562 Geological Society: — Mr. J. Lambert 



(lat. about 37° 17', long, about 15° 40') in a N.N.W. direction for 

 twelve miles. Its width is about a mile and a half, and its greatest 

 height 1400 feet. It is composed of clay-slate, resting upon mica- 

 slate, accompanied by beds of milky quartz, and crossed by numerous 

 ferruginous veins containing sulphate of barytes and gypsum. The 

 strata of the clay-slate are generallj' horizontal, but are sometimes 

 inclined from 15° to 20°, and even more, where disturbed by masses 

 of greenstone. 



The vein of the Barranco Jaroso was the first discovered, and 

 it is now of considerable richness. Its excavations extend more 

 than 200 yards in length, with every indication of the lode con- 

 tinuing. The direction of the vein is north to south, between 

 one and one and a half hours, or 15° to 22^° east of north ; and the 

 inclination is from 65° to 70° east. The breadth of the vein, where 

 it was commenced at the surface, was half a yard, but it had in- 

 creased to three yards at the depth of forty yards, the point to which 

 it had been carried in April 1840. The mineral contents of the 

 vein consist of parallel divisions of several varieties of galena, as crj'- 

 stallized, radiated with an antimonial aspect, brilliant large-grained, 

 fine steel-grained, and black, of oxide and carbonate of lead, and 

 argillaceous iron ore ; carbonate of iron and carbonate of copper 

 also occur ; and sulphates of barytes and gypsum are abundant. 



Old workings, supposed to have been conducted by the Romans, 

 occur in great numbers, principally at the mouths of the Barrancos 

 or ravines of Pinalbo del Frances and de la Torre. Quantities of mine- 

 timber, decayed iron tools and lamps of clay, have been found in 

 them ; but in no case does it appear that gunpowder was used in 

 making the excavations. Large heaps of slags and scoria are of 

 frequent occurrence ; one of the most important being situated be- 

 tween the confluence of the Almanzora and the Rambla de Muleya 

 at the foot of the little hill Cabeza de las Herrerias (Head of the 

 Forges). 



This hill, Mr. Lambert says, presents the aspect of a volcanic 

 crater, and has disturbed the tertiary deposits of the neighbourhood. 

 He states, that it is an enormous mass of oxide of iron, with a mul- 

 titude of veins of sulphate of barytes ; and that it is absolutely 

 honey-combed by old excavations in the barytes veins, the contents 

 of which, he believes, were used as a flux in smelting the argen- 

 tiferous minerals. The tertiary beds at this locality consist of clays 

 resting upon conglomerates, and are all charged with iron. They 

 are stated to contain also " feiTuglnous and jaspery dendrites," veins 

 of felspar and crystals of barytes. 



A tertiary formation extends from the foot of the Sierra Almagrera 

 to the Sierras de Filabres, de Alhamilla and Cabrera. The upper 

 part consists of an arenaceous conglomerate alternating with marls, 

 and beds of quartz and other pebbles of various sizes. The clays con- 

 tain gypsum and sands very similar to those of the vicinity of Paris ; 

 and numerous organic remains, belonging principally to the genera 

 Ostrea, Pecten, and Dentalium ; likewise corals. The formation is 

 disturbed in many parts by protruded masses of greenstone ; also 



