Ultrabasic

Part of speech: adjective

Definitions

1. Pertaining to igneous rocks that have a very low content of silica and are rich in iron and magnesium
2. Describing rocks formed from magma that contain minimal silica minerals and abundant ferromagnesian components
3. Relating to geological formations characterized by an extremely reduced proportion of silica compared to other elements

Etymology: "Ultrabasic" is a modern scientific coinage, built by bolting the prefix "ultra-" onto "basic." The "basic" half traces back to ancient Greek "basis," meaning a step, a base, or a foundation, which passed through Latin "basis" and Old French "base" before reaching Middle English as "base." Its chemical sense comes from the older idea that certain oxides behaved like bases, reacting with acids to form salts, and "basic" was adopted into English with that meaning in the 19th century. The "ultra-" half comes from Latin "ultra," meaning "beyond" or "on the far side of," the same root that gives "ultramarine" and "ultraviolet." In geology, "ultrabasic" describes igneous rocks with very low silica content, so the prefix signals that these rocks lie beyond the already silica-poor basic rocks on the scale.

Synonyms: extremely basic, highly basic

Antonyms: acidic, alkaline