Thermal conductivity measurements were carried out on over 400 samples from Tertiary and Cretaceous sediments and Jurassic basalts during Ocean Drilling Program Leg 123 in the Argo Abyssal Plain, North West Australia. Ship-board physical property measurements were obtained from cores over the same intervals, and petrophysical wireline logs were run. New algorithms are demonstrated relating thermal conductivity to matrix grain type and porosity, derived only from wireline log data. Comparison with heat flows calculated using high-resolution temperature measurements at Site 765 suggest that thermal conductivities predicted from wireline logs can be used to estimate heat flow. This implies that existing exploration and production wells in which high resolution temperature measurements and thermal conductivities have not been measured could still be used to prepare regional maps of heat flow variation.