Metallogenic environment for lithium mineralisation in bauxite from Salal-Haimna area, Reasi, North West Himalaya of Jammu-Kashmir, India

The Salal-Haimna area in the northwestern Himalaya (Jammu and Kashmir) hosts India’s first reported occurrence of sedimentary-type lithium-bearing bauxite, assigned to the Cretaceous–Eocene age. The bauxite overlies the Jangalgali Formation, which consists of chert–quartzite breccia resting unconformably on the Proterozoic Sirban Limestone. Although previously evaluated as a medium-grade lithium prospect with an average lithium concentration of 583 ppm (maximum 2847 ppm), the genetic framework of lithium mineralisation had remained poorly understood. The present study aims to determine the source and mechanism of lithium enrichment. Geological traverses revealed the presence of tuffite interbedded with quartzite and chert breccia. X-ray diffraction (XRD) analysis indicates that the bauxite is mineralogically composed of kaolinite, illite, and diaspore, with minor boehmite, montmorillonite, and chlorite. Lithium concentrations are notably higher in the clay-rich matrix (503 ppm) than in pisolites (325 ppm), identifying the matrix as the primary lithium host. Laser Ablation ICP-MS analyses confirm kaolinite as the dominant lithium-bearing phase. Petrographic and SEM studies of the tuffite and claystone reveal volcanic features such as glass shards, vitric fragments, and Pele’s hair within a fine-grained groundmass of clay and quartz, suggesting a pyroclastic, acidic volcanic origin. The quartz grains are amoeboid shaped with embayed margins and fuzzy irregular outline. The study establishes that these altered volcanic rocks are the source of lithium, which was mobilised through weathering and subsequently adsorbed by clay minerals within the bauxite. The lithium enrichment in the Salal-Haimna bauxite is the result of eluviation from volcanic precursors and secondary concentration within clay-rich horizons. This study offers new insights for critical mineral exploration in lateritic bauxites.