Geophysical and petrologic properties of the crust/mantle boundary region, eastern Australia: relevance to the Eromanga-Brisbane Transect

Petrologic information derived from xenoliths in basaltic rocks from eastern Australia has been used to construct a stratigraphic section of the lower crust and upper mantle beneath the basaltic provinces of eastern Australia. This information is combined with the seismic, gravity and magnetic data available for the Eromanga Transect, as well as MAGSAT and heat flow data, to interpret the nature and evolution of the lower crust and crust-mantle boundary across the Eromanga Transect profile. It is suggested that the change in style, orientation and depth of reflectors beneath the western part of the Roma Shelf marks the boundary between older, more silicic deep-seated sequences to the west and a more mafic, younger component to the east. -from Authors