Evolution of the Continental Crust in the Proterozoic Eastern Ghats Belt, India and new constraints for Rodinia reconstruction: implications from Sm–Nd, Rb–Sr and Pb–Pb isotopes

Rickers, Karen; Mezger, Klaus; Raith, M.

doi:10.1016/s0301-9268(01)00146-2

Cited by 253 publications

(176 citation statements)

References 74 publications

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“…Sm-Nd whole rock isotopic data of these mafic granulites interbanded with the khondalites indicate the emplacement of their protoliths, the mafic magmatism, between 1.9 and 2.9 Ga ( Table 1). That similar dates were reported by Rickers et al [10] for the precursors of charnockite-enderbite, may not be fortuitous and highlights the fact that hornblende-mafic granulites in both the associations (xenoliths within charnockitic rocks and interbanded with the khondalites) represent the same entity.…”

supporting

confidence: 78%

“…Hence the protoliths of the charnockite-gneiss are mafic rocks, now represented by the hornblende-mafic granulites. This mafic magmatism may be represented by T DM (crustal residence ages) of the protoliths of charnockitic gneiss as between 1.9 and 2.9 Ga [10]. Our Sm-Nd isotopic data on hornblende-mafic granulite xenoliths of both the Eastern Ghats Province (Sunki and Paderu) and Ongole domain (Naraseraopet) indicate the mafic magmatism around 2.5 Ga [22].…”

mentioning

confidence: 65%

“…Beside the polyphase deformation history, the Eastern Ghats Belt is also characterized by polycyclic metamorphic record and dehydration melting in different crustal protoliths [5][6][7][8][9]. However, in view of different crustal residence ages from different parts of the regional granulite terrain, as also distinct isotopic records of granulite facies metamorphism across this regional granulite terrain, the tectonic-metamorphic evolution should be discussed separately for the different crustal domains & provinces identified [10,11]. Barring the Archean domains of Ren- gali and Jaypore, the northern Eastern Ghats Belt, north of the Godavari rift is now described as the Eastern Ghats Province (EGP) and south of the Godavari rift is the Ongole domain (Figure 2).…”

Section: Geological Backgroundmentioning

confidence: 99%

“…In terms of field relation between two major gneiss components, several workers have argued that khondalites or the sedimentary granulites are the oldest components (supposed xenoliths), and multiply intruded by magmatic rocks, including enderbites and charnockites [10,17]. However, the question of the basement to these sediments remains illusive.…”

Section: Field Relation and Fabric Developmentmentioning

confidence: 99%

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Relative Chronology in High-Grade Crystalline Terrain of the Eastern Ghats, India: New Insights

Bhattacharya

Kar²,

Saw

et al. 2011

IJG

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The two major lithology or gneiss components in the polycyclic granulite terrain of the Eastern Ghats, India, are the supracrustal rocks, commonly described as khondalites, and the charnockite-gneiss. Northern Eastern Ghats belt, north of the Godavari rift has been defined as the Eastern Ghats Province, while that to the south has been defined as the Ongole domain; and although, these distinct crustal domains also record different ages of granulite metamorphism, both of these domains are dominated by the two lithologies. Many of the workers considered the khondalites as the oldest component with unknown basement and the charnockiteprotoliths as intrusive into the khondalites. However, published geochronological data do not corroborate the aforesaid relations. Onset of khondalite sedimentation in the Proterozoic Eastern Ghats Province, constrained by detrital zircon data, as around 1.3 Ga and the charnockite-protolith emplacement between 1.9 and 2.9 Ga, argue against intrusion of felsic magma (tonalite, now enderbite!) in to the khondalites. The field relations of the hornblende-mafic granulite with the two gneiss components together with Sm-Nd isotopic data of the hornblende-mafic granulites (both the xenoliths within charnockites and those interbanded with the khondalites) indicate that khondalite sediments were deposited on older mafic crustal rocks. Mafic basement and supracrustal rocks were subsequently deformed and metamorphosed together during collisional orogeny at high to ultra-high temperatures-partial melting of mafic rocks producing the charnockitic melt; and partial melting of pelitic sediments producing the peraluminous granitoids. This is compatible with all the geochronological data as well as the petrogenetic model of partial melting for the charnockitic rocks in the Eastern Ghats Belt. The Ongole domain, south of the Godavari rift, though, is distinct in terms of the age of first/ earliest UHT metamorphism, but here too the charnockite-protoliths are older mafic rocks evidently not intrusive in to the khondalites..

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supporting

confidence: 78%

mentioning

confidence: 65%

Section: Geological Backgroundmentioning

confidence: 99%

Section: Field Relation and Fabric Developmentmentioning

confidence: 99%

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Relative Chronology in High-Grade Crystalline Terrain of the Eastern Ghats, India: New Insights

Bhattacharya

Kar²,

Saw

et al. 2011

IJG

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“…In the Kondapalle region, south of Godavari Rift (Figure 1), an UHT granulite facies metamorphism, with deep crustal heating, resulted in a peak temperature greater than 10008C and pressure greater than 10 kbars, followed by isobaric cooling (IBC) (Sengupta et al, 1999). North of the Godavari Rift (Figure 1), an early UHT ($10008C) metamorphic event (M 1 ) at crustal depths of 30-35 km (8.4 kbars) is reported from high Mg-Al granulites in G. Madugula (Mohan et al, 1997), and several nearby areas including Paderu (Lal et al, 1987;Pal and Bose, 1997;Bhattacharya and Kar, 2002), Anantagiri (Sengupta et al, 1990), Anakapalle (Dasgupta et al, 1994;Sanyal and Fukuoka, 1995;Rickers et al, 2001a;), Araku and Vizianagram (Kamineni and Rao, 1988). Contrasting post-peak IBC and isothermal decompression (ITD) have been recorded from several areas in the Eastern Ghats granulite belt (Lal et al, 1987;Sengupta et al, 1990;Dasgupta et al, 1991;Dasgupta, 1993;Dasgupta et al, 1994;Sen et al, 1995;Bhattacharya, 1996;Shaw and Arima, 1996;Mohan et al, 1997).…”

Section: Metamorphic History Of the Egbmentioning

confidence: 99%

New constraints on the metamorphic evolution of the Eastern Ghats Belt, India, based on relict composite inclusions in garnet from ultrahigh‐temperature sapphirine granulites

Rao

Chmielowski

2011

Geological Journal

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The sapphirine granulites from Gangaraju Madugula, Eastern Ghats Belt (EGB), India preserve a rich variety of mineral assemblages and unique isolated and composite mineral inclusions within garnet that provide robust evidence for extreme crustal metamorphism at ultrahigh temperature (UHT) conditions (>9008C). Diagnostic UHT assemblages in these rocks include sapphirine þ quartz, spinel þ quartz and high alumina orthopyroxene þ sillimanite þ quartz. The stability of spinel þ quartz, sapphirine þ quartz and orthopyroxene þ sillimanite þ quartz assemblages provides evidence for temperatures exceeding 9608C at moderate pressures. The mineral association of garnet-orthopyroxene is indicative of a subsequent high P-UHT metamorphic event as indicated by the high alumina contents of orthopyroxene (>10 wt% Al 2 O 3 ) coexisting with garnet. Peak P-T conditions of $9708C and 9.5 kbars are calculated from conventional garnet-orthopyroxene geothermobarometry. Calculated isochemical sections constructed in the model system Na 2 O-CaO-K 2 O-FeO-MgO-Al 2 O 3 -SiO 2 -H 2 O-TiO 2 -Fe 2 O 3 (NCKFMASHTO) for the sapphirine granulites and garnet-orthopyroxene granulites adequately predict phase relationships that are consistent with those observed in the rocks. An evaluation of the assemblages and textures and P-T estimates indicate a three-stage evolution of the sapphirine granulites and associated garnet-orthopyroxene granulites: (1) inclusion assemblages with sapphirine, spinel and quartz on the low-pressure prograde path (M 1 stage); (2) a peak UHT assemblage of porphyroblastic garnet-orthopyroxene (M 2 stage) and (3) a retrogression that resulted in orthopyroxene-cordierite intergrowths and biotite rims on Grt (M 3 stage). The sapphirine granulites and associated garnet-orthopyroxene granulites indicate that they grew during the prograde and retrograde stage. The thermo-barometric estimates from mineral compositions and the complimentary isochemical sections approached from bulk rock compositions allow tighter constraints to be placed on the P-T evolution of this sector of the EGB.

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Magnetotelluric investigation of the Vestfold Hills and Rauer Group, East Antarctica

Peacock

Selway

2016

JGR Solid Earth

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The Vestfold Hills and Rauer Group in East Antarctica have contrasting Archean to Neoproterozoic geological histories and are believed to be juxtaposed along a suture zone that now lies beneath the Sørsdal Glacier. Exact location and age of this suture zone are unknown, as is its relationship to regional deformation associated with the amalgamation of East Gondwana. To image the suture zone, magnetotelluric (MT) data were collected in Prydz Bay, East Antarctica, mainly along a profile crossing the Sørsdal Glacier and regions inland of the Vestfold Hills and Rauer Group islands. Time‐frequency analysis of the MT time series yielded three important observations: (1) Wind speeds in excess of ∼8 m/s reduce coherence between electric and magnetic fields due to charged wind‐blown particles of ice and snow. (2) Estimation of the MT transfer function is best between 1000 and 1400 UT when ionospheric Hall currents enhance the magnetic source field. (3) Nonplanar source field effects were minimal but detectable and removed from estimation of the MT transfer function. Inversions of MT data in 2‐D and 3‐D produce similar resistivity models, where structures in the preferred 3‐D resistivity model correlate strongly with regional magnetic data. The electrically conductive Rauer Group is separated from the less conductive Vestfold Hills by a resistive zone under the Sørsdal Glacier, which is interpreted to be caused by oxidation during suturing. Though a suture zone has been imaged, no time constrains on suturing can be made from the MT data.

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Evolution of the Continental Crust in the Proterozoic Eastern Ghats Belt, India and new constraints for Rodinia reconstruction: implications from Sm–Nd, Rb–Sr and Pb–Pb isotopes

Cited by 253 publications

References 74 publications

Relative Chronology in High-Grade Crystalline Terrain of the Eastern Ghats, India: New Insights

Relative Chronology in High-Grade Crystalline Terrain of the Eastern Ghats, India: New Insights

New constraints on the metamorphic evolution of the Eastern Ghats Belt, India, based on relict composite inclusions in garnet from ultrahigh‐temperature sapphirine granulites

Magnetotelluric investigation of the Vestfold Hills and Rauer Group, East Antarctica

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