West Africa was subjected to deformation and exhumation in response to Gondwana break-up. The timing and extent of these events are recorded in the thermal history of the margin. This study reports new apatite fission track (AFT) data from Palaeoproterozoic basement along the primary NE-SW structural trend of the Bole-Nangodi shear zone in northwestern Ghana. The results display bimodality in AFT age (populations of ~210-180 Ma and ~115-105 Ma) and length distributions (populations of 12.2 ± 1.6 and 13.1 ± 1.4 µm), supported by differences in apatite chemistry (U concentrations). The bimodal AFT results and associated QTQt thermal history models provide evidence for multiple cooling phases. Late Triassic – Early Jurassic cooling is interpreted to be related with thermal relaxation after the emplacement of the Central Atlantic Magmatic Province (CAMP). Early to middle Cretaceous cooling is thought to be associated with exhumation during the Cretaceous onset of rifting between West Africa and Brazil. Late Cretaceous – Cenozoic cooling can be related with exhumation of the Ivory Coast – Ghana margin and NNW-SSE shortening through western Africa. Furthermore, our data record differential exhumation of the crust with respect to the Bole-Nangodi shear zone, preserving older (CAMP) cooling ages to the south and younger (rifting) cooling ages to the north of the shear zone, respectively. This suggests that the Palaeoproterozoic BN shear zone was reactivated during the Cretaceous as a result of deformation in the Equatorial Atlantic region of Africa.

Recent development in laser-ablation Lu-Hf dating has opened a new opportunity to rapidly obtain apatite ages that are potentially more robust to isotopic resetting compared to traditional U-Pb dating. However, the robustness of the apatite Lu-Hf system has not been systematically examined. To address this knowledge gap, we conducted four case studies to determine the resistivity of the apatite Lu-Hf system compared to the zircon and apatite U-Pb system. In all cases, the apatite U-Pb system records a secondary (metamorphic or metasomatic) overprint. The apatite Lu-Hf system, however, preserves primary crystallisation ages in unfoliated granitoids at temperatures of at least ∼660 °C. Above ∼730 °C, the Lu-Hf system records isotopic resetting by volume diffusion. Hence, in our observations for apatite of ‘typical’ volumes in granitoids (∼0.01-0.03 mm 2 ), the closure temperature of the Lu-Hf system is between ∼660 and ∼730 °C, consistent with theoretical calculations. In foliated granites, the Lu-Hf system records the timing of recrystallisation, while the apatite U-Pb system tends to record younger cooling ages. We also present apatite Lu-Hf dates for lower crustal xenoliths erupted with young alkali basalts, demonstrating that the Lu-Hf system can retain a memory of primary ages when exposed to magmatic temperatures for a relatively short duration. Hence, the apatite Lu-Hf system is a new insightful addition to traditional zircon (or monazite) U-Pb dating, particularly when zircons/monazites are absent or difficult to interpret due to inheritance or when U and Pb isotopes display open system behaviour. The laser-ablation based Lu-Hf method allows campaign-style studies to be conducted at a similar rate to U-Pb studies, opening new opportunities for magmatic and metamorphic studies. Supplementary material at https://doi.org/10.6084/m9.figshare.c.6365962

The McArthur Basin of the North Australian Craton is one of the very few places on Earth where extensive hydrocarbons are preserved that were generated from Mesoproterozoic source rocks, prior to the development of extensive multicellular life. It is, however, unclear precisely when hydrocarbons from these source rocks matured, and if this occurred as a singular event or multiple phases. In this study, we present new apatite fission track data from a combination of outcrop and sub‐surface samples from the McArthur Basin to investigate the post‐depositional thermal history of the basin, and to explore the timing of hydrocarbon maturation. Apatite fission track data and thermal modelling suggest that the McArthur Basin experienced a basin‐wide reheating event contemporaneous with the eruption of the Cambrian Kalkarindji Large Igneous Province in the North and West Australian cratons, during which thick (>500 m) basaltic flows blanketed the basin surface. Reheating at ca. 510 Ma coinciding with Kalkarindji volcanism is consistent with a proposed timing of elevated hydrocarbon maturation, particularly in the Beetaloo Sub‐basin, and provides a mechanism for petroleum generation throughout the basin. Subsequent regional cooling was slow and gradual, most likely facilitated by gentle erosion (ca. 0.01–0.006 km/Ma) of overlying Georgina Basin sediments in the Devonian–Carboniferous with little structural reactivation. This model provides a framework in which hydrocarbons, sourced from Mesoproterozoic carbon‐rich rocks, may have experienced thermal maturation much later in the Cambrian. Preservation of these hydrocarbons was aided by a lack of widespread structural exhumation following this event.

Deformation, metamorphism and structural reactivation in response to evolving forces at the plate boundaries are interpreted to have occurred across much of central and eastern Australia throughout the Paleozoic-Early-Mesozoic. In the North Australian Craton (NAC; Figure 1), the far-field effects of accretionary orogenesis along eastern Gondwana are traditionally grouped together as the Ordovician-Carboniferous Alice Springs Orogeny, but are unevenly distributed across both basement terranes and overlying sedimentary basins (e.g.,

The greater McArthur Basin of the North Australian Craton is one of the very few places on Earth where extensive hydrocarbons are preserved that were generated from Mesoproterozoic source rocks, prior to the development of extensive multicellular life (e.g. Cox et al., 2022). It is, however, unclear precisely when hydrocarbons from these source rocks matured, and if this occurred as a singular event or multiple phases (e.g. Crick et al., 1988; Dutkiewicz et al., 2007). In this study we present new apatite fission track data from a combination of outcrop and sub-surface samples from the McArthur Basin (Figure 1) to investigate the post depositional thermal history of the basin, and explore the timing of potential hydrocarbon maturation.