Geochemical Assessment of Mansehra Granite and Associated Pegmatite Veins, Mansehra, Khyber Pakhtunkhwa, Pakistan

Abstract

The Mansehra Granite of the Lesser Himalaya, northern Pakistan, represents a peraluminous S-type granitoid emplaced during Cambro-Ordovician crustal magmatism and is spatially associated with pegmatite veins formed during late-stage magmatic evolution. Despite its well-established petrogenetic framework, the wholerock geochemistry and distribution of critical and associated trace elements within the granite-pegmatite system have not been systematically evaluated. This study assesses the geochemical composition and critical mineral potential of the Mansehra Granite and associated pegmatite veins using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Twenty representative samples, comprising fourteen granite (MG-1 to MG-12) and six pegmatite samples (P-1 to P-6), were collected from Mansehra area. The samples were prepared using aqua regia digestion, and analyzed for major, trace, critical, and rare earth elements. The results are interpreted as aqua-regia extractable concentrations rather than total-rock abundances because aqua regia does not completely dissolve refractory silicate minerals and resistant accessory phases. The results indicate that critical-element enrichment is heterogeneous and primarily concentrated within pegmatites (P-4 to P-6). Pegmatite samples exhibit comparatively higher concentrations of Li, Be, Nb, Ge, Sn, W, Sb, U, and rare earth elements than the host granite. Correlation patterns and normalized geochemical signatures further indicate that accessory mineral fractionation and incompatible-element concentration exerted the primary control on trace-element distribution. Although several pegmatite samples display localized enrichment relative to the host granite, the analytical dataset does not demonstrate the presence of an economically viable rare-metal deposit, and the inferred occurrence of accessory minerals is based solely on geochemical signatures rather than direct mineralogical evidence. Future investigations integrating petrography, scanning electron microscopy (SEM), electron probe microanalysis (EPMA), or laser ablation ICP-MS (LA-ICP-MS) are recommended to verify the mineral hosts of critical elements and further constrain the metallogenic potential of the Mansehra Granite and its associated pegmatite veins