Neoproterozoic gneisses at Meatiq and Hafafit in the Eastern Desert of Egypt give Rb–Sr and U–Pb zircon ages of 600–750 Ma. These gneisses are interpreted by different workers to represent deeper levels of juvenile Neoproterozoic crust or Archaean/Palaeoproterozoic crust that was remobilized during Neoproterozoic time. Geochemical and Sr–Nd isotope compositions for these gneisses reported here ...

Subducted lithosphere and crust are chem1cally d1stinct from amb1ent mantle, and some have hypoth.,sized that the result1ng anomdlous buoyancy may affect m1x1ng and, in particular, may CciUSe chem1cal heterogeneity topers ist. To explore th1s effect, two-dimensional convective mix1ng calculations have been carried out. Boundary cond1tions m1micking features of plate kinematics have been imposed...

A broad spectrum of variably altered igneous rocks with a wide range of grain sizes are compressed and heated over a wide range of pressure-temperature paths in subduction zones. Although experimental kinetic data cannot be extrapolated to predict the rates of blueschist and eclogite formation in nature, textural data from rocks indicate that transformation below temperatures of 150øC is minima...

We present the formalism and numerical results for torsional oscillations of relativistic stars endowed with a strong dipole magnetic field, assumed to be confined to the crust. In our approach, we focus on axisymmetric modes and neglect higher-order couplings induced by the magnetic field. We do a systematic search of parameter space by computing torsional mode frequencies for various values o...

abstract this study was carried out in japan for evaluation of the relationship between phenolic compounds and skin color indices of 3 apples cultivars including ‘fuji’, ‘jonathan’ and ‘jonagold’, in 2006. in ‘jonathan’, l* (lightness) increased with decreasing red color of skin. in ‘jonagold’, chroma increased with increasing red color. but in ‘fuji’, there was no detectable difference between...

[1] ODP Legs 129 and 185 sampled the upper 474 m of 170 Ma ocean crust in the western Pacific in order to investigate alteration processes in fast spread crust and to determine inputs to subduction. Fourteen composite bulk samples of altered upper oceanic crust from Site 801 have dO = 8.7–25.7%, dD = 69.4% to 90.4%, and dC = 2.7% to 1.8%. The intensity of alteration and the amount of sediment w...

We present calculations of magnetic field evolution by the Hall effect and Ohmic decay in the crust of neutron stars (NSs). In accreting NSs, Ohmic decay is always the dominant effect due to the large resistivity. In isolated NSs with relatively pure crusts, the Hall effect dominates Ohmic decay after a time tswitch ≃ 104 yr B−3 12, where B12 is the magnetic field strength in units of 1012 G. W...

Superbursts are thought to be powered by the unstable ignition of a carbon-enriched layer formed from the burning of accreted hydrogen and helium. As shown by Cumming & Bildsten, the short recurrence time hinges on the crust being sufficiently hot at densities ρ > 109 gcm−3. In this Letter, we self-consistently solve for the flux coming from the deep crust and core. The temperature where the ca...

The structure of the crust and uppermost mantle beneath Iceland, the keys to understanding the magma plumbing system of the hotspot and hotspot–ridge interaction, was poorly constrained in previous seismological investigations. Here we develop a three-dimensional P-wave velocity model of the Icelandic crust and uppermost mantle from tomographic inversion of over 3500 first-arrivals from local e...

The distinctive rift patterns observed on newly formed lava lakes are very likely a product of interaction between heat transfer (cooling of lava) and deformation of the solid crust in response to applied stresses. One common pattern consists of symmetric “zigzag” rifts separating spreading plates. Zigzags can be characterized by two measurable parameters: an amplitude A, and an angle θ between...