Timing and genesis of Cu–(Au) mineralization in the Khetri Copper Belt, northwestern India: constraints from in situ U–Pb ages and Sm–Nd isotopes of monazite-(Ce)

The Khetri Copper Belt (KCB) in northwestern India contains several economically important hydrothermal Cu–(Au) deposits. Orebodies in these deposits are locally rich in monazite-(Ce). In this study, in situ U–Pb ages and Sm–Nd isotopic compositions of monazite-(Ce) are used to constrain the timing of mineralization and to better understand the genesis of the Cu–(Au) deposits. Monazite-(Ce) crystals were identified in the Madhan-Kudhan and Kolihan deposits in the KCB. Most monazite-(Ce) crystals in the two deposits show close textural associations with hydrothermal minerals (biotite, chlorite, and sulfide) and have low contents of ThO2 (mostly