The HSB is characterized by linear rifting with abundant tholeiitic basalts and the group showing a more evident WPB-affinity is included in this study. The HSB samples show variable enrichment of Th, Rb and Ba due to crustal contamination but the occurrence of a slab contribution is also possible. The Zr/Nb and La/Nb ratios of most primitive samples are comparable with an EMI dominated source as also high BafNb and Ba/La ratios but the effect of possible contamination hampers the interpretation of Ba related ratios. The Haveri volcanics in the TSB are considered to represent a rift stage (>I 1.91 Ga) preceding arc volcanism. There is only one sample from the Haveri formation which show Th enrichment probably due to contamination. Zr/Nb ratio is comparable with MORB but the additional occurrence of more enriched source component is proposed. Hornblende gabbros and diorites (~< 1.88 Ga) from the GFGC are divided to alkalic and sub-alkalic groups. Sub-alkalic group plutonics from the CFGC show highly variable Ba/La, Ba/Nb, and Rb/Nb ratios which is interpreted as due to an increase in Ba and Rb due to stabilization of biotite during interaction with felsic melts. The most primitive gabbro has Zr/Nb, Ba/La and Th/La ratios comparable with the HSB samples. Alkalic diorites from the CFGC are enriched in incompatible elements and also contain high P205, up to 1.2%. The Th/La ratios are very low (0.03-0.05) and lowest ratios are from samples having highest Nb/Th ratio. The increasing La/Nb ratio reflects hornblendemagnetitesphene fractionation which is consistent with the mineralogical data. The interpreted source had an Zr/Nb ratio < 10 and Th/La about 0.04 but the high level of Ba can be attributed to interaction with felsic melt and/or source characteristics. Alkalic dykes from the MB and HSB also show minor assimilation effects and evidence of Nb depletion during fractionation. The interpreted source characteristics are ThfNb ~<