picritic

They are composed of either tholeiitic olivine or picritic basalt.

The amounts and types of minerals make the rocks primitive basalts-also called picritic basalts.

The tholeiitic shields tend to be wider and shallower than the picritic shields.

Examples include komatiite and picritic basalt.

Ultramafic (picritic)

Dunite may also form by the accumulation of olivine crystals on the floor of large basaltic or picritic magma chambers.

An analysis by meteoriticist Hasnaa Chennaoui Aoudjehane of Hassan II University in Casablanca determined that the meteorite is a depleted picritic shergottite similar to EETA79001A.

It is perhaps the thickest accreted section of an oceanic plateau worldwide, exposing up to 6000 m of basal sediment-sill complexes, basaltic to picritic pillow lavas, pillow breccia, and thick, massive basalt flows.