Leonard Horner

“ The prevailing rock around Droitwich is a fine-grained calcareo-argillaceous sandstone, of a brownish red colour, with occasional patches and spots which are greenish blue. At Doder Hill, where a vertical section of it is exposed, it contains beds of a greenish grey colour, and of a more indurated texture, but which do not appear to differ materially in composition from the red sandstone. These contain slender veins of crystallized gypsum, the forms of which are very distinct, where the widening of the vein has produced small cavities. I did not observe any gypsum in the red sandstone. ”

“ Every geologist must have observed that the external shape of a hill is not always a certain guide in determining the bearing of the strata that compose it, and that in many places other causes must have operated in producing the external forms which the earth now exhibits. ”

“ About a quarter of a mile further south, I found a schistose rock composed of hornblende and mica, intermixed with a small quantity of felspar, quartz, and pyrites. It occurs in large masses irregularly heaped together, and the relative position of the schistose structure in the different masses preserves no uniformity. It is traversed by granite veins, varying from one to six inches in thickness, branching in different directions, and diminishing in thickness as they ascend. ”

“ We learn, however, with tolerable certainty, that these springs are impregnated from a body of rock salt; and we obtain an additional testimony in support of the observation, that rock salt is invariably accompanied by gypsum. From the rapidity with which the brine rises to the surface, it is evident that the source of these springs must be situated in much higher ground than that in which the pits are sunk. ”

“ Vast blocks of it have fallen down, and are piled above each other and strewed along the shore; in those that are within reach of the dashing of the waves the gypsum is nearly washed out, giving them a very singular appearance. The rock is not distinctly stratified, but the thickest veins of gypsum are parallel to each other, and nearly horizontal: it contains as usual the grey patches and stripes. The principal veins of gypsum are of different thicknesses; in some places they nearly equal three feet, and the red rock between them is penetrated by smaller veins branching off in all directions ”

“ The coast between Watchet and Blue Anchor is composed of the red rock with grey patches, similar to that in the eastern part of the district, of another variety of it containing gypsum, of a blackish indurated clay traversed by gypsum, and of the lyas strata. All these appear in the cliffs and on the shore at different intervals, but the great disturbances in the stratification have thrown the whole into such confusion that I found it impossible during my stay to come to any satisfactory conclusion as to their relative positions. ”

“ The greatest proportion of the rocks are in that state which the quarries term rotten; which means, that when a block of the stone is struck with the hammer, it breaks into a number of small irregular fragments, frequently not exceeding the size of a walnut, the surfaces of which are generally covered with oxide of iron, probably arising from a partial decomposition. This is the case, not merely near the surface, but in some degree even where the rock has been quarried to a considerable depth. ”

“ In 1773 Joseph Priddey, of Droitwich, informed me that he had sunk several pits, and generally found it about 35 feet to the talc, through the stratum of talc 150 feet, under the talc a river of brine 22 inches deep, under this river a hard rock of salt. When the hole is bored through the talc, the brine bursts up with amazing violence to the surface of the ground. ”

“ The last place, where I found the rock exposed at the south end of the range, was about half a mile beyond the Holly-Bush Hill ; it was called the Ragstone Hill by some quarries whom I found at work. The rock that occurs here is different from any other I met within these hills. It is of an olive green colour, and, as far as the closeness of its texture enables me to say, is composed of felspar and mica, united by a ferruginous clay, forming nearly a homogeneous mass, and occasionally traversed by veins of calcareous spar. It occurs massive, without any signs of stratification. ”

“ In passing through the village just named, I observed in the street a small block of stone differing in appearance from any I had found previously, and upon examination I found it to be granite, a rock I had searched for before without success, and indeed this is the only place where I saw an unstratified rock in the whole district, the porphyry and greenstone which accompany the grauwacke formation in Devonshire being wholly wanting here. ”

“ Very often a slender thread cuts across a thick vein, throwing it several inches out of its regular course, affording a miniature representation of the disturbances in the great veins of mining districts. These veins do not penetrate the slate either above or below the stratum of limestone in which they are contained: but there are other veins of calcareous spar which cut through the strata, generally occasioning a dislocation, and in many instances I observed the substance of the vein penetrating the adjoining strata in minute ramifications. ”

“ In the accounts of the sinking of the other pits, the brine flows over rock-salt; but here 75 feet of gypsum intervene between the brine and the salt. As all the pits are situated within the space of a square furlong, it is not probable that so remarkable a change should take place in the relative position of the gypsum and the rock salt. ↑ In different places in the town of Droitwich, the water in the wells is brackish, while in others, that are sunk to the same depth, it is quite fresh. ”

“ The central part of the range, and nearly the whole of the eastern side consist of the different compounds of felspar, hornblende, quartz, and mica, I have already alluded to. These are irregularly heaped together in large masses, and in no part could I discover them disposed in any way that could be considered as continued stratification. In some instances, the materials of the rock are so arranged as to give it a fissile appearance, and in these cases, the slaty structure is either vertical or very highly inclined. But the masses themselves I never found to be of any great extent ”

“ A great proportion of these have the structure of sandstones, the component parts varying in size from that of mustard seed to such a degree of fineness, that the particles can with difficulty be discerned. Quartz and clay are the essential component parts of all the varieties, but in different proportions. The quartz in some instances prevails to the entire exclusion of any other ingredient, forming a granular quartz rock: it is more abundant in the aggregates of a coarse grain, clay being the chief ingredient in those of a close and fissile texture. ”

“ The whole country is so covered by vegetation, either in the form of heath and turf on the high land, or of the more luxuriant productions of the vallies, that very few opportunities occur in the interior of ascertaining the nature of the rock on which the soil rests; but the cliffs on the sea shore afford such an ample field for studying the mineralogical structure of the country, that the scattered observations in quarries, may be more strongly relied on and more easily connected. ”

“ But wherever they can be seen to any extent, they exhibit a great degree of irregularity, the different kinds of rock being found in large masses confusedly heaped together. The granite chiefly occurs in the lower part of the hill, and the veins of it, which penetrate the other rocks, become more slender as they ascend, in all those places where they can be distinctly traced. ”

“ If the geologist strictly guards himself against the influence of theory in his observations of nature, and faithfully records what he has seen, there is no danger of his checking the progress of science, however much he may indulge in the speculative views of his subject. ”

“ The limestone is similar to that found in the conglomerate at Alcombe. The lower part of the valley on the south side of Grabbist hill is chiefly meadow land, but in some places where the ground is broken, as in the road near Wotton Courtney, and in the road from Timberscombe to Minehead, I observed a red marly sandstone with grey patches containing thin strata of a small sized very compact breccia composed of fragments of a white indurated clay, united by a cement of clay mixed with calcareous matter, and here and there small cavities in it lined with calcareous spar. ”

“ Between the Worcestershire Beacon and the chasm called the Wych, the rocks, on the eastern side, are similar to those I have already mentioned, except in one instance on the top of the hill, where a rock is found composed of greenish-brown mica, intermixed with hornblende. Although mica is the chief ingredient, this rock has not the slaty structure which most micaceous rocks have, but the laminæ which are pretty large, are irregularly. grouped together, and cross each other in all directions. It is an insulated mass of very small extent. ”

“ This lyas is an argillaceous limestone of a dull earthy aspect, with a large conchoidal fracture, and generally of a light slate blue colour. It occurs in very regular strata which seldom exceed a foot in thickness, and are often not more than four inches: they are separated from each other by strata of slate clay, varying considerably in thickness. All the strata of this limestone, though externally very similar, are not of the same mineralogical composition, for they have very distinct properties. ”

“ On the summit of the North-hill, a very small portion of the rock is laid bare, and it is so much decomposed, that a gentle blow of the hammer makes it break down into very small fragments. I succeeded however in obtaining a fracture that shewed the composition of the stone, which is a mixture of hornblende and reddish felspar in very small grains, similar to that noticed § 17 as occurring on the south-east side of the End-hill, and as prevailing very generally throughout the range. ”

“ To those however who may give to it the theoretical meaning which this word implies in the Wernerian system, I must again point out the alternations of quartz rock, and of a clay slate, with beds of limestone full of organic remains. The clay slate cannot be distinguished from that of a primitive country. ”