QTTARTZITE B0T7LDEKS IN THE EOGEE MINE AT DTJEINFIELI) . 603 



Ko. 1, but perhaps with a shade more earthy matter among the 

 grannies of qnartz. We find the same adventitious minerals." 



]STo. 5 boulder weighs five pounds. " A grit somewhat resem- 

 bling No. 2, or intermediate in character between it and No. 3. 

 Fragments rather distinctly angular. I recognize some felspar by 

 its plagioclastic twinning, but a good many of the grains suggest 

 either an argillite or a decomposed rhyolitic rock. There are gran- 

 ules and specks of iron-oxide, two or three grains of tourmaline, and 

 a few flakes of mica." 



No. 6 boulder weighs thirty-one pounds. " A quartz-grit, rather 

 ferrite-stained ; grains rather variable in size and shape, the larger 

 and rarer about '025" diameter. The quartz, besides minute cavities, 

 contains occasional belonites, rutile (?) ; one or two grains are chalce- 

 donic. There are also grains of iron-oxide, epidote and torvrmaline 

 (rare), and flakes of mica and, as before, a few fragments of de- 

 composed felspar (?). 



" In more than one of these specimens secondary quartz can be 

 seen, deposited in crystalline continuity with the original fragments. 

 Nos. 1 and 4, especially,, bear a very close resemblance to the rock 

 of a quartz.ite pebble found by Mr. Gresley in a coal-seam in Leices- 

 tershire, and to that of a large pebble taken out of the thirteenth 

 coal at the Cannock-Chase Colliery near Rugeley. 



" These quartzites present considerable resemblance to the rocks 

 of some of the pebbles in the Bunter conglomerate of the midland 

 counties, in which occasional grains of tourmaline, and of the mineral, 

 which I have identified as probably epidote, may be found. 



" They also resemble some of the quartzites in the Loch-Maree 

 district, in which also these two minerals may be detected." 



Discussion. 



Mr. W. W. Smyth said the occurrence of the boulders was an in- 

 teresting phenomenon, on account of the absence of pebbles generally 

 throughout the Coal-measures above the Millstone Grit. Only now 

 and then, throughout the enormous area of coal daily raised, some of 

 these boulders were unearthed. The boulders are worn on the 

 surface, polished and sometimes striated. He had seen, in company 

 with the late Mr. Binney, a number of these boulders, some with a 

 coating of coal, others partly coated with a film of iron pyrites, just 

 like some slickenside surfaces. One popular explanation was that these 

 boulders were meteorites, an utterly untenable supposition. He had 

 never seen one of these boulders actually imbedded. The whole 

 subject so far appeared to be very obscure. 



Prof. Boyd Dawkins said such boulders were far from uncommon 

 in parts of Lancashire, and all appear to be of a very similar quartzite 

 to the specimens exhibited. The grooves were not necessarily con- 

 nected with the boulders. The upper surface of a coal-seam was 

 generally uneven, and often showed denudation by water. He had 

 seen remarkable markings made apparently by snags. He was 



