Fig. 3: Petrographic evidence for heterogeneous liquids and multi-level magma storage.
From: Cryptic evolved melts beneath monotonous basaltic shield volcanoes in the Galápagos Archipelago
a Quantitative Evaluation of Minerals by SCANing electron microscopy (QEMSCAN) phase map and b Ca map of a glomerocryst in a 2015 Wolf lava sample. The values in (b) show the An# of plagioclase zones. c−e False colour backscattered electron (BSE) images of quartz and clinopyroxene crystals in tephra samples from the 2015 Wolf eruption (d and e are adapted from Stock et al.19). The values in (d) and (e) show the Mg#cpx of clinopyroxene zones. f, g False colour BSE images of nodule samples from the 1968 Fernandina eruption, showing the phaneritic texture, a miarolitic cavity and evidence of hydrothermal alteration. An# and Mg#cpx values in black and grey show averages from crystal cores and rims, respectively. Ol – olivine, Cpx – clinopyroxene, Pl – plagioclase, Qtz – quartz, Gl – glass, Ilm – ilmenite, Py – pyrite, MC – miarolitic cavity.
