Imprints of volcanism in the upper mantle beneath the NW Deccan volcanic province

Gurusamy, Mohan; Kumar, M. Ravi; Saikia, Dharmendra; Kumar, K. Ganesh; Tiwari, Pankaj Kumar; Surve, G.

doi:10.1130/l178.1

Cited by 18 publications

(11 citation statements)

References 50 publications

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“…This inference is supported by earthquake tomographic models (e.g., SMEAN, S40RTS, SL2013sv) and corroborated by receiver function studies. Both indicate the existence of predominantly slow upper mantle shear wave velocity anomalies beneath the western side of the peninsula and fast upper mantle shear wave velocity anomalies beneath the eastern side [ Becker , ; Ritsema et al ., ; Mohan et al ., ; Schaeffer and Lebedev , ]. The planform of this distribution shows good spatial correlation with oceanic residual depth measurements (Figure a).…”

Section: Discussionmentioning

confidence: 99%

Cenozoic epeirogeny of the Indian peninsula

Richards

Hoggard

White

2016

Geochem Geophys Geosyst

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Peninsular India is a cratonic region with asymmetric relief manifest by eastward tilting from the 1.5 km high Western Ghats escarpment toward the floodplains of eastward‐draining rivers. Oceanic residual depth measurements on either side of India show that this west‐east asymmetry is broader scale, occurring over distances of > 2000 km. Admittance analysis of free‐air gravity and topography shows that the elastic thickness is 10 ± 3 km, suggesting that regional uplift is not solely caused by flexural loading. To investigate how Indian physiography is generated, we have jointly inverted 530 river profiles to determine rock uplift rate as a function of space and time. Key erosional parameters are calibrated using independent geologic constraints (e.g., emergent marine deposits, elevated paleosurfaces, uplifted lignite deposits). Our results suggest that regional tilt grew at rates of up to 0.1 mm a−1 between 25 Ma and the present day. Neogene uplift initiated in the south and propagated northward along the western margin. This calculated history is corroborated by low‐temperature thermochronologic observations, by sedimentary flux of clastic deposits into the Krishna‐Godavari delta, and by sequence stratigraphic architecture along adjacent rifted margins. Onset of regional uplift predates intensification of the Indian monsoon at 8 Ma, suggesting that rock uplift rather than climatic change is responsible for modern‐day relief. A positive correlation between residual depth measurements and shear wave velocities beneath the lithosphere suggests that regional uplift is generated and maintained by temperature anomalies of ±100 °C within a 200 ± 25 km thick asthenospheric channel.

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Section: Discussionmentioning

confidence: 99%

Cenozoic epeirogeny of the Indian peninsula

Richards

Hoggard

White

2016

Geochem Geophys Geosyst

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“…In NDVP, it is likely that the upper mantle is perturbed due to thermal/compositional anomalies and the lithosphere is thinned due to interaction with the Deccan plume. The results suggest that the upper mantle beneath NDVP retains stronger imprints of Deccan volcanism which was facilitated by the reactivation of the rift systems, in contrast to the SDVP [ Mohan et al ., ]. The SGT, which was under the influence of Marion plume, is characterized by anomalously low upper mantle velocities above 410 [ Srinagesh and Rai , ; Kennett and Widiyantoro , ].…”

Section: Discussionmentioning

confidence: 99%

Low shear velocities in the sub‐lithospheric mantle beneath the Indian shield?

et al. 2013

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[1] Ever since its breakup from the Gondwanaland~140 Myr ago, the Indian plate was ravaged by four hot spots. Although the surface manifestations of such deep processes are evident in terms of large igneous provinces like the Deccan and the fast drift of the Indian plate, the modifications to the deep structure remain to be grasped. In this study, we investigate the mantle transition zone (TZ) structure beneath the Indian shield region using 14,000 teleseismic receiver functions from 77 broadband stations sited on diverse geologic terrains. The arrival times of the P-to-s (Ps) conversions from the 410 km discontinuity at most cratonic stations appear to be delayed by~2 s in comparison with the times observed for other Precambrian shield regions like Africa, Australia, and Canada. Such delays in the conversions from the 410 km discontinuity below the Indian shield suggest low shear wave speeds in the lithospheric and sub-lithospheric mantles due to higher temperatures, together with a thinner high velocity lid that contrasts with a thicker one found beneath most Archean cratons. A thin transition zone beneath most of the cratonic stations lends support to the enhanced temperatures within the TZ itself. Also, a further delay of the TZ discontinuities is observed for stations on the southern granulite terrain, which was under the influence of the Marion plume that is responsible for the separation of Madagascar from India. Although the data do not conclusively show evidence for a 520 km discontinuity, an LVL atop the 410 cannot be ruled out beneath certain geological provinces of the Indian shield.

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“…The NGRI experiments that yielded usable data sets for the present study are SIKKIM (2004–2009, 11 stations) [ Singh et al ., ] in Sikkim Himalaya, APNET (2008–2010, 11 stations) [ Roy et al ., ] in the eastern Dharwar craton, IGP (2006–2009, 11 stations) [ Srinagesh et al ., ] in the Indo‐Gangetic plains, GODAVARI (2006–2008, seven stations) [ Singh et al ., ] in the Godavari Graben, NSL (2008–2010, eight stations) in the Narmada‐Son lineament, NEAST (2000–2005, seven stations) [ Kumar et al ., ] in northeast India, KOYNA (2007–2008, five stations) [ Gupta et al ., ] in the Koyna region, and nine other stations operated by the NGRI since the year 2010 onward, located over different segments of the Indian shield. Apart from these, data from 13 stations being operated by Indian Institute of Technology Bombay (IITB) [ Mohan et al ., ] at different locations in the Deccan volcanic province in different phases during 2002–2009 are used (Figure ).…”

Section: Methodsmentioning

confidence: 99%

Continental scale body wave tomography of India: Evidence for attrition and preservation of lithospheric roots

Singh

Mercier

Kumar

et al. 2014

Geochem Geophys Geosyst

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We assemble P and S waveforms of 2301 teleseismic earthquakes registered at 413 broadband seismic stations spanning the Indian plate from the southern tip of India to the Himalayan collision belt and generate an accurate data set of 52,050 P and 30,423 S arrival times through the multichannel crosscorrelation approach. These traveltimes are then inverted to obtain 3-D P and S velocity structures of the subcontinent at a 2 3 2 lateral resolution. The heterogeneous nature of the Indian lithospheric mantle revealed in this study suggests that the lithospheric roots are not uniformly thick on a regional scale. The key cratonic segments of the Indian shield are characterized by pockets of high velocity anomalies ( 3%) at shallow depths (<300 km), with the diamondiferous regions like Wajrakarur revealing high shear wave anomalies down to 300 km. In contrast to the southern Deccan volcanic province (DVP), the northwestern DVP is underlain by low velocity anomalies at similar depths suggesting that the upper mantle retains imprints of Deccan volcanism which was facilitated by the reactivation of the rift systems.

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Imprints of volcanism in the upper mantle beneath the NW Deccan volcanic province

Cited by 18 publications

References 50 publications

Cenozoic epeirogeny of the Indian peninsula

Cenozoic epeirogeny of the Indian peninsula

Low shear velocities in the sub‐lithospheric mantle beneath the Indian shield?

Continental scale body wave tomography of India: Evidence for attrition and preservation of lithospheric roots

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