The Newer Volcanics Province of southeastern Australia: a new classification scheme and distribution map for eruption centres

A new volcanic distribution map of the 4.5 Ma–5000 B.P. continental intraplate Newer Volcanics Province in southeastern Australia has been produced in order to document >704 eruption points from >416 volcanic centres. Volcanic centres were classified as either simple or complex, with simple centres featuring few eruption points and simple morphologies, while complex centres have multiple eruption points and complex morphologies. Centres were further characterised according to the nature of their deposits. Simple volcanoes take the form of lava shields, scoria cones, maars, ash cones and domes, and unknown eruption types. Complex centres may feature exclusively magmatic eruption products such as lava and scoria, and are therefore classified as magmatic volcanic complexes; maar volcanic complexes feature exclusively phreatomagmatic eruption products and have erupted under the influence of external water, while maar–cone volcanic complexes feature both magmatic and phreatomagmatic eruption products. Approximately half of the eruption points in the Newer Volcanics Province are associated with complex volcanic centres. The minimum area of the Newer Volcanic Province was calculated to be >19 000 km2, which may be a great underestimation, and it is estimated that the province has an eruption frequency of 1:10 800 yrs. This research has highlighted a need for further research into the Newer Volcanics Province, as many of the apparently ‘simple’ volcanic centres are likely to be more complex in nature. A spreadsheet database has been made freely available to download for research purposes, along with shapefiles for ArcGIS and kml files for Google Earth.