Orogenic gold systems within the Proterozoic Arabian–Nubian Shield remain incompletely understood, particularly the relationships between district-scale tectonic architecture, hydrothermal fluid flow, and ore-shoot localisation. This study develops an integrated geodynamic, tectono-hydrothermal, and metallogenetic model for the Kurmuk District, western Ethiopia, based on structural analysis, petrography, hydrothermal paragenesis, 3D orebody modelling, and district-scale synthesis.
The Dish Mountain, Ashashire, and Tsenge deposits are interpreted as genetically related expressions of a single district-scale orogenic gold system that evolved during progressive D1 deformation. Gold mineralisation initiated during D1c and continued into early D1d (~565–525 Ma) during dextral transpression associated with the final stages of the East African Orogeny and Gondwanan assembly. At district scale, the Kurmuk F1 antiform provided the first-order structural architecture controlling strain localisation, hydrothermal fluid flow, and orebody development. The mineral system evolved through three progressive stages: development of a mechanically heterogeneous tectono-stratigraphic framework during D1ab; establishment of a connected D1c fold–shear network that focused hydrothermal fluids and gold deposition; and progressive degradation and compartmentalisation of this mineralising architecture during D1d.
At deposit scale, mineralisation was focused within shallow-plunging parasitic fold–shear networks along the limbs of the F1 antiform, particularly where structural connectivity coincided with rheological contrasts. Gold mineralisation is interpreted to occur within interconnected deformation–dilation volumes (Integrated Seismogenic Swarm Volumes; ISVs). Two contrasting deformation-assisted pathways are recognised: a gold concentration pathway involving episodic dilation, brecciation, and telluride-assisted gold-grain coarsening; and a gold dilution pathway in which progressive mylonitisation promoted sulphide recrystallisation, gold redistribution, and grade attenuation.
These findings define a process-based exploration methodology in which targets are ranked according to preservation of favourable mineralising processes rather than individual geological features. The resulting metallogenetic model provides a predictive basis for exploration and establishes transferable targeting criteria for analogous orogenic gold systems throughout the Western Ethiopian Shield and broader Arabian–Nubian Shield.
