[1] Seismic velocity discontinuities within the top 1000 km of the Earth beneath southern Africa are imaged by stacking about 1300 source-normalized broadband seismograms recorded by the Southern African Seismic Experiment. The Moho, 410, and 660 kilometer discontinuities are clearly detected. The mean mantle transition zone thickness is 245 km, essentially the same as the global average, sugge...

Using seismic data from regional earthquakes in Tibet recorded by the Hi-CLIMB experiment, Pn attributes are used to constrain the velocity gradient and attenuation structure of the Tibetan lithosphere under the Hi-CLIMB array. Numerical modeling is performed using the spectral-element method (SEM) for laterally varying upper-mantle velocity and attenuation, and the seismic attributes considere...

The Late Aptian Rajmahal Traps originated through Kerguelen-Plume-related volcanism at the eastern margin of Indian Shield. Clinopyroxene and whole-rock thermobarometry reveals that magmas crystallized P-T conditions ≤~5 kbar/~1100–1200 °C. These pressures correspond to upper crustal depths (≤~19 km). Modeling shows primary were last in equilibrium with mantle ~9 kbar/~1280 corresponding (~33 k...

The upper lithospheric structure from the Pilbara Craton, across the Capricorn Orogen, to the northern Yilgarn Craton is determined from high-fidelity broadband seismic data. Three-component temporary stations were deployed in a line running southwards from Marble Bar, Western Australia, at approximately 118 E longitude. They were in position between July and October 2000. Receiver functions ar...

The driving mechanism that is responsible for the uplift of intracontinental mountains has puzzled geologists for decades. This study addresses this issue by using receiver function images across the Chinese Tianshan Mountains and available data from both deep seismic profiles and surface structural deformation. The near-surface structural deformation shows that the Tianshan crust experienced s...

[1] Stacking of approximately 1500 radial receiver functions recorded at about 80 broadband seismic stations deployed in southern Africa reveals systematic spatial variations in the ratio of crustal P and S wave velocities (F), crustal thickness (H), and the amplitude of the converted Moho phases (R). The eastern Zimbabwe and the southern Kaapvaal cratons are characterized by small H ( 38 km), ...

[1] Large igneous provinces are characterized by magmatic activity on two distinct timescales. While these provinces have total active lifetimes of order 10–30 Ma, most of the erupted volume is emplaced within 1 Ma in many cases. The longer timescale is consistent with plume or tectonic models for mantle melting responsible for flood volcanism, but the shorter “main stage” timescale is enigmati...

[1] The Cenozoic rift system of Baikal, located in the interior of the largest continental mass on Earth, is thought to represent a potential analog of the early stage of breakup of supercontinents. We present a detailed P wave velocity structure of the crust and sediments beneath the Central Basin, the deepest basin in the Baikal rift system. The structure is characterized by a Moho depth of 3...

The Moho discontinuity is one of the fundamental boundaries on Earth, separating crust from upper mantle. Arrival times seismic reflection and refraction data are used to estimate depth Moho, but nature remains illusive. We present a synthetic seismogram modelling study for suite possible velocity models oceanic lower transition zone (MTZ). For modelling, we have 45-km long multichannel streame...

the mapping of the crust-mantle boundary surface is an important geophysical task, which the method of seismic profiling has dealt with profitably. there are, however, areas where the crustal structure is not known up to the present, and where the moho has as yet not been determined by geophysical sounding. in such areas the isostatic theory may be applied to give a first estimate of the depths...