Speleothems - Frostwork
Delicate needle-like growths of calcite or a related mineral, aragonite, are called frostwork. In places the frostwork may grow on top of cave popcorn or boxwork. The origin of frostwork is controversial. In Wind Cave, it seems to concentrate in passages with above average airflow where, it is thought, evaporation plays a role in its formation.
Did You Know?
Wind Cave is the first cave in the world to be designated as a national park. That occurred on January 9, 1903.