Gold Mineralisation in Kappil Prospect, Malappuram District, Kerala

A preliminary appraisal of gold mineralisation at Kappil indicates its association with quartz veins traversing the Archaean metamorphic complex comprising biotite-hornblende gneiss, quartz-magnetite granulite (QMG) and amphibolite. Gold mineralisation is confined to the highly sheared and fractured quartz veins/QMG carrying stringers and rich disseminations of pyrrhotite, pyrite, chalcopyrite and arsenopyrite. The visible native gold is distributed along fracture planes in quartzose portion and also as fine disseminations in pyrrhotite, pyrite and arsenopyrite indicating its introduction along with sulphide mineralisation.

The major element geochemistry on drill core samples has indicated a tholeiitic affinity for the amphibolite and a mixed pelitic and arkosic parentage for the biotite-hornblende gneiss. Trace element studies have shown sympathetic relationship of Au with Cu.

Five lensoid gold-bearing lode zones a·re distributed along shear zones trending in a N-S direction. In the initial stages gold was syngenetically deposited with sulphide-bearing magnetite quartzite (now QMG), later, remobilisation and redistribution have caused enrichment and deposition of gold along shear zones. Post-magmatic processes are considered responsible for the localisation of gold and metal sulphides.