About 12 km north-east from the town of Analavory in Madagascar are located four unusual geysers.
There is no volcanic activity underneath Analavory that superheats underground water and forces them up as steam.
In fact, the Analavory geysers arent natural at all.
The geysers are located in an area close to some aragonite mines.
Excess water from the mines are removed by metal pipes that terminate at the bank of Mazy River.
The water is warm and rich with carbonic acid that easily dissolves large amounts of lime along its way.
Further the water goes through iron pipelines, and carbonic acid dissolves iron as well.
This is similar to opening an aggravated bottle of soda.
The rusty orange color comes from the iron.
The mounds are more than 4 meters high and will continue to grow.
Sources:Wondermodo/Earth of Fire
