Mineral Exploration and Ore Genesis of the Central Tethyan Metallogenic Belt in Balochistan: A Geochemical and Geochronological Approach

Abstract

The Central Tethyan Metallogenic Belt in Balochistan, Pakistan, represents a frontier province for porphyry Cu-Au exploration within the Chagai-Raskoh double-arc system, formed through multi-stage Neotethys closure involving Late Cretaceous intra-oceanic subduction and Cenozoic continental arc magmatism. This study integrates geochemical (major/trace elements, Sr-Nd-Pb isotopes) and geochronological (U-Pb zircon, Re-Os molybdenite) data to elucidate ore genesis, emphasizing adakitic signatures, oxidized mantle sources, and crustal contamination as key fertility indicators for giant deposits like Reko Diq (2.4 Gt @ 0.41% Cu, 0.22 g/t Au) and Saindak. Magmatic evolution from juvenile tholeiitic basalts (Sinjrani Volcanic Group) to calc-alkaline andesites (Humai Formation) reflects slab melting and metasomatism, with mineralization linked to Miocene-Pliocene potassic intrusions. Hyperspectral remote sensing and geophysical surveys (aeromagnetics) enhance targeting under post-mineral cover, revealing untapped potential in the Makran forearc and Dalbandin Trough. Findings underscore the role of ridge subduction and slab tears in generating high-Sr/Y magmas, providing a predictive model for polymetallic exploration in analogous Tethyan segments.