Early Mesoproterozoic (1.6–1.5 Ga) granulite facies events in the Ongole domain: geodynamic significance and global correlation

Abstract

The late Palaeoproterozoic to early Mesoproterozoic Ongole domain of the Eastern Ghats Belt in southeastern India is composed of a suite of charnoenderbites with enclaves of metapelitic and mafic granulites. Geochemical data for all meta‐igneous rocks are typical for continental magmatic arc suites. The rocks preserve mineral assemblages and reaction textures indicating two separate metamorphic events: an initial counter‐clockwise medium‐pressure ultrahigh temperature (MP−UHT) event (>900 °C at 6.5–7.0 kbar), attributed to the magmatic accretion of the arc, which was followed by a clockwise HP‐MT event (~700 °C at 9 kbar), attributed to its tectonic crustal thickening. Zircon dating of charnoenderbites yield magmatic crystallization ages between 1.75 and 1.70 Ga and metamorphic ages between 1.62 and 1.60 Ga. Syn‐metamorphic enderbites yield magmatic and metamorphic zircon ages of c. 1.60 Ga, overlapping with all other metamorphic rim ages. In contrast, texturally controlled monazite dating of two chemically distinct monazite generations reveals two metamorphic events at c. 1.62 and c. 1.54 Ga. These data suggest that the Ongole domain was formed as a magmatic arc during the Palaeoproterozoic (c. 1.75–1.70 Ga), and subsequently experienced UHT metamorphism accompanied by syn‐metamorphic intrusions at c. 1.60 Ga, suggesting magmatic underplating as the metamorphic heat source. The subsequent crustal thickening at c. 1.54 Ga was due to the collision of the Ongole magmatic arc with the Indian craton. The UHT metamorphism and the related orogenic processes of the Ongole domain fall into the assumed late Palaeoproterozoic to late Mesoproterozoic ‘orogenic and UHT time gap’ (1.8–1.1 Ga) regarded by some studies as an orogenic quiescent period after the formation of the Palaeoproterozoic supercontinent known as Columbia or Nuna at c. 2.1–1.8 Ga. Coeval orogenic processes at c. 1.7–1.5 Ga occurring along accretionary margins in different fragments of Columbia (India, Australia, Antarctica and southwest Africa) indicate a protracted formation of this supercontinent.

Tectonothermal evolution of a collisional orogen in the Khammam region, southeastern India: insights from structures, phase equilibria modeling and U–Th–(total) Pb monazite geochronology

“…The results obtained in this study, together with previous data from the Ongole and Vinjamuru Domains (Gupta et al 1984;Dobmeier et al 2006;Dharma Rao and Reddy 2009;Ravikant et al 2010;Vijaya Kumar et al 2010;Dharma Rao et al 2011a;Chatterjee et al 2016;Sarkar and Schenk 2016;Hrushikesh et al 2019), and Napier-Rayner Complex of East Antarctica (Grew and Manton 1979;Clarke 1988;Grew et al 2001;Harley 2003;Halpin et al 2005Halpin et al , 2007Harley et al 2013), suggest the following regional and geodynamic implications (Fig. S9).…”

Neoproterozoic evolution and Cambrian reworking of ultrahigh temperature granulites in the Eastern Ghats Province, India

“…The Eastern Ghats Mobile Belt is a polymetamorphic terrane located in the east of the Indian peninsula (Figure ). The rocks preserve a varied and complex history spanning the period from the late Palaeoproterozoic to the early Palaeozoic (Dasgupta, Bose, & Das, ; Kelsey et al., ; Rickers, Mezger, & Raith, ; Sarkar & Schenk, ; Simmat & Raith, ; Upadhyay, Gerdes, & Raith, ). Discrete crustal blocks (terranes) bounded by large‐scale shear zone systems have previously been invoked based on the isotopic, metamorphic, and lithological characteristics of the rocks (Rickers, Mezger, et al., ).…”

Petrology and geochronology of a suite of pelitic granulites from parts of the Chotanagpur Granite Gneiss Complex, eastern India: Evidence for Stenian‐Tonian reworking of a late Paleoproterozoic crust

“…The findings of this study, combined with the observations of other workers, reveal that the remnants of~1650-1600 Ma orogenic crust are preserved throughout the E-W-trending composite belt of CITZ. Orogenic belts of~1700-1600 Ma age have also been documented from the Aravalli Delhi fold belt (Bhowmik et al, 2010;Biju-Sekhar et al, 2003;Kaur et al, 2011;Kaur, Chaudhri, Raczek, Kröner, & Hofmann, 2007;Roy, Kroner, Bhattachaya, & Rathore, 2005), western parts of the Eastern Ghats mobile belt (Henderson, (Rogers & Santosh, 2002;Zhao et al, 2002;Zhao et al, 2004 (Pehrsson, Buchan, Eglington, Berman, & Rainbird, 2014;Sarkar & Schenk, 2016). But increasing discoveries of~1700-1500 Ma events from different parts of the world, including this report, advocate the possibility that the formation of Columbia was far more widespread than assumed (Bhowmik, 2019;Cutts et al, 2013;Sarkar & Schenk, 2016).…”

“…For a long time, there has been a gap in geological records regarding high‐grade events during the late Paleoproterozoic to late Mesoproterozoic time (~1800–1100 Ma). So far, it has been attributed to the diminished tectonic activity succeeding the amalgamation of Columbia (Pehrsson, Buchan, Eglington, Berman, & Rainbird, ; Sarkar & Schenk, ). But increasing discoveries of ~1700–1500 Ma events from different parts of the world, including this report, advocate the possibility that the formation of Columbia was far more widespread than assumed (Bhowmik, ; Cutts et al, ; Sarkar & Schenk, ).…”