The differentiation of basaltic magmas to form more silica-rich magma is a fundamental
process in crustal magmatism. However, suites of volcanic rocks erupted from individual
volcanic centres rarely exhibit a compositional continuum between basalt and rhyolite.
Instead, some rock suites exhibit marked compositional gaps. The origin of such gaps has
been attributed to partial melting of the crust, the immiscibility of different magma types,
crystallization of specific mineral phases and processes occurring within magma chambers …