East Australia hotspot

The hotspot is thought to be explosive because basaltic magma interacts with groundwater in aquifers below the surface producing violent phreatomagmatic eruptions.

On the basis of the long duration of volcanic activity, its vast lateral extent, geochemistry of lavas, and seismic data, it has been proposed that the region is underlain by one or more deep mantle plumes which have forced magma up through points of weakness in the Indo-Australian Plate as it has moved northward over the source.

[2][3][4][5] The lack of clear age progression across the province and the orientation of the NVP, which is orthogonal to plate motion, are inconsistent with a single plume model.

This is now interpreted as the Crosgove hotspot and has been extended southward to the Macedon-Trentham central volcano and the Newer Volcanics Province lava field in Victoria.

[1][6] Another view is that extension from stresses brought about by changes in plate boundary configurations has caused severe lithospheric thinning resulting in decompression melting of the asthenosphere.