ultramafic

[uhl-truh-maf-ik]

adjective Geology.

ultrabasic.

Origin of ultramafic

First recorded in 1940–45; ultra- + mafic

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

ultramafic in Science

ultramafic

[ŭl′trə-măf′ĭk]

Containing mainly mafic minerals. Used of igneous rocks and often used interchangeably with ultrabasic. Dunite is an ultramafic rock.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.