• G. Nagaraju
• Ch. Karunakar
• M. Srinivas

The Eastern Dharwar Craton (EDC) contains several Late Neoarchean to Paleoproterozoic syenites, whose origin is ambiguous. This work presents a petrological analysis of the Danduvaripalle syenites (DVS), located at the western boundary of the Paleo-Mesoproterozoic Cuddapah Basin in the Eastern Dharwar Craton (EDC). The syenites are petrographically constituted of K-feldspar perthite, quartz, and plagioclase, with hornblende and biotite as the mafic minerals. The field observations, concise microscopic analyses of Danduvaripalle syenites, and comprehensive microstructural examinations reveal significant variance from primary igneous magmatic textures to deformed microstructures. These granites have two distinct grain-scale characteristics associated with (i) magmatic flow igneous structures and (ii) solid-state deformation. The syenites exhibit deformation structures and textures that signify ongoing deformation, commencing in the presence of a melt and concluding under sub-solidus conditions. Syenite deformation is categorized based on mechanical behaviour: an initial phase characterised by the production of diverse magmatic layering and flattened magmatic enclaves, followed by a later stage marked by melt-enhanced embrittlement. The evidence for the end-member conditions of magmatic and solid-state flow is often evident; transitions between these flows may occur during magma cooling, especially during regional deformation. Based on microstructural evidence, we assert that deformation-induced structures extend beyond the solid state; these structures originated in the sub-magmatic stage and nucleated inside partially crystallized magma during the magmatic to sub-magmatic phase.

Danduvaripalle syenites, Magmatic flow, Solid-state flow, Deformation

"Petrographic studies on the Danduvaripalle syenites, Eastern Dharwar Craton, southern India", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.11, Issue 10, page no.e533-e542, October-2024, Available :http://www.jetir.org/papers/JETIR2410458.pdf

"Petrographic studies on the Danduvaripalle syenites, Eastern Dharwar Craton, southern India", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.11, Issue 10, page no. ppe533-e542, October-2024, Available at : http://www.jetir.org/papers/JETIR2410458.pdf