Talk:gabbro
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Latest comment: 13 years ago by DCDuring in topic USBM def
USBM def
[edit]A group of dark-colored, basic intrusive igneous rocks composed principally of basic plagioclase (commonly labradorite or bytownite) and clinopyroxene (augite), with or without olivine and orthopyroxene; also, any member of that group. It is the approximate intrusive equivalent of basalt. Apatite and magnetite or ilmenite are common accessory minerals. AGI DCDuring TALK 21:19, 19 October 2011 (UTC)