Crustal geodynamics from the Archaean Bundelkhand Craton, India: constraints from zircon U–Pb–Hf isotope studies

Abstract

A comprehensive study based on U-Pb and Hf isotope analyses of zircons from gneisses has been conducted along the western part (Babina area) of the E-W-trending Bundelkhand Tectonic Zone in the central part of the Archaean Bundelkhand Craton. 207 Pb-206 Pb zircon ages and Hf isotopic data indicate the existence of a felsic crust at ß 3.59 Ga, followed by a second tectonothermal event at ß 3.44 Ga, leading to calc-alkaline magmatism and subsequent crustal growth. The study hence suggests that crust formation in the Bundelkhand Craton occurred in a similar time-frame to that recorded from the Singhbhum and Bastar cratons of the North Indian Shield.

Unravelling the record of Archaean crustal evolution of the Bundelkhand Craton, northern India using U–Pb zircon–monazite ages, Lu–Hf isotope systematics, and whole-rock geochemistry of granitoids

“…Similar lower intercept ages have also been reported during previous studies on the granitoids from the Bundelkhand Craton (Saha et al, 2011(Saha et al, , 2016Kaur et al, 2014;Verma et al, 2016). Taken together, these substantiate a Pan-African overprint in the region.…”

“…In-house TIMS value of 1027 ± 1 Ma is for the Namaqua monazite (Axel Gerdes, GUF Frankfurt, personal communication). et al, 1998, 2002Pati et al, 2010 ;Saha et al, 2011Saha et al, , 2016Kaur et al, 2014 and this study), South India (Dharwar Craton and Coorg Block ;Guitreau et al, 2012 ;Ram Mohan et al, 2013Santosh et al, 2015Santosh et al, , 2016Jayananda et al, 2015), Pilbara Craton (Smithies and Champion, 2000 ;Hickman and Van Kranendonk, 2012 ;Kemp et al, 2015), North China Craton (Zhao andCawood, 2012 andreferences therein) andKaapvaal Craton (Pojoul et al, 2003;Zeh et al, 2009Zeh et al, , 2011Zeh et al, , 2013bTaylor et al, 2012;Laurent and Zeh, 2015). Mohan et al, 2014), L'2015(Lancaster et al, 2015, Sa'2015(Santosh et al, 2015 and Sh'2016 (Saha et al, 2016).…”

“…Palaeoarchaean magmatic events are also reported from the western part of the Bundelkhand Craton (around Babina), where TTG gneisses intruded at 3440 ± 3 Ma and contain zircon xenocrysts with ages up to 3589 ± 8 Ma (Saha et al, 2016). A probable phase of TTG intrusion at 2669 ± 7 Ma has also been reported from the same area (Verma et al, 2016); however, in the absence of geochemical data, it is difficult to conceive whether it is a TTG sensu stricto or grey gneiss.…”

“…Tonalite gneiss of ~3.56 Ga (Ghosh, 2004) from the same craton shows nearly identical age to that of 3.55-3.59 Ga TTG gneiss in the Bundelkhand Craton (Kaur et al, 2014;Saha et al, 2016). The oldest rock from the Singhbhum Craton, a dacitic lava, yielded an age of 3.51 Ga (Mukhopadhyay et al, 2008), and a dioritic gneiss on the fringe of Coorg Block in southern India provided an age of ~3.50 Ga (Santosh et al, 2016).…”

Geochemical evidence of an extraterrestrial component in impact melt breccia from the Paleoproterozoic Dhala impact structure, India

“…; Saha et al. ; and references therein). Other rock types include banded iron formation, amphibolite, calc‐silicate rocks and metapelites (Saha et al.…”