speleothem

English

From Ancient Greek σπήλαιον (spḗlaion, “cave”) + θέμα (théma, “what is laid down”).

speleothem (plural speleothems)

(geology) Any secondary mineral, deposited in a natural cave by the action of water.
- 2021 January 13, Becky Ferreira, “Pig Painting May Be World’s Oldest Cave Art Yet, Archaeologists Say”, in The New York Times‎^[1], →ISSN:
  But it is possible that the painting itself might be thousands of years older because the technique only assesses the age of a mineral deposit, speleothem, that formed on the cave walls.

secondary mineral, deposited in a cave by the action of water