Archaean komatiites from the older schist belt of Kalyadi in western Dharwar Craton, Karnataka
Subba Rao, D.V.; Naqvi, S.M.
Journal of the Geological Society of India 53(3): 347-354
ISSN/ISBN: 0016-7622 Accession: 030165212
The cluster of enclaves at Kalyadi, Hassan district includes ultramafic-mafic metavolcanic rocks and minor metasedimentary rocks such as chert, cherty quartzite and pelite. Occurrence of pillow and vesicular structures in the ultramafic rocks is being reported for the first time from this area. The average composition of the ultramafic rocks is: SiO (sub 2) 46.05%, TiO (sub 2) 0.18%, MgO 31.81%, K (sub 2) O 0.15%, Cr 3409 ppm and Ni 1610 ppm with a CaO/Al (sub 2) O (sub 3) ratio close to 1. The composition, relict igneous structures and metasedimentary rock association are suggestive of a komatiitic affinity for these rocks, which possibly accumulated under subaqueous conditions.