114 PROCEEDINGS OP THE GEOLOGICAL SOCIETY. 



4. " Evidence furnished by the Quaternary Glacial-Epoch Mo- 

 rainic Deposits of Pennsylvania, U.S.A., for a similar mode of 

 formation of the Permian Breccias of Leicestershire and South 

 Derbyshire." By William S. Gresley, Esq., F.G.S. 



[Abstract.] 



In 1885 the writer communicated a paper to this Society* on 

 certain fossiliferous nodules and fragments of haematite occurring in 

 the Permian Breccias of Leicestershire ; and, pointing to the fact that 

 many of these nodules &c. were more or less covered with scratches, 

 and occasionallj' exhibited polished surfaces other than slickensides, 

 he had reasons for supposing, with Pamsay, that such markings 

 were, in some way, the result of ice-action at the close of the Coal- 

 Period. 



Since that paper was written some large subaugular, grooved or 

 striated boulders of sandstone, about a ton in weight, have been met 

 with in the workings of a coal-mine in South Derbyshire, lying 

 immediately upon eroded Coal-measures, in Permian Breccia-beds, 

 at about (300 feet deep. 



Spread over the denuded Coal-measures in the anthracite regions 

 of Pennsylvania, U. S. A., filling buried valleys and as morainic 

 heaps on more elevated surfaces, are large and often thick irregular 

 deposits of debris of rocks of various geological horizons, but chiefly 

 Coal-measures (conglomerates, grits, sandstones, slates, shales, coal, 

 fireclay, and ironstone), of all sizes up to hundreds of tons, mixed 

 with clay and ground-up materials. Immediately below this drift 

 excellent examples of glacial strice are frequently found, in situ, 

 upon the rocks; and some large "pot-holes" (one 48 ft. wide by 

 38 ft. deep) have been found in shallow excavations, which were 

 met Avith incidentally in the ordinary course of mining the 

 anthracite t- Probably no geologist questions the origin of these 

 surface-accumulations, namely, that they are of " the Glacial 

 Period.'' 



The nodules of ironstone occurring in these Glacial deposits in 

 Pennsylvania are scratched or striated in precisely the same manner 

 as arc those in the Permian deposits of Leicestershire and Derby- 

 shire ; in fact, except for colour, which goes for little or nothing, 

 one could not tell one specimen from the other. Furthermore, these 

 ironstones have been much more scratched than any other kind of 

 rock-fragment in both the English and American deposits. We 

 may satisfactorily account for this circumstance when we reflect 

 that, putting coal and clay on one side, the ironstone nodules would 

 suffer most in this respect, especially as the siliceous fragments 

 largely predominate, and are not often visibly affected that way. 



It cannot be supposed that these ironstone nodules in North 

 America were scratched previous to the Quaternary Period, but 

 those of the English Permian were previous to that epoch. We 



* Quart. Journ. Geol. Soc. vol. xli. Proceed, pp. 109, no. 



i" See ' Creological Survey rennsylrauia,' Annual Eeport 1885. 



