THE CHURCH AT HUERCAL.
The present leaseholders opened their negotiations for the purchase of the Huercal Mines on the strength of the mammoth dumps which from a number of assays made by different firms gave results varying from 5·71 per cent. to 10·40 per cent. of copper, 2·19 per cent. of nickel, and 3·13 per cent. of cobalt. It was argued that even if the mines were worked out, the dumps alone, if scientifically treated with modern machinery, would return a handsome profit. But very little exploration work was required to convince the Englishmen that so far from the property being exhausted of its mineral treasures, the bulk of the mineral had been little more than pecked at; and a more comprehensive system of development disclosed the fact that in El Monte Minado they had acquired a copper-cobalt mine of extraordinary richness. The consistent and surprising richness of the dumps in carbonates and copper pyrites made it abundantly clear that if the Romans, with their primitive methods and appliances, had regarded this ore as unprofitable for treatment, they must have found still more valuable deposits to engage their attention. There could be no other excuse for regarding five per cent. copper ore as débris. For the first time since the Roman miners left their Bonanza, the old workings were now cleared and the mystery was solved. These ancient galleries, as will be seen from the illustrations, were not driven on any systematic plan, but simply followed the lodes blindly through all their twists and curves. The idea of going boldly through the mountain and sweeping all before them does not appear to have been considered practicable by the Romans; and, doubtless, the danger of excavating in the soft country rock on a large scale had also been taken into their calculations. As the workings were freed from the rubbish that choked every drive and level, further traces of cobalt and nickel were encountered, and copper in its many beautiful forms became more abundant, and of richer quality. In the Napoleon gallery the ore was assayed to yield from 17·17 per cent. to 78·69 per cent. of copper, and at the extreme end of it was found to be in the face of a three-foot lode, in which native copper was also discovered.
THE CASTLE AND HARBOUR, AGUILAS.
As I follow Señor José Perez, the mine manager, through the old Napoleon and Esperanza galleries, it is impossible to resist the contagious enthusiasm with which he describes and exhibits the property. Certainly there is excuse on every side for their eulogiums. The copper in the lodes is very plentiful, while in the hanging-wall of the lodes important veins of pink and black cobalt are frequently to be found, and at all points where work had been done abundance of ore has been exposed. I was shown a large caverture, the roof of which is supported by a single column of ore, which had been left for that purpose by the Roman excavators. The miners who were clearing the drives at first took this circular chamber to be a break in the lode; but it is really a cavern in the walls, and roof of which nearly every variety of copper ore is to be seen. The spectacle is strikingly beautiful, and to the geologist it presents a feature of unusual interest. I have examined many caverns in mines, but this particular example, which has been christened “The Cathedral,” far exceeds in natural beauty anything of the kind that I have ever seen.
HEAPS OF COPPER ORE, HUERCAL.
A considerable amount of useful development had been accomplished by clearings and surface cuttings on both sides of the mountain, and these have been of the greatest importance in the adoption of the latest scheme for working the mine. In one clearing the outcrop had been stripped over about 1,100 feet, and by this means the copper and cobalt lode had been exposed for a distance of 70 feet, and similar work had been done on the opposite side of the hill. As the result of much anxious consideration and many discussions it was decided to undertake the opening up of the mines on a scale which, it is safe to presume, the Romans never dreamed of, viz., by removing the top of the hill to a depth of thirty feet, as one scalps an egg. The ancient workings, situated at a depth of 180 feet from the summit, having been located, and their dimensions ascertained, the over-burden, which had been found to be only 30 feet in thickness, will be removed, and from that point down to 180 feet, where the ancient galleries are situated, is a mass of copper, cobalt, and nickel ores that will be worked by the open-cutting process. A trench has been cut from the “Bárris” clearing connecting with the “Marin” clearing on the other side of the mountain, and four lines of rails have been constructed to work the ores, which are loaded up into the trucks and conveyed to the sides of the hill. No timbering is necessary, shafts and drives are done away with, and all risks to life are eliminated. The soft nature of the country rock renders the work, which in quartz would be an impossibility without the aid of dynamite, a simple pick-and-shovel business, and by this means the mountain is being gutted at the price of labour and cartage.