ON GROOVES AND QUARTZITE ROELDERS AT DUKINFIELD. 599 



40. On Grooves and Qtjartzite Boulders in the Roger Mine at 

 Dukinfield. By James Radcliffe, Esq., E.G.S. (Eead 

 March 23, 1887.) 



The Roger Mine, shown on Ordnance sheet no. 105, six-inch scale, 

 of Ashton-under-Lyne and Dukinfield, is extensively worked at 

 Denton, Dukinfield, Ashton-under-Lyne, and in the neighbourhood 

 of Oldham. 



At Dukinfield coal is being worked at a depth of five hundred and 

 fifty yards, and averages about four feet in thickness. Quartzite 

 boulders have from time to time been found in this mine, and have 

 been noticed on various occasions in communications to the Man- 

 chester Geological Society, in vols. xiii. and xiv. of their Transac- 

 tions. 



The groovings and boulders are not found in any mine or strata 

 in this neighbourhood, except in what is known as the Roger Mine, 

 which lies near the top of the middle series of the Manchester 

 coalfield. Rut occasionally quartzite pebbles have been found by 

 Mr. G. Wild, of Bardsley, in the Arley and Pomfret Mines. The 

 single groovings vary in depth from a few inches to eighteen inches, 

 and in width from one foot to three feet. Occasionally several of 

 these grooves run close together, and then widen out into one broad 

 " scour,"or groove, of fifteen or even eighteen feet wide, as if the 

 base of a large moving body had come in contact with the upper 

 surface of the coal-bed. These grooves have been traced at intervals 

 over a distance of from five to six hundred yards in length, and from 

 fifty to sixty yards in width. 



The Roger-Mine seam of coal is composed of three divisions: — - 

 the " upper," a soft, bright, free-burning coal ; the " middle," or 

 " bony-band," a hard, dull, stony-looking coal ; the " lower," or 

 bottom bed, a dull-looking coal with two partings. The dip of the 

 measures is west, and has an inclination of 18 degrees. The 

 mean line of bearing of the grooves is S. 50° E. ; line of fault-slips 

 &c. is S. 26° W. The line of the grooves is not connected with, 

 nor is it nearly parallel to, any fault or fault-slips. There are no 

 faults or dislocations of the strata for a considerable distance from 

 where these grooves are seen. ~No fossil trees or specimens of 

 Stigmaria Jicoides are found with the boulders, or in the immediate 

 neighbourhood of the grooves. The cleavage of the coal is about 

 S. 15° E. 



All the fault-slips, joints, &c. come upwards through the floor 

 beneath the coal, through the coal, and into the roof overlying the 

 coal, which is not the case with the grooves ; these are not seen in 

 the floor, nor do they ever reach the bottom of the coal ; they rarely 

 extend to the middle coal, the " bony-band " being undisturbed 

 except in two cases I noticed : one in the form of an undulating 

 ridge in the " bony-band " on one side of the groove, as if caused by 

 pressure from the centre of the groove, which, being in the upper 



