Redefining Dharwar Craton-Southern granulite terrain boundary in south India from new seismological constraints

Das, Ritima; Rai, S.S.

doi:10.1016/j.precamres.2019.105394

Cited by 11 publications

(10 citation statements)

References 52 publications

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“…We first obtained Rayleigh wave phase velocity maps in the period range of 30-140s and then computed the shear wave velocity model by inverting dispersion curves at 0.5° grid spacing. The crustal model was constrained from an earlier study with joint inversion of receiver function and ambient noise data (Das & Rai, 2019). We summarize our primary findings below.…”

Section: Discussionmentioning

confidence: 99%

“…We used the initial crustal velocity model derived from joint inversion of receiver function and ambient noise data (Das & Rai, 2019) along with the initial mantle velocity to a depth of 350 km from Shapiro and Ritzwoller (2002). We performed three different inversions; (a) using our phase dispersion data (30–140s) alone, (b) combining it with 1‐D crustal velocity model of Das and Rai (2019) and (c) combining it with short period (5–20s) group dispersion data of Das and Rai (2019) (Figure S6 in Supporting Information S1). The result of using a constrained crustal model is similar to inclusion of the short‐period group dispersion data.…”

Section: Methodsmentioning

confidence: 99%

“…Based on the above experiments, we inverted the dispersion data at each grid node at a 55 km interval using an initial model comprising crustal velocity from Das and Rai (2019) and the upper mantle velocity to a depth of 350 km from Shapiro and Ritzwoller (2002). The inverted 1D velocity models at different grid nodes are then combined to produce a 3D shear velocity model.…”

Section: Methodsmentioning

confidence: 99%

“…We used the initial crustal velocity model derived from joint inversion of receiver function and ambient noise data (Das & Rai, 2019) along with the initial mantle velocity to a depth of 350 km from Shapiro and Ritzwoller (2002). The result of using a constrained crustal model is similar to inclusion of the short-period group dispersion data.…”

Section: Shear Velocity Modelingmentioning

confidence: 99%

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Lithospheric Structure of the South India Precambrian Terrains From Surface Wave Tomography

Mullick

Saha

2022

JGR Solid Earth

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Cratons are the oldest regions of the Earth with generally undeformed crust since the Paleoproterozoic (Lee et al., 2011). They form the interior shield of continents with very little topography and are surrounded by mobile belts that are successively younger toward the continental margins. Most of the cratons are underlain by thick (150-250 km), cold and buoyant lithosphere composed of depleted mantle with 20%-30% melt removed. Partial melting and melt extraction in the Earth's upper mantle can significantly modify the composition and therefore the geophysical properties of the solid residues (Afonso & Schutt, 2012). The highly depleted rocks can be significantly less dense and generally seismically faster than their fertile counterparts. The cratonic lithosphere is generally characterized by high shear wave velocity (>4.6 km/s), low surface heat flow (<40 ± 11 mW/m 2 ) and lower density due to the presence of highly melt-depleted peridotites abundant in forsterite-rich olivine

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…We used the initial crustal velocity model derived from joint inversion of receiver function and ambient noise data (Das & Rai, 2019) along with the initial mantle velocity to a depth of 350 km from Shapiro and Ritzwoller (2002). The result of using a constrained crustal model is similar to inclusion of the short-period group dispersion data.…”

Section: Shear Velocity Modelingmentioning

confidence: 99%

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Lithospheric Structure of the South India Precambrian Terrains From Surface Wave Tomography

Mullick

Saha

2022

JGR Solid Earth

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show abstract

“…The nature of the boundary between the southern part of the Dharwar Craton, an Archean granulite terrain, and the abutting Proterozoic Southern Granulite Terrain (SGT) is debated for over ~75 years. A high resolution 3D shear wave velocity model of the region was generated by Das and Rai (2019) using joint inversion of PRFs and surface waves derived from ambient noise cross correlations. The inversion results beneath the southern part of Dharwar Craton reveal an unusually thick (15-28 km) high-velocity layer (HVL) in the lowermost crust with Vs>4.0 km/ s that continues coherently southward to well beyond the southern limb of the Palghat-Cauvery shear zone (PCSZ).…”

Section: South Indian Shieldmentioning

confidence: 99%