ultrabasic

[ uhl-truh-bey-sik ]
/ ˌʌl trəˈbeɪ sɪk /

adjective

(of rocks) containing iron and magnesium, with little or no silica.
Also ultramafic.

Origin of ultrabasic

First recorded in 1890–95; ultra- + basic

Words nearby ultrabasic

ultra, ultra filtration, ultra vires, ultra-, ultra-distance, ultrabasic, ultracentrifuge, ultraclean, ultraconservative, ultracrepidarian, ultracritical

Example sentences from the Web for ultrabasic

British Dictionary definitions for ultrabasic

ultrabasic
/ (ˌʌltrəˈbeɪsɪk) /

adjective

(of such igneous rocks as peridotite) containing less than 45 per cent silica

Scientific definitions for ultrabasic

ultrabasic
[ ŭl′trə-bā′sĭk ]

Containing magnesium and iron and only a very small amount of silica. Used of igneous rock, and often used interchangeably with ultramafic. Peridotite is an ultrabasic rock.