NOTES AND QUERIES. 
115 
were used as baths by the nuns of the convent of Lihon. A similar excavation 
occurs near Greve de Lecq, in Jersey. 
Situated about seven niiles from Guernsey, and twelve from Jersey, lies the 
beautiful little island of Sark. This island is about three miles and a half in 
length, and one and a half in breadth. Although small, there are a great many 
objects of interest in it. It is divided into two parts, Great and Little Sark, 
connected only by a tall and narrow pass, called the Coupee. On the west side 
of Sark there lies another still smaller island, called Brechon, or " I'lsle des 
Marchands," which is divided from Sark by the Guilot stream, or channel ; this 
island is about three-fourths of a mile in length, and half a mile broad. Granite 
and syenite, as usual, form the basis or lowest rock, on which a great variety of 
the metamorphic rocks repose, forming the body of the island. The granite 
makes its appearance at the two extremities of the island ; tlien syenite foUows, 
in which on the southern side many mineral veins exist, and at a place called 
Port Gorey, in Little Sark, mines of silver were for some time worked ; but the 
amount raised was not considered sufficient to defray the expenses of the working, 
so they were after some time entirely abandoned. A great variety of minerals 
were found in these mines, amongst which were muriate, chloride, and sul-. 
phuret of silver, carbonate, sulphide, sulphuret, and pliosphate of lead, 
carbonate and sulphuret of copper, sulphuret of antimony, and antimoniferous 
galena. The beautiful mineral, ruby silver, was also found, and veins and crystals 
of carbonate of lime. Heaps of the sUver ore still remain scattered about near 
the mouths of the shafts, where good specimens can be obtained. At the time 
the mines were abandoned the amount of silver which was raised was upwards 
of twenty-eight thousand ounces, besides a great deal of copper and lead. 
At the Coupee, before mentioned, there is a vein of porcelain-clay, about 
eleven feet in thickness, which appears to have proceeded from the decomposi- 
tion of the granite. This is mostly wliite, but oxide of iron (red, purple, and 
locality are of mica-scliist, and at a place called "Le Pont du Moulin" they assume 
an interesting appearance, on account of their horizontal stratiflcation, tliis is 
particularly remarkable in three masses of rocks, called the Alterns (Les 
Antelets), near this spot. 
These singular looking masses stand out alone, some distance from the shore, 
and look like piles of masonry, or some artificial structure. Probably they were 
the buttresses of a natural arch which has been washed away by the sea. On 
approaching the northern point the original granite again makes its appearance, 
and on the eastern side of the island veins of trap, greenstone, and quartz occur. 
Porphyry too is found near Le Greve ; the quartz sometimes is found of a pink 
colour, somewhat resembling the rose or nulk quartz so abundant in Norway and 
Sweden. Pot-stone, or lapis ollaris, is found near Havre Gosslin, and is used 
by the inhabitants in making vessels for domestic use, as it can easily be cut 
with a knife. Talc, hornblende, actinolite, and chlorite are also found. 
The island of Brechon, or I'lsle des Marchands, consists chiefly of gneiss ; 
but veins of different rocks occur, and here a mineral lode was discovered and 
worked with some success ; but this also was finally abandoned. Copper was 
the principal metal found there. Another metal lode was discovered at Le Pot. 
In Little Sark, in many of the caves metallic traces are discernible : iron pyrites 
is found in some of them. 
I cannot conclude these remarks on the geology of these islands without some 
notice of the curious caverns found in many of the cliffs, called by the natives 
" creux." These are crater-shaped cavities, having generally steep rocky sides 
many parts. The rocks in this 
Saxa, vocaxit Itali, nudiis quae in fluctibus aras. — Viegil. 
