La Paz: Bolivian authorities have dumped roughly 30,000 tonnes of dirt on Cerro Rico to keep the shape of the Potosi mountain, which is sinking after more than five centuries of mining for silver and other minerals.
The Cooperative Mining Services firm started the filling operation on March 23 and still has to move some 20,000 tonnes of dirt and rocks onto Cerro Rico, Spanish news agency reported citing a statement issued by the country's mining ministry.
The government wants to preserve the conical shape of Cerro Rico, designated a UNESCO World Heritage Site in 1986.
The top of the mountain, which is 4,702 metres above sea level, has been dented by a 35-metre wide and 40-metre deep sinkhole.
Cerro Rico's silver and other mineral deposits have been exploited continually since 1545 and were the main source of wealth for Spain in colonial times.
At the current pace, the filling work should be completed by April 12, the ministry said.
The dirt being used is from Pailaviri, located some nine km away, where roughly three million tonnes of the mountain's dirt have been dumped since 1952.
