Page:Transactions of the Geological Society, 1st series, vol. 3.djvu/412



XIII. Some Observations on the Salt Mines of Cardona, made during a Tour in Spain, in the Summer of 1814.

By THOMAS STEWART TRAILL, M.D.

[Read November 3d, 1815.]

celebrated mines occupy the head of a small valley in the immediate vicinity of Cardona, a town in the province of Catalonia.

This valley extends about half a mile in length, from the river Cardonero to the mines, in a direction from east-south-east to west north-west. Its north-western side is bounded by a very steep and lofty ridge, the summit of which is crowned by the town and castle of Cardona. The opposite boundary is somewhat less elevated; but both sides are considerably higher than the upper surface of the fossil salt. On entering this valley, the attention is arrested by bold cliffs of a greyish white colour, which are soon discovered to consist of one vast mass of salt. The sides and bottom of the valley are composed of reddish brown clay, forming a thick bed, from which here and there large imbedded masses of rock salt project in the manner of more ordinary rocks; especially along the winding ascent which leads up to the town of Cardona. The summits of the ridges which bound the valley on each side, are formed of a yellowish grey sandstone of a coarse texture, and containing many scales of grey mica.