How thick is the Strathbogie Complex?

Abstract

The Strathbogie Complex is a large granitic body in north central Victoria. Previous detailed mapping of part of its western and southern boundary suggested that the body was relatively thin, probably less than 1 km. However, forward modelling its gravity response suggests the complex is thicker, perhaps more than 6 km in its deepest parts. The only way the measured gravity response could be modelled to fit a maximum thickness of 1.5 km is with an unrealistically low density. While not definitive, the modelling provides a warning that, where available, even excellent surface mapping should be combined with other data to obtain the most realistic subsurface geometries.