320. 
The limestone is generally traversed by veins of calcareous spar 
and fluor spar, frequently so arranged as to resemble the stripes in 
the skin of a zebra. It is also occasionally magnetic, on account of 
disseminated particles of magnetic iron. ‘The stratification is regu- 
lar in some places, but it generally presents great inflexions and 
disruptions, and curves of a thousand different natures. The pre- 
vailing strike of the beds is from east to west, but from the western 
base of the mountain at Castala to near the highest point in the 
Loma del Sueno and Collado de los Valientes, it is from north to 
south. The inclination of the beds varies very much both in direc- 
tion and inclination; the former being sometimes south, but often 
north, and occasionally east; and the latter differing from 15° to 
45°. The beds are for the greater part compact, but the higher 
consist of a breccia, mixed with slate-clay and clayey ochres. ‘The 
stratification in these beds is sometimes well pronounced, and at 
others less so, being of great thickness. The fragments of the calca- 
reous breccia are angular and of various sizes, and are cemented by 
carbonate of lime. 
In the ravine of Cartala, protruded masses of trap, containing 
veins of asbestos, amphibole, and porcellanite, are stated to have dis- 
located the strata; an inconsiderable vein of trap is also described 
as interposed between two beds of limestone. ‘The slate clays 
near the masses of trap, are said to be frequently of a green colour. 
At the eastern extremity of the chain, the limestone is overlaid 
by beds of gypsum, containing masses and strings or small veins of 
native sulphur. 
There is no doubt that mines in this mountain chain were worked 
by the Romans. The ore is generally found in nests or masses of 
inconsiderable size; also in veins and branches of limited extent in 
‘any constant direction, crossing each other, and forming almost 
always communications between the nests. Mr. Lambert is there- 
fore induced to consider these metallic accumulations as of contem- 
poraneous origin with the limestone. At the mine of Arnafe, on 
the western edge of the Sierra, the ore occurs between two beds cf 
limestone, having the same direction east, 20° north, and dipping 
with them 80° to the N.E. It is one foot thick, and is accompanied 
by clay. The same agreement has been found in Santa Rosa, Santa 
Catalina, Cruzados, Trinidad primero, and in all the mines situated 
upon the western declivity, looking towards Berja. 
In the Loma del Sueiio, and the interior parts of the Sierra, where 
the beds incline only 20° to 30°, but frequently exhibit great dis- 
locations, which change their position entirely, and often form 
crests, fissures, and hollows filled with argillaceous substances, are 
found the greatest masses of ore, lying between the beds, and con- 
forming to all their modifications. Fluor almost always accom- 
panies the galena. 
One level has been carried nearly 600 yards in length, from the 
bottom of a precipice of nearly equal altitude, in order to under- 
mine the rich deposits on the edge of the Loma del Sueno, but 
hitherto nothing has been met with but compact and slaty lime- 
