Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/29



Galena is found together with pyrites in the nodules of clay-ironstone, that are imbedded in the shale: as at Montagu main, at the depth of 40 fathoms.

Iron pyrites is found in great abundance crystallized and disseminated in the beds both of coal and of shale: it is sold to the manufacturers of green vitriol.

Azure iron ore is not uncommon in the potters' clay at Elswick, and in other brick fields.

Calcareous spar is common, either blended with the coal or in the form of stalagmites.

The Organic remains found in the coal measures are,

Impressions of plants resembling those of the genera fontinalis and equisetum, except that the latter are destitute of the jointed stem of the true equiseta. In shale.

A fern, like polypodium filix mas, (Parkinson, vol. i. tab. 4. fig. 7.) Impressions of plants, (vide Parkinson, vol. i. tab. 3. fig. 6, 7.) In shale.

A fern, like blechnum boreale, (Parkinson, tab. 4. fig. 1, 2. and Sowerby, tab. 296.) and another like osmunda regalis; from Kenton colliery, and from the shale contiguous to the Coley hill dyke. In nodules of clay iron-stone.

Impressions of cones, (Parkinson, vol. i. tab. 9. fig, 1.) from Urpeth Dean, Durham. In nodules of clay ironstone.

Obscure impressions of a fern, from Murton colliery. In nodules of clay ironstone.

Large flattened lumps of iron pyrites, bearing the form of the stem and the impression of the bark of a plant resembling an euphorbia; called by the miners petrified salmon. From the floor of several collieries.