Imaging the Architecture of Mineral Systems and the Pathways of Ore-forming Fluids across Mongolia with Magnetotellurics

Abstract

In the framework of a mineral system approach, a combination of components is required to develop a mineral system. This includes the whole-lithosphere architecture, which controls the transport of ore-forming fluids, and favorable tectonic and geodynamic processes, occurring at various spatial and temporal scales, that influence the genesis and evolution of ore-forming fluids (Huston et al., 2016; Groves et al., 2018; Davies et al., 2020). Knowledge of the deep structural framework can advance the understanding of the development of a mineral system and the emplacement of mineral deposits. Deep geophysical exploration carried out with this aim is increasingly important for targeting new ore deposits in unexplored and underexplored regions (Dentith et al., 2018; Dentith, 2019). We analyze data and electrical resistivity models generated from magnetotelluric measurements acquired across Mongolia, part of the Central Asian Orogenic Belt, as part of a regional array (Käufl et al., 2020; Rigaud et al., 2023a, b; Comeau et al., 2024; see Fig. 1) and focus on several metallogenic zones. These zones contain significant resources of copper and gold, as well as rare earth elements. We interpret the results, with the help of geological and geochemical data, in addition to seismic velocity data, and discuss fluid transport pathways and links to the surface expressions of mineral deposits.