Fig. 2: General and detailed photomicrographs of Unit 1 ASB basalts.
From: Basalt derived from highly refractory mantle sources during early Izu-Bonin-Mariana arc development
a Medium-grained basalt from subunit 1c (78R3 21–25), including clinopyroxene (Cpx) and plagioclase (Pl) crystals (crossed polars). b Fine-grained basalt (84R1 84–87) from subunit 1e, with small crystals of clinopyroxene and plagioclase (crossed polars). c Back-scatter electron images of spinel; darker colour within the red dash line is aluminous spinel (Sp); brighter colour outside the red dash line is symplectitic magnetite (Mt). d Transmitted light image of the same spinel shown in c, red colour is the Al-rich cores, and opaque boundaries are magnetite. e Back-scatter image of spinel, Al-rich core surrounded by magnetite-rich rim outside the red dash line.
