Abstract The Earth’s uppermost asthenosphere is generally associated with low seismic wave velocity and high electrical conductivity. The electrical conductivity anomalies observed from magnetotelluric studies have been attributed to the hydration of mantle minerals, traces of carbonatite melt, or silicate m...
ceramic, by a naturally occurring double silicate of alumina and potash which is ground and formed into a thick paste, applied between the two parts to be united and then heated to fuse it. The preferred baking temperature is about 1250 C. and suitable silicates are lapidolite or obsidian. ...
self-irradiation and water corrosion 【4—6】.This point is imp ortant in deep geo logical d isp osal conditions since th e nuclear glass is th e fi rst barrier for the radionuclide release tow ard b io sphere.T he study of very old natural glasses (obsidian and basa...