Cu-Au vein-type mineralization in the Danyore Valley, Kohistan arc, northern Pakistan: Insights from geochemistry, geochronology, and sulfide alteration

The Kohistan terrane of northern Pakistan, one of the largest Cretaceous island-arc complexes, is well documented in terms of tectono-magmatic evolution, yet its metallogenic framework remains poorly constrained. The Danyore Valley in Gilgit-Baltistan hosts Cu-Au-bearing quartz veins associated with Mesozoic gabbro-diorite intrusions of the Ladakh-Kohistan arc. The age, petrogenesis, and ore-forming processes of this system have not previously been established. Here, we integrate field observations, petrography, whole-rock geochemistry, LA-ICP-MS zircon U-Pb geochronology, zircon and sulfide geochemistry, and S-Pb isotopic data to constrain the evolution of the host rocks and the origin of mineralization. Zircon U–Pb dating indicates Early Cretaceous crystallization ages (∼110 Ma) for the host rocks, while geochemical signatures reveal a calc-alkaline arc affinity, derived from a depleted mantle source metasomatized by slab-derived fluids and modified through fractional crystallization in a continental margin setting. The sulfide mineralization occurs in NW- and NE-trending quartz veins dominated by chalcopyrite, pyrite, and bornite with notable gold enrichment, accompanied by phyllic, propylitic, and carbonatization alteration. Sulfur and lead isotope compositions suggest mixed mantle and crustal sources, including contributions from granitoids of the Kohistan Batholith. Collectively, these results demonstrate that the Danyore Valley mineralization represents an Early Cretaceous, structurally controlled, arc-related Cu–Au vein system, thereby reducing metallogenic uncertainty within the Kohistan terrane and highlighting its exploration potential.