Petrogenesis of Mesoproterozoic lamproite dykes from the Garledinne (Banganapalle) cluster, south-western Cuddapah Basin, southern India

Abstract

We report mineral chemistry and whole-rock major and trace-element geochemistry for a recent find of Mesoproterozoic (~1.4 Ga) lamproites from the Garledinne (Banganapalle) cluster, south-western part of the PaleoMesoproterozoic Cuddapah Basin, southern India. The Garledinne lamproites occur as WNW-ESE-trending dykes that have undergone varying degree of pervasive silicification and carbonate alteration. Nevertheless, their overall texture and relict mineralogy remain intact and provide important insights into the nature of their magmas. The lamproite dykes have porphyritic to weakly porphyritic textures comprising pseudomorphed olivine macrocrysts and microphenocrysts, titanian phlogopite microphenocrysts, spinel having a compositional range from chromite to rarely magnesiochromite, Srrich apatite and niobian rutile. The Garledinne and other Cuddapah Basin lamproites (Chelima and Zangamarajupalle) collectively lack sanidine, clinopyroxene, potassic richterite, and titanite and are thus mineralogically distinct from the nearby Mesoproterozoic lamproites (Krishna and Ramadugu) in the Eastern Dharwar Craton, southern India. The strong correlation between various major and trace elements coupled with high abundances of incompatible and compatible trace elements imply that alteration and crustal contamination have had a limited effect on the whole-rock geochemistry (apart from K 2 O and CaO) of the Garledinne lamproites and that olivine fractionation played an important role in their evolution. The Garledinne lamproites represent small-degree partial melts derived from a refractory (previously melt extracted) peridotitic mantle source that was subsequently metasomatised (enriched) by carbonate-rich fluids/melts within the garnet stability field. The involvement of multiple reservoirs (sub-continental lithospheric mantle and asthenosphere) has been inferred in their genesis. The emplacement of the Garledinne lamproites is linked to extensional events, across the various Indian cratons, related to the break-up of the Proterozoic supercontinent of Columbia.

A new find of calc-alkaline lamprophyres in Thanewasna area, Western Bastar Craton, India

“…(A) Generalised geological map of India showing the location of the Thanewasna lamprophyre (study area (box)) in the western margin of the Bastar Craton, central India. The occurrence of other lamproites and kimberlites in various cratons is also shown after Chalapathi Rao et al (2016) and (B) geological map of the Thanewasna lamprophyre in the WBC (Dora et al 2017).…”

“…In India, lamprophyres occur in the rocks of various ages, tectonic settings and cratonic areas (Fareeduddin and Mitchell 2012). In the Bastar Craton lamprophyres, lamproite and kimberlite are known to occur in the eastern parts (Mainkar et al 2004;Lehmann et al 2010;Chalapathi Rao et al 2016); however, lamprophyres have not been so far reported from the Western Bastar Craton (WBC). In this communication, a new occurrence Figure 1.…”

Petrogenesis of a nepheline syenite from parts of the Chotanagpur Granite Gneissic Complex: implications for Neoproterozoic crustal extension in the East Indian Shield

“…The Palaeoproterozoic Indian shield subsequently broke up and reassembled in the subsequent supercontinent cycles (Rodinia and Gondwana; reviewed in Meert & Torsvik, 2003;Brown, 2007;Li et al 2008;Bhowmik et al 2012;Sengupta et al 2015;Dasgupta et al 2013a;Chattopadhyay et al 2015;Olierook et al 2019). The Indian shield including the CGGC has been punctured by multiple phases of alkaline magmatism with or without carbonatite (reviewed in Paul et al 2020) and kimberlite/lamproite/lamprophyre (reviewed in Chalapathi Rao et al 2004Rao et al , 2012Rao et al , 2020Rao et al 2016;Sharma et al 2019) that spread over a long stretch of time after the formation of the Indian shield as a part of the Columbia supercontinent. Geochemical and radiogenic isotope data from >1000 Ma kimberlite/lamproite/lamprophyre and the entrained perovskite support the existence of a metasomatized SCLM where DM was the chief component with variable contributions from the asthenospheric mantle (Rao et al 2016;Sharma et al 2019).…”

Geochronology, paleomagnetic signature and tectonic models of cratonic basins of India in the backdrop of Supercontinent amalgamation and fragmentation

“…Zachariah et al (1999) proposed 1756±29 Ma, Pb-Pb date of the dolomite hosted Ur mineralized horizons of Vempalle and Tadpatri Formation. An upper age constraint of 1400 Ma for the Cuddapah deposition is provided by the ages for lamproite dykes intrusive to Cumbum shale, between 1354 and 1418 Ma (Chalapathi Rao et al, 2016Rao et al, , 1996Kumar et al, 2001). The uppermost limit of the sedimentation in the Kurnool Group is assumed to be >1.1Ga, based on the carbonate and limestone xenoliths that were presumably derived from these horizons and hosted the 1.1 Ga Siddanpalle kimberlites of the Raichur kimberlite Field (Chalapathi Rao et al, 2010).…”