Potosi (Bolivia), Sep 21 (EFE) The Cerro Rico de Potosi, which towers above this southern Bolivian highland city and once bankrolled Spain’s colonial presence in the Americas, still contains copious amounts of silver despite being mined uninterruptedly for 464 years.
Bolivian engineers who study how to balance mineral extraction with the goal of preserving the mountain’s conical shape have determined that the Cerro Rico, which means “rich mountain” in Spanish, contains almost 1.22 billion tonnes of mineral wealth, most of it silver.
“There’s as much silver (still there) as has been taken out,” Corsino Morales, an engineer with Bolivia’s Geological and Technical Mining Survey, told EFE.
Though it may sound like the stuff of legend to speak of a mountain that keeps on yielding riches after nearly five centuries of non-stop exploitation, such is the case of the Cerro, hailed by writers and painters of the colonial era as a gift from God and popularly considered to be made of silver ore.
Development of the Cerro deposit began in 1545 and over the centuries millions of Indians and African slaves worked under conditions of forced labour, producing tens of thousands of tonnes silver for the Spanish Empire. Tin and zinc extracted from the mine became important in more recent times.
Currently, some 10,000 miners – mostly descendants of those initial workers – toil below ground, using dynamite to create tunnels and extracting at least 2,000 tons of mineral-laden earth per day.
Conditions remain brutal, with most of the miners dying of pneumonia in their 40s, and mine drainage takes a devastating toll on the environment, making Potosi one of the world’s most polluted cities.
The Cerro’s peak is 4,702 metres above sea level and 700 metres above Potosi, considered the world’s highest city.
Gabriel Arancibia, manager of the state-run Bolivian Mining Corporation in Potosi, spoke with EFE at the summit of the “rich mountain”.
He explained in simple terms the geological phenomenon the Cerro represents, noting that even the rock on which he was seated during the interview contains silver and other minerals.
And if one does the exercise of taking two of the mountain’s rocks and smacking them together, the sound indeed is metallic.
The Cerro’s peak is the richest part of the giant deposit, but exploitation in that zone is prohibited to prevent the mountain from being decapitated and losing its conical shape, which is visible from the city of Potosi.
Bolivian engineers have found cave-ins and fractures and recommended that preservation efforts be carried out, although they say there is no danger of the mountain collapsing due to the intense mining activity.
They say the collapse of such a mass of solid rock is only possible in the event of a major earthquake, although the mountain does have a total of 90 km of perforations and galleries, according to a recent study of the mine’s structural deterioration.
The internal perforations and intense work carried out on the surface of the Cerro have led to concern among civic leaders in Potosi and environmentalists about the risk of a collapse, despite technical evaluations to the contrary.
One voice advocating preservation work on the mountain is Ruben Ruiz, the director of the National Mint of Bolivia, located in Potosi. He noted that colonial chroniclers said in their day that the mountain’s peak was higher than 5,183 metres when silver extraction began.
In other words, based on those historical records, Cerro Rico’s height may have been reduced by 481 metres over the centuries, although other figures from the mining ministry indicate that the mountain has shrunk by just 17 centimetres since the mid-1990s.
In any case, Ruiz said Potosi’s inhabitants cannot conceive of the city without its emblematic mountain and its seemingly limitless supply of silver, whose importance for global trade during the industrial revolution was similar to that of the US dollar today.
Paradoxically, the silver that left Potosi for international markets did not substantially change the lives of the majority of the inhabitants of this region, where poverty remains a fact of life and is only slightly alleviated by the influx of visitors who flock to what has become a popular tourist attraction.
