Peruvian ice cap harbors pollutants tracing conquistadors’ silver slave mines

Peruvian ice cap harbors pollutants tracing conquistadors’ silver slave mines
Reuters


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The north dome of the Quelccaya Ice Cap in Peru is seen in this handout photo from Ohio State University taken in 2003. | REUTERS
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WASHINGTON – After vanquishing the Inca Empire with superior weapons and a touch of treachery, the Spanish conquistadors sought to satisfy their lust for riches by forcing multitudes of native people to toil in silver mines in dire conditions that claimed many lives.

Scientists on Monday described evidence of this bitter chapter of South American history preserved deep in an ice cap in the Peruvian Andes in the form of residue from the relentless clouds of metallic dust spewed from the mines starting in the 16th century.

The mountaintop mines of Potosi in Bolivia were the world’s richest silver source.

While the Incas had long extracted silver, a new processing method introduced by the Spanish in 1572 greatly increased production even as it belched lead dust and other pollutants into the atmosphere. The pollution blew over the entire region, including the Quelccaya Ice Cap, some 500 miles (800 km) northwest in southern Peru.

The Spanish refining process involved pulverizing silver ore, containing both lead and silver, into powder, which sent metallic dust into the atmosphere. The powder was mixed with mercury. The silver was separated by heating the mixture to allow the mercury to evaporate.

More:
http://www.japantimes.co.jp/news/2015/02/11/world/peruvian-ice-cap-harbors-pollutants-tracing-conquistadors-silver-slave-mines/#.VOJ25Gc5Cbw