Mining in Andalucía
by Chris Chaplow
Andalucía is a region rich in minerals. There are two distinct geological zones which are divided by the current River Guadalquivir basin along its East North-East / West South-West axis.
Fifty million years ago the African plate pushed into the European plate. This caused (Andalucia's ) mountains to be forced upwards and, symetrically underneath, the earth's crust to be pushed down. A section of this crust then dropped off into the earth's liquid mantel and caused the surface crust to dip, forming the Alborán Sea and Guadalquivir Valley depressions. It also caused the rocks to twist, bringing deeply buried mineral-laden rocks to the surface.
To the north of the Guadalquivir axis, copper and pyrites extend westwards from Seville into Huelva in what is known as the "Pyrites belt". The mineral pyrite is an iron sulphide. There are deposits of mercury in Almaden, silver at Guadalcanal in the Sierra Morena, silver and copper in Rio Tinto, copper and lead north of Cordoba, and lead in Linares and La Carolina, north of Jaén.
South of the Guadalquivir axis there is lead in Sierra Almagera and Sierra Gador in Almería; as well as gold in Rodalquilar, and iron in Alquife near Granada.
On the coast there is iron in the Sierra Blanca mountain range behind Marbella and in the Sierra Bermeja behind Estepona and around Casares.
History of mining in Andalucía
In ancient times, the red pigment used in cave paintings was iron-based. By the start of the Chalcolithic period, about 3500 BC, copper was being mined, and at the Los Milares settlement in Andalucía there were buildings used specifically for metallurgical activity. It is also believed that small mining settlements existed in the Sierra Blanca and Sierra Bermeja areas.
When the Phoenicians arrived in Spain they found that silver held no esteem with the local tribes. The Phoenicians mined most of their copper in modern-day Cyprus. However, iron and copper from Spain was said to be exceedingly abundant - although there is little recorded from this period. The Phoenicians sourced tin from Cornwall, while lead was also mined.
Phoenician methods were not unlike those used today. Ore was crushed and powdered and washed. It was heated until molten in white clay crucibles. Slag (impurities) were removed and skimmed off the surface, and the metal was poured into moulds. The Phoenicians were never able to separate gold and silver.
The Romans were the first to exploit the minerals on an extensive scale. Baetica was their southern Iberian province. The bronze Aljustrel tablets found in Portugal detail their mining laws: they left lamps, hammer stones, wooden ladders and esparto grass baskets. Water drainage was their greatest achievement. Human-powered waterwheels and Archimedean screws allowed them to work to depths of 200 metres, and slaves were used for the mining.
We assume that the Carthaginians continued Roman practices.
Vandals and Goths
There is little evidence of mining by the following Vandals and Goths.
The Moors invaded from northern Africa in 712 AD and they were more interested in arts and sciences than mining. However, a number of mining towns have Moorish names: Alquife (iron), Almaden (mercury) and Mazaron (copper).
During the early Catholic period after the Reconquest most of the precious metals came from the New World: gold from Mexico, Columbia and Peru; and silver from Potosi (Bolivia). However, mercury was mined in Almaden north of Seville and transported to the New World. It was needed in for the extraction of gold.
There were no mining laws, and mining rights were handled by the church. There were a few claims at this time in Andalucía: Lorenzo Galindez de Carvajal received a warrant in 1513 from the Archbishop of Badajoz; and Juan Xelder, a Bavarian, in 1553 was given rights to various mines by the Bishop of Cordoba.
Jacob Fuggers of the Austrian banking family had loaned Charles I half a million florins to help finance his election as Holy Roman Emperor and, getting behind on his repayments, the King granted Fuggers the rights to mine Almaden. Concessions ran from 1525 to 1533, 1537 to 1550 and 1563 to 1645.
At Guadalcanal in 1555, villagers Martín Delgado and Gonzalo Delgado appear to have rediscovered and registered the mines and obtained ore from seams and outcrops. On 11 October 1555 the provincial Governor, Gaston de Peralta, Marqes de Falces, received a cedula (sealed written order) from His Majesty King Charles I saying, "I am advised that in the province, in Guadalcanal, and other places nearby, they have discovered silver mines."
The King sent Agustin de Zarate, a "counter" of the royal house, to embargo the mine. He arrived at Guadalcanal on 6 November 1555 and soon reported the presence of "more than thirty thousand ducados" (one and a half million ounces of silver). Zarate reported "such wealth that had never been seen nor heard of before in this Kingdom". Martín Delgado had disappeared but was soon arrested in Seville with a large consignment of silver. Actually Delgado gave up his mining rights to King Charles I and was indemnified with 500 ducados for "finding the premier rich mine".
The royal dilemma now was how to earn from the mines without having to first invest from the royal exchequer. The answer was to sell concessions to others and also to tax the profits. However, nobody would take on the risks of a concession without a firm mining law in place.
This was established in Spain's first mining law, "Las Ordenanzas de Felipe II of 1559", by which all mines and minerals below the ground became Crown property. The take-up of concessions was not good and in 1585 the "Nuevas Leyes y Ordenanzas de minas de Felipe II" (or the second mining law) opened it further by saying any person, national or foreign, could hold a concession.
Back in Guadalcanal, Francisco de Mendoza was sent to Guadalcanal on 25 April 1556 as Visitador. Mendoza was the son of Antonio de Mendoza, the first Virrey de Nuevo España (Governor of South America ) and had experience of mining there. He had returned to Spain on the death of his father and petitioned King Charles I, who died in January 1556. It was his son King Filipe II who sent Mendoza down to Guadalcanal as Visitador with instructions to continue searching in the area for other mines. In the summer of 1556 he did just that and made an expedition west to Aracena and from there, with a local guide, rediscovered the big one: Río Tinto.
The story of mining in Andalucía was not a happy one. There were reports from Rio Tinto and Guadalcanal about various entrepreneurs holding concessions 10 ten or 20 years and then failing. The state also tried running mines without success. Lack of skills and investment and remote locations away form transport routes were the frequently cited problems.
King Charles III established a school of mines at Almaden in 1777.
Isabel II in 1840 changed mining laws that gave more security to foreign investment and lowered the import tariffs on mining equipment.
At the same time in the UK, the 1720 Bubble Act, which was a protection against South Sea Bubble, requiring all companies to have a royal charter, was relaxed in stages up to the Registration Act of 1844 and the Limited Liability Act of 1855. This made it much easier for individuals to set up limited companies.
In 1844 a lucrative Quicksilver contract was awarded by the Spanish Government to Rothschilds to work the mercury mine at Almaden. It was controversial at the time and it did spark foreign interest in mining in Spain. This led to the Taylors and others investing successfully in lead mines in Linares and Matheson in the Río Tinto copper mines.
Gold Fever in Rodalquilar
Mining was restarted in 1864 and gold fever struck in 1880. Many small mines opened up with small groups of miners chasing seams of gold with hand tools. This gold is not found in nuggets but is encrusted into the mineral-laden rock and called ore. The gold was situated in quartz with veins of other metals such as lead and silver. After crushing the ore to a powder, a chemical process called "amalgamation" using mercury was required to extract the gold. More>
HISTORY OF RIO TINTO MINES
The Río Tinto mines, located in the north of Huelva province, are reputed to be the oldest mines in the world, with the exception of mines in Cyprus. They certainly have the most longevity of those being worked today - since before 1000BC. In the late 19th century, they were the world's leading producer of copper.
Their eight square miles have provided a major source of European copper in both ancient and modern times. Río Tinto contains the largest mass of cupriferous pyrite (one of the minerals from which copper is extracted) known to man, together with some gold, silver, sulphur and iron. The red soil that dominates the landscape is caused by the oxidation of metal-bearing rocks over many millions of years.
Río Tinto mines are part of the 230-kilometre Iberian pyrite belt, extending from Aznalcollar near Seville to Aljustrel in Portugal. Pyrite is a mineral containing a combination of sulphur with iron and copper, with a metallic lustre which lends it the name "fool's gold". At certain places this mining field showed surface signs of two other vividly-coloured copper minerals: bright green malachite and deep blue azurite. This must have attracted the curiosity of the area's prehistoric inhabitants. More>
LA CAROLINA MINING MUSUEM
This excellent modern museum explains the history of the mining industry in the areas surrounding La Carolina and other settlers' towns. It charts the history from ancient times to the mining boom of the 19th century, and will be enjoyed by anyone interested in mining and industry, especially British visitors, since - as in Río Tinto (Huelva) - British engineers were involved in setting up the mines. This museum was originally called the Museo Arqueologico de La Carolina, and reopened in December 2011 as a modern interpretation centre More>
La Joya is an old mining settlement named after the Arroyo de la Joya, some 70 kilometres north of Huelva, close to the Atlantic and the Portuguese border in the Comarca (area) of La Andavalo, west of the Sierra de Aracena. It sits in rolling countryside south of the lesser-known hill-range of the Sierra de Pelada ('bare mountains"), near the town of Cabezas Rubias ('redheads") on the HU-7104 road. More>
Minas de Cala
This almost-abandoned mining village in the north of the province of Huelva is located a few kilometres from the border with the region of Extremadura and province of Badajoz. It is dependent on the nearby village of Cala, a few kilometres away.
Minas de Cala is one of several "poblados mineros" (mining towns) around Cala; others are La Sultana and Minas de Teuler.
Minas de Cala is a ghost town and only of interest to those curious about abandoned towns and industrial architecture. There are no hotels, shops or cafés. More>
Alquife has historically been a mining village producing up to 40 per cent of the iron extracted in Spain. Although closed today due to a crisis at the beginning of the past century, these mines had been in operation since the time of the Roman Empire. More>
On 25 April 1998, the Doñana Disaster, also known as the Aznalcóllar Disaster, occurred. The mineral waste retaining wall at the Swedish-owned Los Frailes pyrite mine burst, causing the most harmful environmental and socio-economic disaster in Andalucía. Approximately four to five million cubic metres of mine tailings, containing dangerous levels of several heavy metals, quickly leaked into the River Agrio and River Guadiamar, travelling 40 kilometres. Due to the immense damage caused the regional government decided in May 1998 to finance a comprehensive, multi-disciplinary research initiative with the objective of eradicating or at least minimising all of the negative social, economic and environmental impacts. The clean-up operation took three years: almost 2,000 birds, chicks, eggs and nests were killed or destroyed, and more than 25,000 kilos of dead fish were collected in the aftermath. The concession to mine again in Aznalcóllar was awarded by the Junta de Andalucía in 2015. More>
CERRO DEL HIERRO NATURAL MONUMENT
Situated in the Sierra Norte de Sevilla Natural Park near the village of San Nicolás del Puerto is Cerro del Hierro (Iron Hill). As well as being a former Roman mining site, Cerro del Hierro is noteworthy for its limestone features, among the most outstanding in Andalucía, which include chasms and gullies. Its unique microclimate means that there are some extremely interesting plants. More>
In 1555 a silver mine called Pozo Rico outside Guadalcanal was rediscovered. It soon became one of the most important silver mines in Spain, perhaps in Europe, and it was probably named after the world's biggest, the Cerro Rico mine in Potosi (Bolivia).
The silver is found bound in minerals, in veins or seams of hydrothermal vents, which also include lead, zinc and copper. In Iberian geological terms Guadalcanal is found in the Ossa-Morena zone and the rock is of the lower Cambrico period (about 500 million years ago). More>
VILLANUEVA DEL RÍO Y MINAS
Minas de la Reunion is part of a mining basin is comprised of a huge hypogenic mass running NW to SE. Its southern edge is in contact with a more recent formation which is the base of the coal deposit. In this basin, coal sediments are broken down into three groups: base gaps, production face and ceiling conglomerates. More>
Alto Guadiato Mining District
The Belmez, Espiel, Pozoblanco and Peiiarroya-Pueblonuevo (Cordoba) mining basin yields coal- rich carbonated deposits. The mining of copper pyrite and lead-rich galena also became very important. More>
SIERRA ALMAGRERA MINING DISTRICT
Sierra Almagrera in southwest Spain is a small, four-kilometre wide mountain range running parallel to the coast for a distance of 12 kilometres with a maximum altitude of under 400 metres in the municipalities of Cuevas del Almanzora and Pulpi. It is known for its rich deposits of silver and lead. More>
SIERRA DEL AGUILON
Sierra del Aguilón has been subject to mining exploitation throughout history. Contemporary mining began in 1840, with the use of trenches and cuts into silver galena. Mining ceased in the Civil War. “Mina Rica” seemed forgotten, it resurfaced in December 1999 with the discovery of the largest mineral geode in Europe. It is open to the public. More>