speleothem
noun
- a structure formed in a cave by the deposition of minerals from water, e.g., a stalactite or stalagmite.
Wiktionary
Pronunciation: /ˈspiːliəˌθɛm/ / /ˈspiːlioʊˌθɛm/
noun
Etymology: From Ancient Greek σπήλαιον (spḗlaion, “cave”) + θέμα (théma, “what is laid down”).
- Any secondary mineral, deposited in a natural cave by the action of water. Includes formations such as stalactites, stalagmites, flowstones, and helictites.
“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.”