John MacCulloch

“ Detached masses of rock surrounded by the sea, and relieved by the broad cliffs which bound it, constitute its peculiar feature. The whole of these rocks are of grauwacké schist and grauwacké. The strata are nearly horizontal, and are occasionally intersected by veins of quartz, as is common elsewhere. It is no where of a foliated fracture producing roofing slate, but in many places breaks into pieces well adapted for square masonry. In some places where it lies near to granite it seems to undergo an alteration of texture, and to become more siliceous. ”

“ The high rocks which stretch away to sea all round Jersey seem to be of granitic formation.
The Bay of St. Ouen is a large flat sandy tract occupying the whole western side of the island, and bounded by a ridge of sienitic rock, of which species all the granite of Jersey appears to be. A few rocks of grauwacké schist are seen emerging from the sand. This coast is subject to a sandy inundation, but it does not appear to spread rapidly: no precautions are taken to prevent it. ”

“ On the southern side of the island they are intersected by veins of white, flesh-coloured, and red felspar, of various breadths. In some places the felspar veins pass into granite. Veins of quartz, and veins of a granitel consisting of quartz and felspar, also traverse it. A few veins of trap are also found intersecting it at Rocquaine, which are occasionally superseded by trap porphyry, or by the same substance containing minute grains of quartz. In this tract there are wrought two or three quarries of a black granitel, consisting of hornblende and quartz, and very hard. ”

“ Where the strata of grit cease, a vein, or an inclined stratum, of black granitel, composed of hornblende and quartz, is found; which appears to run straight, and in contact with them, in a N and S direction across the whole island, from l'Etat to Braie. This is a thick mass, but I could neither discover its dimensions, nor its points of contact with the grit. It is in some places accompanied by a fine-grained sienite of a compact nature ”

“ The whole of this porphyry has a hornstone basis, and is either red, grey, or white. Together with the felspar, it frequently contains imbedded grains of quartz. On the beach I picked up flints, and pebbles of different coloured hornstone. It is a necessary consequence of such an arrangement of rocks, that a great part of the soil of Alderney should be sandy. It is nevertheless well supplied with water, and produces good crops of grain and vegetables. Its valuable breed of cows is well known. ”

“ The clay is of a strong red colour, containing much oxide of iron, and with it so much carbonate of lime as to effervesce considerably with acids. The limestone is in some parts formed of various marine remains, in others it is uniformly granular. Through both these there are dispersed in various places deposits of copper ore in small quantities. These consist of carbonate of copper, diffused through the earthy matters; and of crystallized masses of the same substance; and, more rarely, there are found lumps of red oxide mixed with particles of grey ore and native copper. ”

“ Lapis ollaris is also found there, as well as in the land lying above the cliffs, from which I guess that this vein extends across the island. It is applied by the natives to economical uses.
A very large wall of a redish granite, the end of a vein from which the schistose strata have been washed, stands far out on the shore, forming a natural arch. Where the arch is formed, a softer crow fissure seems to have existed from which the looser materials have been washed away. ”

“ These veins wherever I saw them seemed to consist of granite, of which the felspar was commonly of a brick red colour. The sienite itself is in general white, consisting of variable mixtures of quartz, felspar, and hornblende, and varying therefore in colour. Most commonly the felspar is predominant.
In the rocks of Mont Mado the felspar is particularly abundant, and is of a flesh colour, constituting a very beautiful variety, which is also susceptible of a fine polish. ”

“ Where its passage is narrowed, and diverted by the land, it forms those currents of which the variety and intricacy is so great, and of which the rapidity is such, as in some places to amount (it is said) to six miles in an hour. ”

“ More rarely there are found in it veins of brick red and bright green felspar, and pebbles of the same substance, or with hornblende imbedded, are found on the beach, as well as coarse agates passing into quartz and hornstone.
Proceeding from the Castle southwards, gneiss is found to constitute the cliffs on the eastern side, often in a state of decomposition, and covered with a great depth of debris. These strata, which extend all along the south coast to Rocquaine Bay, seem to tend from NE to SW; and have various inclinations, but most generally 10° or 15°, dipping to the south. ”

“ At the western point in particular, where it is exposed to the undiminished force of the wind and the sea, it has undergone considerable changes, and many detached rocks of rude forms are the consequence. ”

“ Indeed, the shores in general being high, small changes of level are more likely to escape notice; and the rocks being of a firm constitution, and belonging to a country without rivers, and almost without ice, escape some of the ordinary causes of decay.
ALDERNEY.
THE approach to this island is somewhat dangerous, from the rapidity and perplexity of the tides, and the number of the rocks which surround it. ”

“ These are accompanied by veins of mica and felspar in various states of decomposition, apparently from the failure of the mica, and by veins of chlorite containing here and there pyrites, together with talc and quartz, and calcaceous schistus, and a mixture of greenish steatite, felspar, and quartz. The rocks here also are of trap formation, and the beach is covered with jaspideous pebbles as at Havre Gosselin.
Such is Grande Havre, and the number of the soft veins here existing may serve to account for the great waste the land has undergone. The Coupée is becoming daily lower to the eye. ”

“ Its extreme breadth is not more than a mile and a half, and its average breadth not quite a mile. In one part, it is not many yards wide, being nearly divided into two portions, connected only by a high and narrow ridge. ”