Subsistence Flooding
Subsistence flooding occurs when the groundwater mixes with tailings from mining. The water then dissolves the underlying stone weakening the ground. The end result is always a massive sinkhole with an unstable rim. Anything caught on the ground when the land gives way is sucked down into the morass at the bottom.
Many times buildings have been caught in collapsing earth taking everything with it and leaving businesses ruined or people homeless. There have been occasions when subsistence flooding has occurred during the night taking sleepers to their deaths. When this happens, mourners will build a shrine for the deceased. Some bereaved have thrown themselves in the pit to forever be with their loved one(s).
Tailings must remain in the mine, preferrably in a side chamber. Those who quarry rock should work with you in the mines since both are valuable and the quarries can hold your tailings. Besides then you can go through your tailings pile to find other ores or gems you weren't originally looking for. The problem is tailing piles are likely to shift and contaminate the local watersheds, causing subsistence flooding which is a hazard to all of us. Subsitence flooding can surface anywhere not just near the mine or local communities.
Manifestation
When there is subsistence flooding the ground becomes spongy before completely liquifying and dropping away. What remains is a large and deep hole wider at the bottom than the top. The bottom third is filled with a mixture of mud and water.
Localization
The areas most effected by subsistence flooding are where there has been excessive mining or tunneling. Water fills the tunnels and over time dissolves the ground. The water mixes with chemicals and becomes an acid capable of dissolving stone. Once the tunnels are full, the liquid starts disolving the ceiling at its weakest points until the ground feels like jelly.
Comments