Page:The South Staffordshire Coalfield - Joseph Beete Jukes - 1859.djvu/22

6 Red and Mottled sandstone. West and north of Hagley the same strata, repeated by faults, run from the neighbourhood of Church Hill and Heathside to Wolverhampton and the country west of Trysull, and beyond Wolverhampton they strike northward to Cannock in a band on an average about a mile wide. North of Cannock they widen out, and form almost all Cannock Chase between Rugeley and Bednall. On the east the chief area lies between Harborne, Sutton Park and the Brown Hills, where the New red sandstone is faulted against the Coal-measures.

"The conglomerate is generally more or less incoherent, but occasionally it is cemented into hardish rock by the presence of carbonate of lime. In general, however, it still so completely retains its original character of gravel, that it may be dug out with the pickaxe and shovel, and is used for gravel pits. Occasionally it consists chiefly of sand, with only a few scattered quartz pebbles, as, for instance, in the small patch between Northfield and Frankly.

"The pebbles found in these conglomerates consist chiefly of brown and liver-coloured quartz rock, well water-worn and rounded. These were for long considered to' have been derived from the waste of the altered Caradoc sandstone of the Lickey Hills; but when we consider that the same conglomeritic formation, only interrupted by faults, extends all the way from the neighbourhood of Stourport to Lancashire and Nottinghamshire (wherever it has been mapped by the Geological Survey', it is evident that the pebbles have been derived from some other source, the locality of which is unknown. Besides these, there are other occasional pebbles of white quartz, coal-measure sandstone, or millstone grit (stigmaria markings being sometimes discernible in them), chert containing casts of crinoidal stems from the mountain limestone, dull red sandstone, traps, agates more or less decomposed, altered slate, and jasper."

The Drift gravel that more or less covers the country is in a great measure derived from the waste of this conglomerate, and without practice it is at first, sometimes, very difficult to distinguish between these ancient gravels of the New red sandstone period and the other gravels that belong to the much more modern period in which "the Drift" was formed.

In examining a gravel pit for this purpose, the first thing to look for is a chalk flint. True chalk flints, with chalk fossils, may be in some places pretty abundantly found in the gravels of Staffordshire, as sometimes also oolitic and liassic fossils Where these occur they are, of course, conclusive evidence against the gravel being of the New red sandstone period. Very often, however, there are large deposits of gravel belonging to the Pleistocene or some of the more recent periods, in which no fragments of rock are found that can be identified with anything newer than the Coal-measures. Still, even these may, after a little practice, be