Picrite basalt

The olivine-rich picrite basalts that occur with the more common tholeiitic basalts of Kīlauea and other volcanoes of the Hawaiian Islands are the result of accumulation of olivine crystals either in a portion of the magma chamber or in a caldera lava lake.

The name "picrite" can also be applied to an olivine-rich alkali basalt: such picrite consists largely of phenocrysts of olivine and titanium-rich augite pyroxene with minor plagioclase set in a groundmass of augite and more sodic plagioclase and perhaps analcite and biotite.

Komatiite lavas are products of more magnesium-rich melts, and good examples exhibit the spinifex texture.

In contrast, picrites are magnesium-rich because crystals of olivine have accumulated in more normal melts by magmatic processes.

[1] Picrite basalt is found in the lavas of Mauna Kea and Mauna Loa in Hawaiʻi[3], Curaçao, in the Piton de la Fournaise[4] volcano on Réunion Island and various other oceanic island volcanoes.