A new spatially continuous basement heat flow map for NW Queensland

Abstract

A recently released open file study of the depth-to-basement and basement heat flow is presented, which covers the Queensland portion of the South Nicholson Basin and includes basins underlying the Lawn Hill Platform and Georgina Basin. The present-day basement heat flow model is derived from an analysis of basement composition, structure and history, with the crustal radiogenic and mantle heat flow assessed separately. Resulting from an integrated, iterative interpretation and analysis of a wide range of publicly available spatially continuous geophysical and geological datasets, the heat flow model reproduces faithfully sharp and high-amplitude variations of the published heat flow at small distances. Variations are replicated through the integration of interpreted basement composition and a geologically driven determination of heat production within the radiogenic crustal layer. The values of mantle heat flow based on lithosphere thickness derived from seismic tomography models are consistent with published stable mantle heat flow under terranes of similar age. The long-wavelength regional variations can be attributed to the change in the thickness of the lithosphere. Regionally, the highest values of heat flow are found where radiogenic crust is the thickest and the composition is interpreted to comprise radiogenic intrusives.