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The central-western region of the Indian subcontinent hosts the vast geological records of its evolution from the Archean to the Recent, including the youngest (∼65 Ma) episode of the Réunion mantle plume activity that produced a large igneous province, the Deccan Volcanic Province (DVP). A three-dimensional lithospheric resistivity image of central-western India is obtained to understand the lithospheric architecture and map any major eruption channels of the Deccan volcanism as no explicit geophysical revelation of such pathways of magma ascend has yet been made. Two high conductivity (< 30 Ωm) pipe-like geometric features originating from a common deep mantle conductive zone under the Malwa plateau (northernmost lobe of the DVP) and its proximity are detected in the resistivity model. These are interpreted to be remnants of the hitherto unknown primary lithospheric pathways of magma ascent from the deep mantle melt-rich zone related to the Reunion mantle plume upwelling under central-western India. This study gives first compelling geophysical evidence of key eruptive centers of the massive Deccan volcanism in central-western India at a locale not anticipated earlier. High to moderate conductivity crustal zones and weak to moderate lithospheric mantle resistivity in most parts of the study region represent an intense and multiphase tectono-magmatic evolution of the region spanning from the Neoproterozoic to the Cretaceous-Paleogene boundary. [Display omitted] • 3D lithospheric resistivity model of the central-western India. • Conductive pipes originating from a common deep mantle conductive zone. • Remnant mantle pathways of Reunion mantle plume upwelling. • Geophysical evidence of key eruptive centers of Deccan volcanism in India. • Support for the mantle plume theory for the Deccan volcanism. [ABSTRACT FROM AUTHOR]

To decipher the mechanism by which the Phanerozoic accretionary terranes collaged with the Tarim Craton, we constructed a three-dimensional (3-D) lithospheric resistivity model using magnetotelluric data and inversion with testing. The model covers the area across the northern Tarim Craton in the south and the southern Altaids in the north and shows five tectonic-related low-resistivity regions. The low resistivity in East Junggar highlights a Permian rifting zone. The southwest Tianshan low-resistivity anomalies mark asthenospheric upwellings and are related to present-day orogenesis. The intra-crustal low-resistivity area in the northern Tarim Craton could be attributed to metamorphic products from the layered underplating coeval within the Tarim large igneous event. The relatively weak low-resistivity anomalies in Central Tianshan may represent fossil suturing zones. Beneath western Junggar and Chinese North Tianshan (NTS), a large low-resistivity anomaly is continuously distributed in the upper mantle, but spatial correspondence was not shown with the overlying resistivity structure, which could be attributed to the movement of the shallow lithosphere decoupled from the lower lithospheric mantle. We argue that the Yili-Central Tianshan terrane moved northeastward to collage with the Junggar terrane, driving the Junggar terrane rotation and shallow buckling of West Junggar, which constructed the thin-skinned Chinese NTS. The closure of the South Tianshan back-arc basin, associated with southward subduction, completed the amalgamation of peripheral accretionary terranes with the Tarim Craton after the Late Permian. The present study supplies a typical example of the amalgamation of accretionary terranes with a core, thus improving the understanding of continental growth. • We constructed the 3-D resistivity model covering > 600,000 km2. • Our model shows low-resistivities are footprints for tracing lithospheric evolution. • The model supports CAOB collaged with Tarim Craton by back-arc basin subduction. • Thickening is likely a prerequisite for young terranes amalgamating with a core. [ABSTRACT FROM AUTHOR]

Abstract The epicentral region of the 26 January 2001 Bhuj earthquake (7.7 M w) in the Kutch region of India has been experiencing a vigorous and unique intraplate aftershock activity, which shows a V-shaped pattern and N/NE migration along the western margin of the Wagad uplift located to the northeast of the mainshock. This study presents 3D resistivity structure of the Wagad aftershock zone, imaged using magnetotelluric (MT) data, to understand the crustal geoelectric structure and subsurface geometry of faults/lineaments, which could provide critical inputs to evaluate and strengthen the earthquake generation mechanism and aftershocks pattern. The obtained 3D conductivity structure showed a thick (~3 km) and homogeneous conductive (1–30 Ωm) layer of Tertiary/Mesozoic sedimentary cover in the area. A highly heterogeneous upper and middle crust, characterized by a mix of conductive (<30 Ωm) and resistive to moderately resistive (>300 Ωm) structures, is imaged below the sedimentary cover. Enhanced conductivity zones showed spatial correlation with the surface trace of various faults/lineaments and are interpreted as fluid enriched zones in the crust, which play a critical role in earthquake triggering. Significantly higher fluid enrichment noticed in the crust below two minor faults, Khadir Transverse Fault (KTF) and Manfara Fault (MF), which are hitherto considered to have an insignificant role in the seismogenesis of the area. The aftershock events seem to occur mostly on the resistive parts of the crust, and its pattern shows good alignment with the anomalous conductive zones associated to the above two faults. The results provide a strong clue to infer that the KTF and MF have a vital role in the observed aftershock activity and control the V-shaped aftershocks pattern. Highlights • 3D resistivity structure of the 2001 Bhuj earthquake aftershock zone presented. • Heterogeneous crustal structure controlled by fluid enrichment in the fault/fracture zones. • Identified major conductive anomalies beneath two minor faults • Study presents strong clues to explain the peculiar V-shaped aftershock pattern in the area. [ABSTRACT FROM AUTHOR]

Broadband and long-period magnetotelluric (MT) soundings were collected along a 600-km-long EW-trending profile across the southwestern segment of the Jiangnan Orogenic Belt (JOB) to explore the possible remnants of ancient tectonic processes beneath the central South China Block (SCB). Beneath the JOB, the resistivity model reveals a west-dipping, trans-lithosphere conductor (<20 Ω ∙ m) embedded within the relatively thick (80–120 km) and highly resistive (>1000 Ω ∙ m) lithosphere, possibly associated with relics of the Neoproterozoic subduction zone between the Yangtze and Cathaysia blocks. The crustal portion of this conductor is interpreted as solid conducting materials (e.g., graphite, sulfide) that were emplaced into the crust during subduction and orogenesis, whereas its lithospheric mantle portion is more likely to be volatile-bearing minerals formed by subduction-related metasomatic processes. We attribute the greatly reduced asthenospheric resistivities (1~10 Ω ∙ m) below the JOB to low-degree melting of the early-formed metasomatized mantle. In contrast, the lithosphere of the Cathaysia Block is evidently thinned (60–100 km) and segmented by several subvertical, lithospheric-scale conductors (1~30 Ω ∙ m) that are likely associated with fossil fluid pathways along reactivated shear/fault zones. Notably, the thinnest lithosphere sits above a prominent low-resistivity (10 ~ 30 Ω ∙ m) anomaly in the asthenospheric mantle and is spatially coincident with the location of Late Jurassic basaltic outcrops. We interpret these features as signs of lithospheric extension and asthenospheric upwelling driven by roll-back of the Paleo-Pacific Plate during the Late Mesozoic. The results provide key constraints on subduction–accretion tectonics associated with the Neoproterozoic assembly of the SCB and the subsequent lithospheric evolution during the Phanerozoic. [Display omitted] • Dense magnetotelluric soundings reveal high-resolution lithospheric structure beneath central South China. • Relics of Neoproterozoic subduction preserved beneath the Jiangnan Orogenic Belt. • A notably thinned lithosphere is identified beneath the westernmost Cathaysia Block. [ABSTRACT FROM AUTHOR]

Inversion of the magnetotelluric data across the southwestern Taurides reveals two subzones of crust with varying thicknesses: conductive lower crust (<75 Ω m), overlain by resistive (>350 Ω m) upper crust, with four resistive cores (>2000 Ω m) separated by three relatively conductive vertical zones. The first and second vertical zones coincide with surface faults interpreted in Anatolia, such as Fethiye Burdur Fault Zone. The third one is the most conductive and lies in continuity with the Strabo Fault Zone in the Mediterranean Sea. A hypocentral cross section of earthquakes along the profile shows more dense seismic activity in the second resistive core where the conductive crust is not present beneath it. The depth of the crust/upper mantle boundary varies between 30 and 50 km and has an undulating character. The resistivity of the upper mantle reaches 500–1000 Ω m. [Copyright &y& Elsevier]