PETROGENESIS OF PAL LAHARHA GRANITIC GNEISS IN EASTERN INDIAN CRATON:EVIDENCE FROM FIELD RELATIONS AND PETROCHEMISTRY DISCUSSION

摘要

Is there any reason why the petrographic modes of the “Grey hbl-magnetite bearing granitic gneiss (GGG)”, “Pink and grey banded gneiss (PGG)”, and “Two-mica migmatitic granitoid (MMG)” (pp.4l8-420) have not been given? Although the mineralogical composition of these rocks is given, it would have been desirable to have given the modes of all the samples studied, and to have plotted them in a standard modal Q-A-P diagram. This would have enabled a comparison with the normative Q-A-P diagram (Fig.8a, p.428).