Magnetic Susceptibility and Its Correlation With Plagioclase and Whole‐Rock Geochemistry of Neoarchean Granitoids From E‐W Corridor of Bundelkhand Craton, Central India: Implication on Granite Series and Possible Link to Mineralization

ABSTRACT Based on field relationships, magnetic susceptibility (MS), phase petrology, and whole‐rock elemental geochemistry, we deduce the redox state, granite series, and mineralization potential of Neoarchean granites ( sensu lato ) from the E‐W crustal corridor of the Bundelkhand Craton, Central India. A fine‐ to medium‐grained, equigranular granites (FMEG) compositionally similar to sanukitoids are associated with mafic microgranular enclaves, whereas the high‐K, low‐magnesian, granites (HKLMG) are coarse‐grained and contain hornblende and biotite as major hydrous ferromagnesian minerals. The oxidized A‐type granites (OAG) are medium‐grained and contain biotite as only mafic mineral. A significant variation in MS value, colour, composition, and texture has been observed for the studied granites. We used MS values between Quirtile‐1 and Quirtile‐3 to reduce the external effect. The MS values for sanukitoids range from 6.34 to 11.34 × 10 −3 SI units (Avg.‐ 8.44 × 10 −3 SI units), 1.42 to 6.16 × 10 −3 SI units (Avg.‐ 4.22 × 10 −3 SI units) for HKLMG and 0.47 to 5.22 × 10 −3 SI units (Avg.‐ 1.68 × 10 −3 SI units) for OAG. The MS values and whole‐rock geochemistry of sanukitoids indicate their crystallization at elevated oxygen fugacity ( f O 2 ; −12.33 to −14.69), buffered above FMQ + 1, typically corresponding to magnetite series granites. However, the HKLMG and OAG buffered near FMQ, representing transition between oxidizing and moderate reduced f O 2 condition, corresponding to magnetite‐ilmenite series granites. High whole‐rock Nb/Ta (> 6), and Zr/Hf (> 30) ratios and plagioclase chemistry for sanukitoids suggest that the melt was water enriched and escaped fluid‐melt interaction. These granites have the potential for Cu‐Mo mineralization. In contrast, HKLMG and OAG show evidence of crustal interaction at emplacement levels, lower Fe 2 O 3 /FeO ratios (< 0.4), low MgO (< 1 wt.%), and geochemical signatures consistent with barren to weakly fertile granites. The integrated MS‐plagioclase‐geochemical framework presented here demonstrates its effectiveness in discriminating granite redox series and assessing mineralization potential in the Precambrian cratonic terrains.