Ring-shape and linear gold mining districts of zimbabwe: estimation of residual gold resources

Abstract

Background. Despite the long history of exploitation and study of Zimbabwe’s geological potential, the ranks of gold ore formations at the level of regions and fields remain unclear. Assessment of the residual primary gold deposits in Zimbabwe appears an important research direction.Aim. Identification of ring-shaped and linear ore districts confined to greenstone belts corresponding in configuration within the gold province of the Zimbabwe craton.Materials and methods. The main method for analyzing gold ore deposits was ore formation analysis. To analyze the residual gold resources in the regions of Zimbabwe, the Zipf-Lotke-Bradford rule was applied according to the ratio of an outstanding rare event in the form of a large deposit, rather rare events in the form of medium-sized deposits, and fairly rare events in the form of small ore objects in a certain ore region.Results. A hypothesis is proposed for the formation of ring-shaped belts as ore-bearing volcano-tectonic structures of the central type. Within the gold province of the Zimbabwe craton, ore districts of ring-shaped and linear shape, confined to greenstone belts corresponding in configuration, are identified for the first time. It is shown that the localization of deposits in ore regions is due to a combination of the following criteria: ancient faults, arc fragments of greenstone belts, and the development of post-tectonic multiphase granitoid magmatism. A ranking of deposits was carried out in the ore districts of Darwin, Shamva, Midlands, Bulawayo, Gwanda, Busha Mwezi - Fort Victoria, Shashe - Ozi-Umatli, and Sinoia. Five gold mining areas corresponding to volcano-plutonic ring-shape structures and three linear areas were identified. Productivity is predicted to be highest in the Midlands, Bulawayo, and Shamva ring-shape regions. An assessment of the residual gold resources of each of the selected areas is given. The feasibility of detailing important forecast criteria — Late Archean linear and arc faults and post-tectonic granitoids — with the development of additional criteria for further metallogenic zoning and localization of promising areas is established.Conclusions. The presented data serve as the basis for assessing the prospects of industrially important primary gold deposits in Zimbabwe and carrying out their forecast in the identified gold mining areas.