Thermal history of the Carrara Sub-basin: insights from modelling of the NDI Carrara 1 drill hole

Abstract

NDI Carrara 1 is a 1751 m stratigraphic drill hole completed in 2020 as part of the MinEx CRC National Drilling Initiative, in collaboration with Geoscience Australia and Northern Territory Geological Survey under the Exploring for the Future program. It is the first stratigraphic test of the Carrara Sub-basin, a recently discovered depocentre in the South Nicholson region. The drill hole intersected Cambrian and Proterozoic sediments consisting of organic-rich black shales and a thick sequence of interbedded black shales and silty-sandstones with hydrocarbon shows. A comprehensive analytical program carried out by Geoscience Australia on the recovered continuous core from 283 m to total depth at 1751 m provides critical data for understanding this area. Using data from this drilling campaign, thermal history modelling was undertaken to provide an estimate of the time-temperature maxima that the sub-basin has experienced, contributing to an understanding of hydrocarbon maturity. Kerogen kinetics are used to estimate the petroleum prospectivity of the sub-basin and attempt to understand the timing and nature of hydrocarbon generation. Combined, these newly modelled data provide insights into the resource potential of this frontier Proterozoic–Paleozoic hydrocarbon province, delivering foundational data to support explorers across the eastern Northern Territory and northwest Queensland.