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The Madurai block, the largest crustal block in the Precambrian Southern Granulite Terrane of south India, preserves rare assemblages of high- to ultrahigh-temperature metamorphic rocks. These rocks bear exclusive evidence for the high thermal regime prevalent during their formation and can be constrained from accessory phases such as zircon, monazite and garnet. Here, we present the P-T-t evolutionary history of garnet-cordierite-spinel granulites from different localities in the Madurai block. Combined petrography, mineral reaction, geothermobarometry and pseudosection modelling of the samples record HT to near-UHT metamorphic conditions with clockwise P-T trajectories. LA-(MC)-ICPMS U-Pb/Hf isotopic studies on zircons point to Paleoproterozoic high-grade metamorphism in the area with juvenile magmatic signatures. LA-ICPMS/EPMA monazite dating constrains the timing of HT to near-UHT metamorphism at ~580 and ~550 Ma. The heat source required for the Paleoproterozoic high-T event is correlated with the synchronous igneous emplacements reported in the region, whereas the heat source responsible for the Neoproterozoic HT to near-UHT event can be related to the processes associated with crustal thickening and synchronous mafic emplacement. The clockwise P-T trajectories of these granulites are interpreted as the signature of collisional orogeny prevalent in the region during the final stages of Gondwana assembly. [ABSTRACT FROM AUTHOR]

Petrology, geothermobarometry, and phase equilibrium modelling of garnetiferous felsic gneiss from Grovnes peninsula in the Larsemann Hills of Prydz Bay, East Antarctica provide pristine evidence for the preservation of high-grade metamorphic imprint in the area. The metamorphic evolution of the sample is demonstrated by the development of the assemblage Grt+Bt+Melt+Pl+Sill+Kfs+Qtz+Ilm at peak metamorphic conditions of ∼790 °C and ∼7.5 kbar, which subsequently underwent retrogression and cooling to lower P-T conditions along a clockwise path. Texturally constrained chemical dating of monazites constrain the timing of peak metamorphism and garnet formation at ∼575 Ma, whereas the apatite U–Pb ages constrain cooling ages at ∼518 Ma. The clockwise P˗T˗t trajectory of the studied samples, together with the Ediacaran-Cambrian metamorphic/cooling ages demonstrate the long-lived nature of metamorphism in Prydz Bay, which is ascribed to collisional tectonism prevalent during the final stages of the assembly of East Gondwana supercontinent. Similar results from adjacent continental fragments including Sri Lanka, Eastern Ghats Belt, Madagascar, and South India suggest their coeval metamorphic evolution during the East African orogeny. • Clockwise P-T evolution of high-T garnetiferous felsic gneiss from Larsemann Hills. • Timing of peak metamorphism and cooling constrained at ∼575 Ma and ∼518 Ma. • Ediacaran-Cambrian metamorphism in Larsemann Hills and its tectonic significance. [ABSTRACT FROM AUTHOR]

Geochemical and zircon U–Pb age data on granites of the Chitrial area, situated at the NE part of the Eastern Dharwar Craton, are presented to elucidate their petrogenesis, time(s) of emplacement, and role in crust formation. Based on field and geochemical characters, these granites are classified as alkali feldspar/monzo‐granite. Whole‐rock data of selected samples show evolved calc‐alkaline and peraluminous characters with high SiO2, K2O, large‐ion lithophile element, and light rare earth elements (LREE), depleted heavy rare earth elements (HREE) and strongly negative Eu anomaly. One sample shows slightly different character with low SiO2, enriched light rare earth elements, and depleted heavy rare earth elements without Eu anomaly. Geochemical analyses suggest that the rocks are S‐type granite with syn‐collisional and volcanic arc signatures. These granites define a coherent trend favouring low pressure crystallization of the magma. U–Pb zircon data show that the crystallization ages of the granites vary within 2514 ± 10 to 2525 ± 24 Ma. The geodynamic evolution of the Eastern Dharwar Craton is discussed wherein subduction and deep burial of sediment is envisaged to cause partial melting and granite genesis in the craton. [ABSTRACT FROM AUTHOR]

[Display omitted] • Duration of sedimentation in the Srisailam sub-basin was > 1840 Ma ≤ 1770 Ma. • The Srisailam Formation formed in a passive margin setting. • The dominant source area for the Srisailam Formation was the Dharwar Craton. • The Srisailam Formation contains Palaeo-Mesoarchaean and traces of Haedean zircons. • The Srisailam Formation is correlated with the Pulivendla Formation, Chitravati Group. The Mesoproterozoic Cuddapah Basin consists of four unconformity-bound sequences, i.e., Papaghni Group, Chitravati Group, Srisailam Formation and Kurnool Group. A fair amount of geochronological and geochemical data is available from the basal Papaghni Group and Chitravati Group as well as the overthrusted Nallamalai Group. Due to limited geochronological and geochemical constraints, the Srisailam Formation, however, remains a subject of speculation regarding the time of sediment deposition, sediment source locations, and tectonic setting. In this work, we present new geochronological and geochemical data (zircon U-Pb) from samples of the Srisailam Formation. The new data suggest that the Srisailam Formation correlates temporally with the basal Chitravati Group and is largely disparate from the allochthonous Nallamalai Group. The sediments of the Srisailam Formation contain a minor yet significant number of Palaeo-Mesoarchaean detrital zircon with traces of Haedean zircon. Based on our detrital zircon data, we argue that the sedimentation in the Srisailam sub-basin initiated after ca. 1840 Ma and continued till ≤ ca. 1770 Ma and the sediments were mainly sourced from Neoarchaean to Paleoproterozoic terrains including the Dharwar Craton, and sedimentation was initiated in a rift basin that subsequently evolved to a passive margin setting. [ABSTRACT FROM AUTHOR]