Petrology, pseudosection modelling and U-Pb geochronology of silica-deficient Mg-Al granulites from the Jagtiyal section of Karimnagar granulite terrane, northeastern Dharwar Craton, India

Geochronology of the Polycyclic Granulite Terrain of The Eastern Ghats Mobile Belt: An Overview

“…The geochronology of the EGMB can be well correlated with that of the Southern Granulite Terrain (SGT) and the Eastern Dharwar craton as similar ages attributing to the reworking of the metapelites from Madurai section of the SGT have been reported during the Pan-African time which were accreted in the Paleoproterozoic period (Prakash et al, 2010;Brandt et al, 2014). And the Jagtiyal granulites from the Eastern Dharwar craton renders zircon ages having Th/U ratios between 0.16 -0.73 with upper and lower intercepts at 2604 ± 27 Ma and 638 ± 65 Ma respectively (Prakash et al, 2017c) also falls in close correlation with the discussed geochronology of the EGMB which depicts the regional impact of the tectonic and thermal events in the peninsular portion of the Indian subcontinent. Institute of Science, BHU Varanasi, India…”

“…The high Mg-Al granulites of these terrain records orthopyroxenesillimanitesapphirinekornerupine assemblage (Dasgupta, 1995), insisting the temperature to be in between 800-850°C and pressure ranging from 6-10 kbar. In some parts of Mg-Al rich granulites from the EGMB, the peak P-T constraints estimated using conventional geothermobarometers corresponds to the Ultra High Temperature (temperature in excess of 950°C and pressure above 9 kbar) metamorphism (Lal et al, 1987;Prakash et al, 2017c).…”

Reassembly of the Dharwar and Bastar cratons at ca. 1 Ga: Evidence from multiple tectonothermal events along the Karimnagar granulite belt and Khammam schist belt, southern India

“…520-550 Ma) ages from the KGB and suggest that the KGB was not directly involved in these younger collisional events that led to supercontinent amalgamation. The peak metamorphic age of the high Mg-Al granulite in the KGB the area has been recently reported by Prakash et al (2017) as 2604±25 Ma (SHRIMP U-Pb zircon). Granites intruding the supracrustal belt in the KGB are dated as 2490±115 Ma (Rb-Sr whole rock ;Crawford 1969).…”

“…However, Rajesham et al (1993) consider the 2.5 Ga event to represent peak metamorphism of the KGB rocks to granulite grade. Recently, Prakash et al (2017) date this peak metamorphism earlier than the granite event at 2604±25 Ma.…”

“…The 300-km long Bhopalpatanam granulite belt (BGP) lies on the western edge of the Bastar craton (figure 2) and is composed of two pyroxene granulites, ultramafics, quartzite, calcsilicate rocks, Mg-Al metapelites (Vansutre and Hari 2010). The peak metamorphic condition of the high Mg-Al granulite within the KGB is estimated as 7.5-8 kb at 800-840 • C (Prakash et al 2017).…”