Hotspots are supplied by a magma source in the Earth's mantle called a mantle plume.

The magma source for Mammoth Mountain is distinct from both the Long Valley Caldera and the Inyo Craters.

The mechanism of enrichment has also been the topic of interest with models including partial melting, assimilation of subducted sediment or derivation from a primary magma source.

The Indo-Australian Plate is slowly moving relative to the magma source which feeds these volcanoes.

The other faults do not develop as "hotspot tracks" simply because there is no magma source nearby.

The ratios of these isotopes vary among different magma bodies, so a match indicates a shared magma source.

Sills are fed by dykes as they form from a lower magma source.

The mantle plume heated the crust from below, leading to uplift of the crust and providing a magma source for the extensive volcanism observed in the region.

These rocks reflect the composition of the volcanoes' deep magma sources, where the Earth is rich in magnesium.