Seismically Derived Gondwana and Proterozoic Sediments East of Cuddapah Basin, South Indian Shield and Its Possible Geotectonic Implications

Chandrakala, K.; Pandey, O.P.; Sai, V. V. Sesha; Vasanthi, A.; Kumar, K.S.

doi:10.1007/s00024-017-1560-8

Cited by 17 publications

(3 citation statements)

References 45 publications

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“…The WDC exposes abundant mature sedimentdominated greenstone belts, whereas EDC exhibits linear, lessabundant volcanic-dominated greenstone belts (Jayananda, Peucat, et al, 2013;Jayananda, Tsutsumi, et al, 2013;Manikyamba et al, 2017;Naqvi et al, 2009). The crustal thickness varies from 42-51 km in WDC to 34-39 km in the EDC (Chandrakala et al, 2017;Gupta et al, 2003;Jayananda et al, 2006;Sarkar et al, 2001). In contrast to greenschist-upper amphibolite grades of metamorphism observed in WDC, the EDC shows lower-upper amphibolitic grades of metamorphism (Jayananda, Tsutsumi, et al, 2013;Swami Nath & Ramakrishnan, 1981).…”

Section: Geological Backgroundmentioning

confidence: 99%

Geochemistry of 2.21 Ga giant radiating dyke swarm from the Western Dharwar Craton, India: Implications for petrogenesis and tectonic evolution

Yadav

Sarma

2021

Geological Journal

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The Western Dharwar Craton (WDC) exhibits numerous exposures of NNW-SSE to NW-SE trending mafic dykes. Geochemistry of four 2.21 Ga NNW-NW trending dykes and 21 other similar trending dykes provides new insights into the geochemical behaviour, mantle source characteristics, and tectonic history of mafic magmatic event, which have also affected the Eastern Dharwar Craton (EDC). Based on modal mineralogy and texture, these dykes can be classified into dolerite, olivine dolerite, gabbro, and olivine gabbro. They show basaltic to basaltic-andesitic composition and have sub-alkaline tholeiitic nature. La N /Lu N ratio classifies the dykes into two groups: Group I, with values close to 2, shows relatively flat REE patterns while, Group II, with values 4-6, has inclined REE patterns. In general, both groups show LREE enrichment and most of the samples exhibit negative Nb-Ta and Ti anomalies, indicating crustal contamination. However, negative Zr-Hf anomaly and low Th/Nb values (0.14-0.73) noticed within the samples preclude significant crustal inputs. Petrogenetic modelling using batch melting equation suggests that the dykes fractionated from two distinct mantle melts and had slightly different sources, both within the spinel-garnet transition zone. The overall composition of these 2.21 Ga dykes is consistent with a mantle plume-induced heterogeneous source that was previously modified by some ancient subduction event. Coeval dykes from EDC exhibit similar geochemical behaviour, mantle source characteristics, and tectonic history. These and other synchronous dykes from distant cratons, viz. Superior, Slave, Greenland, represent a 2.21 Ga large igneous province event, which is linked with the Sclavia/ Superia supercraton.

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Section: Geological Backgroundmentioning

confidence: 99%

Geochemistry of 2.21 Ga giant radiating dyke swarm from the Western Dharwar Craton, India: Implications for petrogenesis and tectonic evolution

Yadav

Sarma

2021

Geological Journal

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“…It is shown as patch number 1 in Figure 1b. Just recently, we made another finding of the 250 m thick Gondwana sediments around the Vinjamuru region of Nellore Schist Belt in the Eastern Dharwar Craton, solely based on seismic studies (Chandrakala et al, 2017), which has a lateral dimension of about 40 km, characterized by a distinct velocity of 4.20 km/s. (patch 3 in Figure 1b).…”

Section: Discussionmentioning

confidence: 99%

Presence of infratrappean Gondwana sediments below Deccan volcanic covered 1993 Killari earthquake region, Maharashtra (India) and geodynamical instability of the south Indian craton

et al. 2023

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KLR‐1 scientific deep borehole, drilled in the 1993 Killari earthquake region of Maharashtra (India), penetrated 8 m thick infratrappean sediments below a 338 m‐thick column of Deccan volcanics that rested over Neoarchean amphibolite to granulite facies mid‐crustal basement. Detailed palynological studies revealed the presence of characteristic Gondwana palynomorphs in sedimentary succession that include Plicatipollenites indicus, P. trigonalis, Parasaccites korbaensis, P. diffusus, Microbaculispora indica, Cyclobaculisporites minimus, Cyclogranisporites barakarensis, C. gondwanensis, Jayantisporites pseudozonatus, Leiosphaeridia bokaroensis, Latosporites sp., Verrucosisporites sp., cf. V. ambiplicatus and Striatopodocarpites gondwanensis. Qualitative analyses of palynomorphs would suggest an Asselian age (298–295 Ma) for their formation and burial in dysoxic to anoxic conditions. Recorded palynological assemblages correlate well with continental Lower Gondwana (Early Permian) sediments of India, as well as other Gondwana continents, indicating a larger extent of Gondwana sedimentation than hitherto known today. Petrological studies indicate the presence of two types of carbonate units that overly the crystalline basement. A relatively coarse‐grained sparry carbonate rock immediately overlies the basement (Sample KIL‐7). The size of the carbonate crystals in the sparite vary from 100 to 500 μm. This unit is overlain by an extremely fine‐grained micrite resembling lime mud (Sample KIL‐6). Micrite is made of carbonate grains with an average size of 10 μm. X‐ray diffraction studies indicate that calcite is the dominant carbonate mineral, while dolomite and quartz occur in minor amounts. Geochemical analyses indicate that in these two samples of carbonate rock that overlie the basement, CaO (33.38 to 38.16 wt %) is higher than MgO (16.0–23.85 wt%). These infratrappeans sediments are also characterized by stable carbon (δ13C) and oxygen (δ18O) isotopic ratios ranging from −1.59 to −8.74‰ and −9.12 to −13.50‰ versus PDB, respectively, thereby conforming to non‐marine fresh water deposits. These findings provide first evidences of reactivation and rifting of Dharwar intracratonic regions during earliest Permian Gondwana Period, which led to severe lithospheric mantle destruction, and massive regional uplift and erosion of the granitic‐gneissic upper crust. Large scale inland‐rifting during the Gondwana sedimentation period was possibly a prelude to India‐Antarctic breakup during the early Cretaceous.

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“…1.315 Ga in a broad subduction setting (Subramanyam et al, 2016). Interestingly, trace of a sedimentary basin has recently been identified inbetween the Archean basement (EDC) and the Nellore schist belt, based on deep sounding seismic data (Chandrakala et al, 2017). The authors consider that the sediment was deposited in this basin from the eroding orogenic belts formed during the assembly of Columbia and Rodinia.…”

Section: The Krishna Provincementioning

confidence: 99%

Geology of the Proterozoic Eastern Ghats Belt: recent developments and outstanding issues

Bose¹

2020

PINSA

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The Eastern Ghats Belt of India has remained a focus for intensive research over three decades. Its unusual rock assemblages, anomalous thermal conditions of metamorphism and consanguinity with the East Antarctica for a considerable geological time has made it a unique case study. This apparently monotonous terrane bears the fingerprint of a complex and fascinating journey of the Indo-Antarctic continental block during Earth's middle age. The paper collates the recent findings from this terrane and presents a status report with yet-to-be resolved issues in the light of current literature.

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Seismically Derived Gondwana and Proterozoic Sediments East of Cuddapah Basin, South Indian Shield and Its Possible Geotectonic Implications

Cited by 17 publications

References 45 publications

Geochemistry of 2.21 Ga giant radiating dyke swarm from the Western Dharwar Craton, India: Implications for petrogenesis and tectonic evolution

Geochemistry of 2.21 Ga giant radiating dyke swarm from the Western Dharwar Craton, India: Implications for petrogenesis and tectonic evolution

Presence of infratrappean Gondwana sediments below Deccan volcanic covered 1993 Killari earthquake region, Maharashtra (India) and geodynamical instability of the south Indian craton

Geology of the Proterozoic Eastern Ghats Belt: recent developments and outstanding issues

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