94 THE UNCONFOEMITr Ilf THE [Feb. I9OI, 



The remarkable phenomenon of the Symon ' Pault,' as originally 

 described by Marcus Scott, had keenly interested geologists from 

 the first ; and his suggestion that it was due to a mere local 

 <ienudation-valley had since been largely corrected and amplified 

 by Mr. Daniel Jones. But the Author of the present paper was 

 the first to demonstrate, by actual plotted sections, that in the 

 Coalbrookdale Coalfield the Symon * Fault " is a phenomenon of 

 folding as well as of broad denudation. 



The transitional period of time between the deposition of the 

 typical Middle and Upper Coal-Measures had long been recognized 

 by Midland geologists as one of more or less regional upheaval and 

 denudation ; and abroad this special inter-Coal-Measure period of 

 crust-movement was described by Prof. Suess and others as one 

 of the grandest in geological history — namely, that of the great 

 Hercynian movement : the mountain-making period of the Harz, 

 the Alleghanies, and the Armorican chains. 



It was of extreme interest to note from the Author's sections that 

 the Coalbrookdale crust-creep, although Armorican in date, so to 

 speak, was Caledonian in direction. There was much to be said also 

 in favour of the Author's opinion that other parallel and similarly 

 denuded folds of Caledonian trend affect the Middle Coal-Measures 

 under the Red Rocks of the Midlands, and that consequently the 

 presence of Upper Coal-Measures affords no certain guarantee that 

 Middle Coal-Measures actually occur below. Unfortunately, this 

 was only one danger among many. The Coal-Measure Period 

 as a whole was one of crust-movement, and there is evidence of this 

 in the four usual directions. Though the predominant movement 

 in the Coalbrookdale Coalfield was from the north-west, in the 

 Bristol-Channel region the Armorican creep made itself most felt ; 

 whereas in other parts of England, as locally in the Midlands, 

 sometimes the Charnian, and sometimes the Pennine creep has the 

 greatest effect. Careful observations and conclusions, such as those 

 of the Author, made by mining-engineers and bringing out the 

 dominant local directions of movement, are certain to prove of 

 great assistance in opening out the hidden coalfields of our 

 country. 



Prof. Groom expressed his gratification that the Author's results 

 were in harmony with the views which he (the speaker) had pre- 

 viously expressed. He congratulated the Author on obtaining a 

 much-needed clue to the age of the north-easterly and south-westerly 

 folds of the Welsh Border. It was necessary, however, to recognize 

 that all the British folds parallel to this direction were not of the 

 same age. A considerable part of the British Isles appeared to have 

 been built up at different periods by successive addition of zones of 

 plication, each lying south-east of its immediate predecessor. 



The Eev. J. F. Blake enquired whether there was any Spirorhis- 

 limestone, or underclay beneath the coal in the Upper Measures here, 

 since otherwise Prof. Hull's suggestion of their possible classification 

 with the Permian might be correct. But, assuming them to be true 

 Upper Coal-Measures, the Author had drawn them horizontal and 

 spoken of a plane of denudation of the Lower Measures ; while 



li 



