Las Médulas () is a historic gold-mining site near the town of

Ponferrada Ponferrada () is a city of Spain, located in the autonomous community of Castile and León. Ponferrada, the second most populated municipality of the Province of León, is also the capital city of El Bierzo, the only Comarcas of Spain, ''comarca'' ...

in the

comarca A ''comarca'' (, , , ) is a traditional region or local administrative division found in Portugal, Spain, and some of their former colonies, like Brazil, Nicaragua, and Panama. The term is derived from the term ''marca'', meaning a "march, mark ...

El Bierzo El Bierzo (; or ''El Bierzu''; ) is a '' comarca'' in the province of León, Spain. Its capital is the town of Ponferrada. Other major towns are Bembibre and Villafranca del Bierzo, the historical capital. The territory of El Bierzo inclu ...

(

province of León León (, ; ; ; ) is a province of northwestern Spain in the northern part of the Region of León and in the northwestern part of the autonomous community of Castile and León. About one quarter of its population of 463,746 (2018) lives in the c ...

Castile and León Castile and León is an Autonomous communities of Spain, autonomous community in northwestern Spain. Castile and León is the largest autonomous community in Spain by area, covering 94,222 km2. It is, however, sparsely populated, with a pop ...

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

). It was the most important

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

mine, as well as the largest

open-pit Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique that extracts rock (geology), rock or minerals from the earth. Open-pit mines are used when deposits of commercially ...

gold mine, in the entire

Roman Empire The Roman Empire ruled the Mediterranean and much of Europe, Western Asia and North Africa. The Roman people, Romans conquered most of this during the Roman Republic, Republic, and it was ruled by emperors following Octavian's assumption of ...

.El parque cultural , Paisaje cultural
/ref> Las Médulas Cultural Landscape is listed by

UNESCO The United Nations Educational, Scientific and Cultural Organization (UNESCO ) is a List of specialized agencies of the United Nations, specialized agency of the United Nations (UN) with the aim of promoting world peace and International secur ...

as a

World Heritage Site World Heritage Sites are landmarks and areas with legal protection under an treaty, international treaty administered by UNESCO for having cultural, historical, or scientific significance. The sites are judged to contain "cultural and natural ...

. Advanced aerial surveys conducted in 2014 using

LIDAR Lidar (, also LIDAR, an acronym of "light detection and ranging" or "laser imaging, detection, and ranging") is a method for determining ranging, ranges by targeting an object or a surface with a laser and measuring the time for the reflected li ...

have confirmed the wide extent of the Roman-era works. The spectacular landscape of Las Médulas resulted from the (wrecking of the mountains), a Roman mining technique described by

Pliny the Elder Gaius Plinius Secundus (AD 23/24 79), known in English as Pliny the Elder ( ), was a Roman Empire, Roman author, Natural history, naturalist, and naval and army commander of the early Roman Empire, and a friend of the Roman emperor, emperor Vesp ...

in 77 AD. The technique employed was a type of

hydraulic mining Hydraulic mining is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment.Paul W. Thrush, ''A Dictionary of Mining, Mineral, and Related Terms'', US Bureau of Mines, 1968, p.560. In the placer mining of ...

which involved undermining a mountain with large quantities of water. The water was supplied by interbasin transfer. At least seven long aqueducts tapped the streams of the La Cabrera district (where the rainfall in the mountains is relatively high) at a range of altitudes. The same aqueducts were used to wash the extensive

alluvial Alluvium (, ) is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluvium is also sometimes called alluvial deposit. Alluvium is ...

gold deposits. What became the Roman province of

Hispania Tarraconensis Hispania Tarraconensis was one of three Roman provinces in Hispania. It encompassed much of the northern, eastern and central territories of modern Spain along with modern North Region, Portugal, northern Portugal. Southern Spain, the region now ...

was conquered in 25 BC by the emperor

Augustus Gaius Julius Caesar Augustus (born Gaius Octavius; 23 September 63 BC – 19 August AD 14), also known as Octavian (), was the founder of the Roman Empire, who reigned as the first Roman emperor from 27 BC until his death in A ...

. Before the Roman conquest, the indigenous inhabitants obtained gold from alluvial deposits. Large-scale production did not begin until the second half of the 1st century AD.

Mining technique

, who was a

procurator Procurator (with procuracy or procuratorate referring to the office itself) may refer to: * Procurator, one engaged in procuration, the action of taking care of, hence management, stewardship, agency * Procurator (Ancient Rome), the title of var ...

in the region in 74 AD, described in his ''

Naturalis Historia The ''Natural History'' () is a Latin work by Pliny the Elder. The largest single work to have survived from the Roman Empire to the modern day, the ''Natural History'' compiles information gleaned from other ancient authors. Despite the work' ...

'' a technique of hydraulic mining that may be based on direct observation at Las Médulas:

Gold in our part of the world...is obtained in three ways: in the detritus of rivers, .... Another method is by sinking shafts; or it is sought for in the fallen débris of mountains 'aut in ruina montium quaeritur'' ... The third method will have outdone the achievements of the Giants. By means of galleries driven for long distances the mountains are mined by the light of lamps—the spells of work are also measured by lamps, and the miners do not see daylight for many months. The name for this class of mines is ''arrugiae''; also cracks give way suddenly and crush the men who have been at work, so that it actually seems less venturesome to try to get pearls and purple-fishes out of the depth of the sea: so much more dangerous have we made the earth!

Pliny also describes the methods used to wash the ores using smaller streams on riffle tables to enable the heavy gold particles to be collected. Detailed discussion follows of the methods of underground mining, used once the

placer deposit In geology, a placer deposit or placer is an accumulation of valuable minerals formed by gravity separation from a specific source rock during sedimentary processes. The name is from the Spanish language, Spanish word ''placer'', meaning "alluviu ...

s had been exhausted and the mother lode sought and discovered. Many such deep mines have been found in the mountains around Las Médulas. Mining would start with the building of aqueducts and tanks above the mineral veins, and a method called

hushing Hushing is an ancient and historic mining method using a flood or torrent of water to reveal mineral veins. The method was applied in several ways, both in prospecting for ores, and for their exploitation. Mineral veins are often hidden bel ...

used to expose the veins under the overburden. The remains of such a system have been well studied at

Dolaucothi Gold Mines The Dolaucothi Gold Mines (; ) (), also known as the Ogofau Gold Mine, are ancient Roman surface and underground mines located in the valley of the River Cothi, near Pumsaint, Carmarthenshire, Wales. The gold mines are located within the ...

, a smaller-scale site in

South Wales South Wales ( ) is a Regions of Wales, loosely defined region of Wales bordered by England to the east and mid Wales to the north. Generally considered to include the Historic counties of Wales, historic counties of Glamorgan and Monmouthshire ( ...

. Opencast methods would be pursued by

fire-setting Fire-setting is a method of traditional mining used most commonly from prehistoric times up to the Middle Ages. Fires were set against a rock face to heat the stone, which was then doused with liquid, causing the stone to fracture by thermal s ...

, which involved building fires against the rock and quenching with water. The weakened rock could then be attacked mechanically and the debris swept away by waves of water. Only when all opencast work was uneconomical would the vein be pursued by tunneling and

stoping Stoping is the process of extracting the desired ore or other mineral from an underground mine, leaving behind an open space known as a stope. Stoping is used when the country rock is sufficiently strong not to collapse into the stope, althou ...

. Pliny also stated that 20,000 Roman pounds (6,560 kg) of gold were extracted each year. The exploitation, involving 60,000 free workers, brought 5,000,000 Roman pounds (1,640,000 kg) in 250 years.

Cultural landscape

Parts of the aqueducts are still well preserved in precipitous locations, including some rock-cut inscriptions. Research on Las Médulas had been mainly carried out by Claude Domergue (1990). Systematic archaeological studies of the area, however, have been carried out since 1988 by the research group Social Structure and Territory-Landscape Archaeology of the Spanish Council for Scientific Research ( CSIC). As a result, Las Médulas ceased to be only a gold mine with its techniques and became a

cultural landscape Cultural landscape is a term used in the fields of geography, ecology, and heritage studies, to describe a symbiosis of human activity and environment. As defined by the World Heritage Committee, it is the "cultural properties hatrepresent the c ...

in which all the implications of Roman mining were made apparent. The survey and excavations of pre-Roman and Roman settlements throughout the area allowed for new historical interpretations that greatly enriched the study of Roman mining. A positive result of these systematic studies was the inclusion of Las Médulas as a

in 1997. Since then, the management of the Cultural Park has been monitored by the Las Médulas Foundation, which includes local, regional, and national stakeholders, both public and private. Currently, Las Médulas serves as an example of good research-management-society applied to heritage.

Environmental impact

The massive scale of mining at Las Médulas and other Roman sites had considerable

environmental impact Environmental issues are disruptions in the usual function of ecosystems. Further, these issues can be caused by humans ( human impact on the environment) or they can be natural. These issues are considered serious when the ecosystem cannot reco ...

. Ice core data taken from

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

suggest that mineral

air pollution Air pollution is the presence of substances in the Atmosphere of Earth, air that are harmful to humans, other living beings or the environment. Pollutants can be Gas, gases like Ground-level ozone, ozone or nitrogen oxides or small particles li ...

peaked during the Roman period. Levels of atmospheric

lead Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...

from this period were not reached again until the

Industrial Revolution The Industrial Revolution, sometimes divided into the First Industrial Revolution and Second Industrial Revolution, was a transitional period of the global economy toward more widespread, efficient and stable manufacturing processes, succee ...

some 1,700 years later. The inclusion of Las Médulas as a World Heritage Site was controversial for similar reasons. The delegate from

Thailand Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...

opposed the designation because he considered the site "a result of human destructive activities as well as harmful to the noble cause of environmental promotion and protection."

References

External links

*
Webpage of Fundación Las Médulas, with itineraries, virtual visit and practical information
(in Spanish)
UNESCO official website

"Las Médulas, the Roman El Dorado".
and ''Article by the Leonese writer Julio Llamazares.''
Spanish site dedicated to Roman technology, especially aqueducts and mines

* [https://web.archive.org/web/20081103115616/http://www.soc.staffs.ac.uk/jdw1/costa27home.html Action COST A27: Understanding pre-industrial rural and mining landscapes (LANDMARKS) European research project, a platform for scientific dissemination of Las Médulas] {{DEFAULTSORT:Las Medulas World Heritage Sites in Spain, Medulas Roman towns and cities in Spain Gold mines in Spain Gold rushes Roman aqueducts outside Rome Roman sites in Spain Badlands Economic history of Spain El Bierzo Underground mines in Spain Geography of Castile and León Ponferrada Tourist attractions in Castile and León Archaeological sites in Castile and León

Mining technique

Cultural landscape

Environmental impact

See also

References

Further reading

External links