Andesitic

Part of speech: adjective

Definitions

1. Relating to a type of volcanic rock characterized by intermediate silica content ; pertaining to material or processes involving such volcanic formations
2. Describing rocks or magmas with a chemical composition between basaltic and rhyolitic types ; affiliated with volcanic activity producing these intermediate materials
3. Associated with geological formations or lavas containing moderate levels of silica and minerals ; referring to features or processes involving such volcanic substances

Etymology: Andesite takes its name from the Andes, the mountain range along South America's western edge, where geologists first studied rocks of this kind. The Andes themselves carry a Quechua name, and the Spanish and English forms followed the same path. The rock name was coined in the nineteenth century as a geological term, so the story is less about ancient usage and more about a mountain range giving its name to a type of stone. The adjective "andesitic" is simply andesite plus the English suffix "-ic," which comes from Latin "-icus" and passed through Old French into Middle English. That suffix is one of the most common ways English turns a noun into a describing word, as in "basaltic" or "granitic."

Synonyms: intermediate volcanic rock