceedings — Edinburgh Geological Society. 



was a pause during which fiae-grainedandesite tuffs, with a tendency 

 to produce true slates, accumulated. This was succeeded by a vast 

 outpouring of andesites, of great thickness in the central mountain 

 region, but dying out southwards and eastwards. Next a series of 

 peculiar mixed tuffs, of special value in mapping, was covered by 

 another mass of andesites dying out south-westwards. After this, 

 soda-rhyolites covered the whole district, nothing later being 

 preserved — with one possible known exception. These volcanic 

 rocks were intersected by a varied series of intrusions. 



The solfataric phenomena were of interest, including the pro- 

 duction of garnet and graphite, and a remarkable "streaky'^ 

 structure in the rhyolitos. 



An important question related to the age of the large acid 

 intrusions associated with the volcanic rocks. Were they of the 

 same age as, or later than, the Devonian folding ? A sketch was given 

 of the evidence on which the Lecturer assigned the Eskdale and 

 Skiddaw granites to the Ordovician volcanic episode, and it was 

 suggested that the great Skiddaw anticline was not due to regional 

 folding, but a local structure connected with the vulcanicity. 



Lantern-slides of Lake District country were shown, and the 

 manner in which the volcanic rocks entered into the scenery was 

 pointed out. 



II. — Edinburgh Geological SociExr. 



February 20, 1918. — Professor Jehu, President, in the Chair. 

 (Issued March 16, 1918.) 



1. " Coal Apples." By J. Masterton, H.M.I. M. 



At the Lochend Pit of Longrigg Colliery, Longriggend, in the 

 Upper Drumgray Seam, which is there anthracitic, Mr. Masterton 

 found in 1910 rounded balls of coal from 1^ inches to 5 inches 

 diameter, and occasionally up to 8 inches diameter. The balls were 

 slickensided, and, when seen in situ, the surrounding coal matter 

 was sometimes slightly displaced. The larger balls, when broken, 

 had a strong likeness to cone-in-cone coal. The late Dr. Clough was 

 shown the balls, and he drew attention to a note in the Transactions 

 of the Glasgow Geological Society recording the discovery of similar 

 balls in North Ayrshire by Mr. John Smith. Mr. Smith found the 

 balls near a whin float. 



The apples in Lochend Pit occur in an anthracitic coal, and 

 Mr. Masterton found similar balls in most of the pits near Lochend, 

 both in the Upper and Lower Drumgray Seams. The whin float 

 which underlies the Slamannan District has been proved by bores, 

 and is seen at the surface near Forrestfield, to the south of the 

 Lochend Pit ; it has almost certainly both anthracitized the coal and 

 formed the apples, and Mr. Masterton cannot accept Mr. Carruthers^ 

 assertions in the Geological Survey's publications as to the formation 

 of the anthracites in the area in question by agencies similar to those 

 to which the anthracitization of the coals of South Wales has been 

 ascribed. 



