Neoarchaean felsic volcanic rocks from the Shimoga greenstone belt, Dharwar Craton, India: Geochemical fingerprints of crustal growth at an active continental margin

Physical volcanology and geochemistry of Palaeoarchaean komatiite lava flows from the western Dharwar craton, southern India: implications for Archaean mantle evolution and crustal growth

“…3.38-3.15 Ga volcanic sequences and interlayered sediments (quartzite-pelite-carbonate), indicating detrital zircon ages as old as 3.6 Ga for their provenance (Meen et al 1992;Nutman et al 1992;Peucat et al 1993;Bhaskar Rao et al 2008;Jayananda et al 2008). The TTG and associated Sargur Group greenstone sequences form a basement for the younger 2.91-2.67 Ga Dharwar Supergroup greenstone sequences forming the Bababudan-Chitradurga and ShimogaDharwar basins (Kumar et al 1996;Nutman et al 1996;Trendall et al 1997;Jayananda et al 2013b;Manikyamba et al 2014aManikyamba et al , 2014b. Several late 2.62-2.60 Ga potassic plutons intrude the basement, as well as greenstone sequences forming the terminal magmatic event and reworking corresponding to cratonization of Archaean crust in the western Dharwar craton (Bhaskar Rao et al 1992;Jayananda et al 2006Jayananda et al , 2015Chadwick et al 2007;Sarma et al 2012;Ram Mohan et al 2014).…”

“…3.38-3.15 Ga Mondal et al 2008;Maya et al 2011). Whole-rock geochemical data and Nd isotopes reveal their derivation from heterogeneous mantle sources from different depths Mukherjee et al 2010;Tushipokla and Jayananda 2013;Manikyamba et al 2014b). However, integrated studies involving the combined physical volcanology and geochemistry of komatiites to evaluate the emplacement dynamics of lava flows and chemical and thermal evolution of source mantle havenot yet elucidated sufficient detail.…”

Platinum group element geochemistry and whole‐rock systematics of the Vempalle sills, Cuddapah Basin, India: Implications on sulphur saturation history, mantle processes, and tectonic setting

“…Trace elements (including REE) concentrations were determined by high‐resolution inductively‐coupled mass spectrometer (HR‐ICP‐MS; Nu Instruments Attom, UK) in jump wiggle mode by preparing sample solutions closed vessel digestion method. Sample preparation technique, precision, and accuracy for HR‐ICP‐MS are reported in Manikyamba et al (, ). 103 Rh was used as an internal standard, and external drift was corrected by repeated analyses of standards which were also used as calibration standards accordingly.…”

Archean turbidite hosted orogenic gold mineralization in the Gadag greenstone belt, Western Dharwar Craton, Peninsular India

“…The steep mylonitic zone, a major thrust-fault contact (Chitradurga Thrust Fault) along the eastern margin of the Chitradurga greenstone belt, extending over a length of 400 km from Gadag in the north to Mandya in the south is considered as the boundary between the two blocks (Kaila et al, 1979;Chadwick et al, 2000;Sengupta and Roy, 2012). The volcano-sedimentary association present in the greenstone terrains of the WDC and EDC displays distinct geodynamic settings, as deciphered by recent petrological and geochemical studies (Balakrishnan et al, 1999;Manikyamba et al, 2008Manikyamba et al, , 2014Manikyamba and Kerrich, 2011;Jayananda et al, 2013Jayananda et al, , 2014Ugarkar and Nyamati, 2002;Ugarkar et al, 2000Ugarkar et al, , 2013. Based on combined U-Pb zircon ages and Nd isotope data, the craton has been divided into three provinces western (3.4 to 3.2 Ga), eastern (3.4 to 3.2 Ga) and central with mixed old and younger crust (3.4 to 3.2 Ga and 2.56 to 2.52 Ga) and eastern with mainly younger (2.56 to 2.52 Ga) crust Jayananda et al, 2013).…”

“…Based on combined U-Pb zircon ages and Nd isotope data, the craton has been divided into three provinces western (3.4 to 3.2 Ga), eastern (3.4 to 3.2 Ga) and central with mixed old and younger crust (3.4 to 3.2 Ga and 2.56 to 2.52 Ga) and eastern with mainly younger (2.56 to 2.52 Ga) crust Jayananda et al, 2013). However, the western and eastern greenstone terrains record different geological, geophysical and structural characteristics (Manikyamba et al, 2014;Borah et al, 2014). The WDC is dominated by old basement (N3.2 Ga TTG with interlayered Sargur Group greenstone belts) which is unconformably overlain by 2.9 to 2.7 Ga Dharwar Supergroup volcanosedimentary greenstone belts (Swami Nath and Ramakrishnan, 1981;Nutman et al, 1996;Peucat et al, 1993;Jayananda et al, 2008Jayananda et al, , 2012Sarma et al, 2011).…”