Document Abstract
The NNW trending tholeiitic Sonakhan mafic dyke swarm of the Northern Bastar Craton is comprised of basalt to basaltic andesite (SiO2 = 46.3 wt% to 55.3 wt%; Mg# = 37 to 70) dykes. A single basaltic dyke yielded a weighted-mean 207Pb/2°6Pb baddeleyite age of 1851.1 ± 2.6 Ma. The Sr and Nd isotopes (87Sr/s6Sr, = 0.70396 to 0.70855; ski(t) = —5.7 to +2.0) am variable which is a consequence of crustal contamination. Trace element modeling suggests the dykes were likely derived by partial melting of a spinel-bearing mantle source.