CompuServe Messages

HO HO HO!!! Merry Christmas Doug >> Scientific American article that mentions such transitions have actually been observed in olivine. << I remember glancing at the SA article but wasn't that interested at the time……..I'll read the article in SA. I am not denying that the material would get denser a bit if it was forced down. But why would it go down? Its lighter material so it takes a lot of force to push it down. If the Continental mass is overriding it, which could happen if you could get it moving. It would be like an ice breaker. There would be a pile of it out front. Why would it go down? The trenches are not proof it is going down and earthquakes are coming from deep because the crust goes deep. >> There are forces enough to move the continents << What forces? On a plate wide front …what force is in play capable of pushing the mass down. There is no evidence of it cracking where it curves down. It is rigid…. so it can't bend. The thinner the crust is the worse the problem gets for pushing the crust down. The rise pushing along the thread of crust kid of like pushing a stray into wood …tough to do if you do it slow. The crust material is lighter than the material it is on isn't it? It would go down. It would buckle and pile up. As far as pulling down… what would pull it down? It would sure get slippery once it started melting… the puller would lose grip. Why would it go down? What is the state of the different levels. I see the plates as _rigid_ lithosphere. Asthenosphere as a plastic liquid… Mesosphere ? >> The crust does indeed melt during subduction to some extent, hence the volcanoes of the Pacific Ring of Fire. << Why would the melted crust not follow the seam it made. instead it bores a new hole through the lithosphere and pops out as a volcano away from the site of penetration. Why? Even then the volcanoes aren't putting out near enough to vent the melting crust. They are not all even near subduction zones. Kamron (Merry Christmas from a Scientific Christian)