As a result, the water that reaches the soluble rock is acidic.

BBC: Who, What, Why: How are sinkholes formed?

Florida lies on bedrock made of limestone or other carbonate rock that can be eaten away by acidic groundwater, forming voids that collapse when the rock can no longer support the weight of what's above it.

CNN: Sinkhole eating family out of house and home

The state lies on bedrock made of limestone or other carbonate rock that can be eaten away by acidic groundwater, forming voids that collapse when the rock can no longer support the weight of what's above it.

CNN: Home of Florida man devoured by sinkhole to be demolished

The acidic water causes the erosion of the soluble rock layers beneath the surface - eventually creating cavernous spaces.

BBC: Who, What, Why: How are sinkholes formed?

Besides the unsightly effects that many mines have on the landscape, they usually churn out vast quantities of toxic waste in the form of acidic drainage-water and tailings the fine particles of rock produced when ore is ground down to release the minerals it contains.

ECONOMIST: Mine pollution

Scientists have found creatures thriving in places that would poison or cook most life on earth--deep inside rock, under the ocean or in hot springs, places that are extremely salty, or acidic, or bathed in radiation or heavy metals.

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