12 W. S. Gresley — A Modern Ferruginous Conglomerate. 



a kind of shell to the red ore, though occasionally the two kinds 

 exist in thin alternating bands. These hard haematite fragments 

 are sometimes partially composed of quartz grains, and the concentric 

 zones of oxidation seen upon the surface of the specimen run through 

 the gritty parts just as they do through those devoid of the quartz 

 grains. Other specimens observed should, I think, be termed iron- 

 jasper rather than classed as haematite. The remainder of the in- 

 cluded pebbles, etc., are chiefly those of quartzite and fine-grained 

 hard sandstones and slaty rocks of yellow, brown, and green tints ; 

 also small fragments of coal. The size of the fragments in the 

 deposit range from mere specks to say eight inches in length, and 

 the whole mass is cemented together into a very hard and often 

 compact rock by brown iron ore of a semicrystalline siliceous 

 character. The bed is also fossiliferous, in that it contains bits 

 of decayed vegetable detritus, amongst which well-preserved nuts 

 (hazel-nuts) occur. These organic remains are not petrified, but 

 only browned and blackened, just as we sometimes find Lepidostrobi, 

 ferns, etc., occurring in a peculiar decayed and carbonised condition 

 in certain beds of the Coal-measures. 



In regard to the derivation of this conglomerate and the way in 

 which it was probably formed, I may add that the nodular lumps 

 of earthy iron-ore, as well as the harder limonite-crusted masses, 

 were originally clay-ironstones, etc., of the neighbouring Coal-mea- 

 sui-es ; that the fragments of hard haematite (which are ' burnishers') 

 have been derived from the outcrop of the Permian breccias by 

 which the western margin of the exposed Leicestershire Coal-field 

 is partly overlaid [see Geol. Mag. for 1885, p. 333], and that the 

 quartz and other pebbles, etc., have come from the Bunter series, also 

 found within a mile or so of the locality of this iron-ore gravel- 

 bed. The nuts, twigs, etc., were of course buried during the 

 deposition of the gravel, but the cementing iron-ore, which has acted 

 chemically so much upon the mass (as evidenced by the staining of 

 the pebbles and the alteration of the clay iron-stones and other frag- 

 ments), I consider has been thrown down during a quiet period 

 subsequent to the deposition of the stones, etc., and was most likely 

 produced from chalybeate waters issuing from the Coal-measures 

 close by the bed of gravel ; the whole was subsequently covered over, 

 and thus consolidation resulted. 



It need scai'cely be added, that the presence of hazel-nuts in the 

 deposit proves it to be of quite recent date. 



Postscript. — The finding of a rusty iron nail of square section, 

 in lengh 2| inches, which is thickly, though irregularly, encrusted 

 with iron oxide and sandy matter, in this deposit, shows it to be of 

 quite recent date. 



I am inclined to think, from the appearance of the locality, that 

 this iron-gravel occupies what was once the upper or shallow end of 

 the bed of a mill-pond ; at all events the character of the deposit is 

 such as we might perhaps expect to find in such a situation. 



