Petrology and petrogenesis of Mesoproterozoic lamproites from the Ramadugu field, NW margin of the Cuddapah basin, Eastern Dharwar craton, southern India

Mineralogy of the baotite-bearing Gundrapalli lamproite, Nalgonda district, Telangana, India

“…1; Neelkantam, 2001; Fareeduddin and Mitchell, 2012 and references therein). The lamproite fields in the Eastern Dharwar block are: (1) the Wajrakarur field with the P2-West, P12, P5, P13, P4, TK1 and TK4 intrusions which were classified formerly as kimberlites, but have been reclassified recently as lamproites (Gurmeet Kaur et al ., 2013; Gurmeet Kaur and Mitchell, 2013; Gurmeet Kaur and Mitchell, 2016; Shaikh et al ., 2017; Shaikh et al ., 2018); (2) the Cuddapah Basin lamproites with the Chelima, Zangamarajupalle, Garledinne, Banganapalle intrusions (Chalapathi Rao et al ., 2004; Chalapathi Rao et al ., 2016 and references therein); (3) the Krishna lamproite field (Chalapathi Rao et al ., 2010 and references therein); and (4) the Ramadugu lamproite field (Chalapathi Rao et al ., 2014; Gurmeet Kaur et al ., 2016; Gurmeet Kaur and Mitchell, 2017; Gurmeet Kaur et al ., 2018 and references therein). The Eastern Dharwar block lamproite emplacement/event preceded the global kimberlite event at 1.1 Ga (Kumar et al ., 2007; Tappe et al ., 2018 a ; Talukdar et al ., 2018 and references therein).…”

“…The Ramadugu dykes are emplaced in the Peninsular Gneissic Complex of the Eastern Dharwar block (Fig. 2; Sridhar and Rau, 2005; Ahmed and Kumar, 2012; Kumar et al ., 2013; Chalapathi Rao et al ., 2014; Gurmeet Kaur et al ., 2018). The Gundrapalli dyke of the Ramadugu lamproite field was discovered by Ahmed and Kumar (2012).…”

“…Rutile is a late-stage phase associated with titanite. Rutile, although not a common and representative phase of lamproites, has been reported previously from some Indian lamproites (Mitchell and Fareeduddin, 2009; Chalapathi Rao et al ., 2014; Gurmeet Kaur et al ., 2018). The other accessory groundmass phases are: titanite, allanite, calcite, baryte, hydro-zircon and baotite (Figs 5 c–d and 6 b–d ).…”

“…Titanite occurs as aggregates and is mainly associated with amphibole, rutile and baotite. Titanites have also been reported from other Indian lamproites (Chalapathi Rao et al ., 2014; Gurmeet Kaur et al ., 2018). Calcite is commonly present as a late-stage residual groundmass phase.…”

Mineralogy of the Vattikod lamproite dykes, Ramadugu lamproite field, Nalgonda District, Telangana: A possible expression of ancient subduction-related alkaline magmatism along Eastern Ghats Mobile Belt, India

“…The analysis of altered rocks is not a useful endeavour and can lead to completely inappropriate genetic conclusions. In this work, using a mineralogical-genetic system (Mitchell, 1995; Mitchell and Bergman, 1991) we classify the dyke rocks in the Vattikod area as bona fide lamproites and show these to be members of a suite of lamproites emplaced along the eastern margins of the Eastern Dharwar Craton (Ahmed and Kumar, 2012; Kumar et al ., 2013 a ; Chalapathi Rao et al ., 2014). On the basis of our classification we make further inferences as to the role of subduction in their genesis but no claims that these rocks are analogous to young Mediterranean-type lamproites.…”