Apart from the lithosphere-asthenosphere boundary (LAB), mid-lithospheric discontinuities (MLDs) in thick and old continental lithospheres appear to play an important role global plate tectonics. Initiation of intra-continental subduction, delamination lower lithospheric mantle removal cratonic roots are likely occur along MLDs. Here we introduce ‘pargasosphere’ hypothesis which could account f...

The most stable flow pattern responsible for a ridge transform fault system is studied based on a mantle model of a layered viscous fluid. If the How beneath the ridge is caused by a passive convection, the stable flow on the earth's urface is most likely perpendicular to the ridge axis only for components of small wavelength, less than about 5.5 times of the thickness of the lithosphere, and o...

Introduction: The crustal dichotomy and the Tharsis volcanic province are dominant features at Martian surface. Both exogenic (giant impact) and endogenic (e.g., degree-1 convection) were proposed to explain the dichotomy. In a recent study Zhong [1] proposed a unified model for the Tharsis rise and the dichotomy. A lithospheric thickness variations of hemispherical pattern is assumed, consiste...

[1] Shear wave splitting is a robust tool to infer the direction and strength of seismic anisotropy in the lithosphere and underlying asthenosphere. Previous shear wave splitting studies in the Afar Depression and adjacent areas concluded that either Precambrian sutures or vertical magmatic dikes are mostly responsible for the observed anisotropy. Here we report results of a systematic analysis...

Despite strong anisotropy seen in analysis of seismic data from the NoMelt experiment in 70 Ma Pacific seafloor, a previous analysis of coincident magnetotelluric (MT) data showed no evidence for anisotropy in the electrical conductivity structure of either lithosphere or asthenosphere. We revisit the MT data and use 1D anisotropic models of the lithosphere to demonstrate the limits of acceptab...

6 [1] We present evidence for the existence of an Australian-Antarctic Mantle Anomaly 7 (AAMA), which trends northwest-southeast (NW-SE) through the Australian-Antarctic 8 Discordance (AAD) on the Southeast Indian Ridge (SEIR), is confined to the upper 9 120 km of the mantle beneath the AAD, and dips shallowly to the west so that it extends to 10 a depth of about 150 km west of the AAD. Average...

Abstract Eocene mafic magmatism in the Himalaya provides a crucial window for probing evolution of crustal anatexis processes within lower plate collisional orogen. We report geochemical data from earliest postcollision ocean-island basalt–like dikes intruding Tethyan near northern edge colliding Indian plate. These occurred coeval, and spatially overlap, with granitoids cores gneiss domes were...