Imprints of tectonics and magmatism in the south eastern part of the Indian shield: satellite image interpretation

The interface between the Dharwar craton and the southern part of the Eastern Ghats Belt, described here as the Terrane Boundary Shear Zone, is geologically a complex terrane. The zone also hosts many mafic-ultramafic and alkaline plutonic complexes and a recently reported Kanigiri ophiolite melange. The zone has also been subjected to complex geological processes such as rifting, subduction, accretion and collision between 2.0 Ga and 0.5 Ga. Multi-scale image interpretations has been carried out to identify major structural/tectonic elements as well as internal magmatic fabric trends of plutonic bodies, followed by detailed geological traverses and structural mapping. The results demonstrate that digitally processed satellite images are much more efficient than the normal satellite images in terms of structural and tectonic interpretations. The study also reveals new mapping results including several dominantly NE-SW, NW-SE and WNW-ESE/ENE-WSW trending mega- and major-lineaments, consistent with field observations. An attempt is made to correlate genetic and spatial relationship of lineaments with regional tectonics and magmatism.