Inter-cratonic geochronological and geochemical correlations of the Derim Derim-Galiwinku/Yanliao reconstructed Large Igneous Province across the North Australian and North China cratons

Abstract

Large igneous provinces (LIPs) are often used as a powerful tool for constraining continental reconstructions, due to their potential to correlate radiometric emplacement ages across scattered fragments of once continuous igneous bodies, and establish the presence of coeval magmatic suites. Mesoproterozoic magmatism in northern Australia and north China has been suggested to be the dispersed fragments of a once contiguous LIP. Here we present new geochronology and geochemical data from the under-resolved northern Australian fragments of this province (the Derim Derim and Galiwinku suites), and review existing data on related Mesoproterozoic mafic sills in the North Australian Craton and the North China Craton. We propose an updated framework for shared magmatic genesis and cratonic proximity during magmatic emplacement. Apatite geochronology has been applied to date dolerite intrusions, using cogenetic minerals to constrain the initial common-Pb constraints of the dolerite samples which provides a significant advantage for dating mafic rocks. The ages of samples collected throughout the extent of the mafic magmatic province in northern Australia and north China supports coincident ca. 1330–1295 Ma magmatism across both regions, while geochemical evidence indicates a mantle plume derived melt as the probable source for both suites. Coeval intrusion of geochemically analogous sills within temporally and stratigraphically comparable sedimentary basins is supportive of plume activity proximal to a once continuous sedimentary system that covered much of the North Australian Craton and North China Craton, which supports a close connection between the cratons within the supercontinent Nuna in the Mesoproterozoic.