The Bundelkhand massif of Archean‐Palaeoproterozoic age is primarily a granite‐gneiss complex. Three distinct granitoid suites have been identified within the massif hornblende granitoids, biotite granitoids and leucogranitoids, in order of decreasing age. These granitoids were emplaced in previously deformed basement consisting of gneisses, banded iron formations and other metasediments, mafic to felsic volcanics.
The granitoids exhibit a large compositional range from quartz diorite to syenogranite and show a calc‐alkaline trend. They are metaluminous to peraluminous and have I‐type characteristics. The SiO2 content ranges from 49 to 77 wt%. Low K2O/Na2O characterizes the granitoids. The oldest hornblende granitoids have low Rb and Yb contents compared to the younger biotite granitoids and leucogranitoids. Rb/Sr values for most of the granitoids are low (< 1). K/Rb ratios range from 95 to 373 which is, in general, comparable with other calc‐alkaline suites. Y/Nb ratios of the granitoids are > 1.2 which is a characteristic feature of magmas derived from sources chemically similar to island arc or continental margin basalts.
The features mentioned above coupled with concentrations of Rb, Y, Nb, Yb, Ta and Th indicate a volcanic‐arc tectonic setting for the granitoids. It is proposed that the massif represents subduction‐related magmatism of an ocean in the southern part of the massif (an Andean plate margin).
data from the Panjal Traps of Kashmir indicate that the lava erupted in a rift tectonic setting. This is also suggested by the other features of these rocks and volcanic history of the area. The time of eruption represents the initial phase of break-up of the Indian plate from the Siberian plate. This conclusion is in good agreement with the current views on the tectonic evolution of the area.
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