Time-Space Relationship in the Metallogenetic Domains of Rajasthan

Two metallogenetic domains are discernible in Rajasthan, a copper domain towards northeast of Ajmer and a predominantly lead-zinc domain to the southwest of Ajmer along the Aravalli-Delhi strike. The metallogenetic domains can be correlated with the tectonic zones of the Aravalli-Delhi geosynclinal system. The earlier phase of sulphide mineralisation consisting primarily of lead and zinc in the Aravallis, is associated with the eugeosyncline, characterised by the presence of turbidites and ophiolites; while the latter phase of dominantly copper mineralisation in the Delhis is in the miogeosyncline, typified by comparative shallow water deposition and preponderance of acid igneous activity of the late stage of geosynclinal evolution.

Syngenetic ore formation with possible biogenic processes has played dominant role in the lead-zinc mineralisation in the eugeosyncline. Hydrothermal activity related to post-Delhi acid intrusives has influenced the copper mineralisation in the miogeosyncline. Both the domains have borne the stresses of repeated orogeny, which have reoriented ore localisation.