Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/392

 not. In no other places where the sandstones are present have I observed these shales, except here and at Perton ; but probably, though not exposed elsewhere, they extend for some distance in this district, and are to be looked for associated with the sandstones between the Old Red Sandstone and Upper Ludlow rocks. Owing to the very few exposures of rock hereabouts, it is exceedingly difficult to get any thing like a clear and consecutive section. Here and at Putley brickyard there is a want of conformity — the only two places I have noted this ; for, as a general rule, the "passage-beds" are conformable to the Upper Silurians. About two miles further on is the better- known quarry at Tarrington. Six to eight beds of sandstone, varying in thickness, colour, and lithological character are exposed here, divided by thin partings of yellow and grey-coloured clay, having a total thickness of about 20 feet, with a rapid dip to the north. I could detect no " olive shales" here ; and the only fossils are the usual carbonized fragments of plants, including the characteristic Lycopodites. Some of the blocks of sandstone are of large size, and no doubt form a useful building-stone. The next exposure of the sandstones, including the " olive shales," is at Perton, which I have already referred to in a short paper published in the 'Journal' of this Society* ; but as I was unable then to give a detailed section, it may be desirable to add it now in descending order.

ft. in. 1. Divided beds of sandstone in thin bands 2 0 2. Dark-coloured brownish shales 3 0 3. Yellow sandstone 1 6

4. Olive shales, brown and green, more or less indurated, but generally very brittle, sandy, and slightly micaceous, and having an irregular fracture 5 0

5. Thin-bedded sandstone 5 0 6. Olive shales, often arenacous, with a thin sandy layer at the base, similar in structure to No. 4     4 to 5

Total 16 11

I was only able to make out this section satisfactorily by the aid of a ladder. The upper sandstones thin out rapidly to the south-west, the " olive shales" rising to the surface, but too high up to be reached.

The lowest stratum (No. 6) crops out at the north-west corner of the quarry ; and, on the authority of a man who had formerly worked in it, there is a good, thick, serviceable bed of yellow sandstone underneath, though I could see no trace of it. If this should prove correct, it is probably the Downton sandstone. All the sandstones are more or less fossiliferous, and yield the usual remains of carbonized plants, and abundance of Lycopodites. The Crustacea appear to be confined to the " olive shales" (Nos. 4 & 6). I sent up all I procured to Mr. Woodward ; and he informs me that the greater number belong to Pterygotus Banksii, with the exception of a small tail and three species of Eurypterus, viz. E. pygmoeus, E. acuminatus, and E. abbreviatus. One specimen of this genus consists of a con-


 * Quart. Journ. Geol. Soc. vol. xxv. p. 235, March, 1869.