The initial isotopic compositions of Nd and Sr in basalts from the Central Siberian Plateau and other major continental flood basalts are reported. The continental flood basalts appear to be the product of partial melting of mantle sources that consist of relatively primitive undifferentiated material and are clearly distinct from midocean ridge basalts, which sample mantle reservoirs that have...

[1] The shear tractions that mantle flow exerts on the base of Earth’s lithosphere contribute to plate-driving forces and lithospheric stresses. We investigate the sensitivity of these tractions to sub-lithospheric viscosity variations by comparing shear tractions computed from a mantle flow model featuring laterally-varying lithosphere and asthenosphere viscosity with those from a model with l...

We investigate the influence on mantle convection of the negative Clapeyron slope ringwoodite to perovskite and ferro-periclase mantle phase transition, which is correlated with the seismic discontinuity at 660 km depth. In particular, we focus on understanding the influence of the magnitude of the Clapeyron slope (as measured by the Phase Buoyancy parameter, P ) and the vigour of convection (a...

To help determine the chemical composition of the Earth’s mantle, we characterised the high-pressure mineral assemblage of an undepleted natural peridotite—thought to be representative of the Earth’s upper-mantle—to 107 GPa using high-resolution X-ray diffraction. At lower-mantle conditions, the peridotite transforms to the assemblage 76 (F 2)% (Mg0.88Fe0.05 2 + Fe0.01 3 + Al0.12Si0.94)O3 ortho...

BACKGROUND Mantle cell lymphoma (MCL) is an aggressive type of B-cell non-Hodgkin's lymphoma that originates from small to medium sized lymphocytes located in the mantle zone of the lymph node. Extra nodal involvement is present in the majority of cases, with a peculiar tendency to invade the gastro-intestinal tract in the form of multiple lymphomatous polyposis. MCL can be accurately diagnosed...

[1] We show that time‐dependent models of mantle upwellings above a cold downwelling in the New Zealand‐Antarctica region since 80 Ma can explain anomalous geophysical observations: ∼1.0 km of positive residual bathymetry at the Antarctica margin, a large Ross Sea geoid low, 0.5–0.9 km of excess tectonic subsidence of the Campbell Plateau since 80 Ma, and several seismic wave speed anomalies. M...

[1] Abstract: We predict plate motions from a comprehensive inversion of theoretical estimates of tectonic forces in order to evaluate the relative importance of these and the uncertainties of such models. Plate-driving forces from the mantle are calculated using global flow models that are driven by tomography and subduction-derived density fields. Observed and predicted plate velocities agree...

[1] The vertical coherence of mantle structure is of importance for a range of dynamic issues including convective mass transport and the geochemical evolution of Earth. Here, we use seismic data to infer the most likely depth ranges of strong, global changes in the horizontal pattern of mantle heterogeneity. We apply our algorithm to a comprehensive set of measurements, including various shear...

[1] We analyze moment tensor solutions from deep subduction zone earthquakes to determine global slab deformation patterns. Inferred strain rates are compared to predicted deformation patterns from fluid models to help constrain the first‐order radial and lateral viscosity structure of the Earth. While all slabs that reach the lower mantle are compressed at their tip, intermediate depth pattern...

[1] Using an integrated geophysical and geological approach based on a comparative analysis of 27 different parameters, we investigate both the location and origin of the source material for hot spot volcanoes. We report a significant correlation between extreme geochemical compositions of lavas with both shallow seismic velocities and the depth extent to which a hot spot source can be traced w...