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

Abstract

We describe the mineralogy of a lamproite dyke from Gundrapalli village (Nalgonda district), Telangana, India. The dyke consists of a mineral assemblage characteristic of lamproites in terms of the presence of amphiboles (mainly potassic-richterite together with potassic-arfvedsonite, magnesio-riebeckite, Ti-rich potassic-magnesio-arfvedsonite, potassic-magnesio-arfvedsonite, katophorite and potassic-ferri-katophorite), Al-poor pyroxene, phlogopite (Ti-rich, Al-poor), pseudomorphed leucite, spinel (chromite-magnesiochromite), fluorapatite, baryte, titanite, rutile, barytocalcite, calcite, ilmenite, hydro-zircon, baotite, strontianite, allanite, quartz and pyrite. The absence of wadeite and priderite have been compensated for by the presence of baotite, rutile, titanite, baryte and hydro-zircons. The presence of the secondary phases: allanite, hydro-zircon, chlorite, quartz and cryptocrystalline silica, implies that the dyke has undergone deuteric alteration. On the basis of its typomorphic mineralogy the Gundrapalli dyke has been classified as a pseudoleucite-phlogopite-amphibole-lamproite. We report the presence of the rare mineral baotite from this lamproite, the first recognition of baotite from a lamproite in India. The mineralogy of the baotite-bearing Gundrapalli lamproite is analogous to the baotite-bearing Kvaløya lamproite from Troms, Norway.

Mineralogy of the Marepalli lamproite dyke from the Nalgonda district, Telangana, Southern India

“…The Ramadugu Lamproite Field consists of lamproites dykes named after the local villages and includes: Ramadugu; Somavarigudem; Yacharam; Vattikod; Gundrapalli; and Marepalli (Fig. 2; Kumar et al, 2013;Chalapathi Rao et al, 2014;Gurmeet Kaur et al, 2018;Gurmeet Kaur and Mitchell, 2019). The lamproites of Krishna, Nallamalai and Ramadugu lamproite fields are diamondiferous.…”

Compositional variation and genesis of pyrochlore, belkovite and baotite from the Sevattur carbonatite complex, India

“…The site total charge approach suggests (Nb 5+ 4 Ti 4+ 2 ) Ʃ28+ 0.27 as the most abundant charge arrangement at B-site. Thus, the end-member formula for belkovites from the Sevattur can be written (Krmíček et al, 2011;Kullerud et al, 2012;Kaur and Mitchell, 2019 and references therein). The role of chlorine in baotite structure is enigmatic, commonly it is considered as a neutral species and not required to balance the structure electrostatically (Nekrasov et al, 1969;Nemec, 1987;Potter and Mitchell, 2005;Kullerud et al, 2012).…”

“…Baotite occurs in lamproites, alkali-granite/alkaline pegmatites, and alkaline metasomatites and is usually rich in Ti (Fig. 6) (Kullerud et al , 2012; Kaur and Mitchell, 2019, and references therein). In India, the only reported occurrence is from the Gundrapalli lamproite, Telangana (Kaur and Mitchell, 2019) (Fig.…”

“…6) (Kullerud et al , 2012; Kaur and Mitchell, 2019, and references therein). In India, the only reported occurrence is from the Gundrapalli lamproite, Telangana (Kaur and Mitchell, 2019) (Fig. 6).…”

“…Baotite end-member compositions vary between Ba 4 Ti 8 Si 4 O 28 Cl and Ba 4 Ti 2 Nb 4 Fe 2 Si 4 O 28 Cl (Krmíček et al , 2011; Kullerud et al , 2012; Kaur and Mitchell, 2019 and references therein). The role of chlorine in the baotite structure is enigmatic, commonly it is considered as a neutral species and not required to balance the structure electrostatically (Nekrasov et al , 1969; Nemec, 1987; Potter and Mitchell, 2005; Kullerud et al , 2012).…”