speleo-, spele-, spelaeo-, spelae-, spel-, -spelean, -spelaean

1. Mineral deposits that form in a cave after the creation of the cave itself.
2. A secondary mineral deposited in a cave by the action of water; cave formation.

These deposits are generally composed of calcium carbonate dissolved from the surrounding limestone by groundwater. Carbon dioxide carried in the water is released as the water encounters the cave air; this reduces the water's capacity to hold calcite in solution and causes the calcite to be deposited.

Such deposits may accumulate to form stalactites, stalagmites, flowstone, cave pearls, and many other formations.

Speleothem growth can be dated by the uranium series dating method and they can potentially bury earlier archaeological deposits.

Surveying methods and processing of derived cave data.

Also known as urban exploration, urbex, or UE; it is the examination of the normally unseen or off-limits parts of human civilization.

Urban exploration is also commonly referred to as infiltration, although some people consider infiltration to be more closely associated with the exploration of active or inhabited sites.

In the U.S.A., it may also be referred to as "draining" (when exploring drains) "urban spelunking", and "urban caving."

1. A hollow place in the earth, either natural or artificial; a subterraneous cavity; a cavern; a den.
2. A very large fossil bear (Ursus spelaeus) similar to the grizzly bear, but larger; common in European caves.