CompuServe Messages

Doug >> The pressure between plates need not be of the sort that explodes as magma fountains.<< The very nature of upwelling or moving up should dissipate any power the magma would have unless the pressure was contained…it could offer no power to push. >>I'd be interested to hear exactly what mechanisms the "push" theorists have worked out.<< I would also…anyone listening? >>It is not a "stretch" to jump from moving plates to subduction. If I am convinced by radio-dating, paleomagnetism, hot spot relative-motions, etc. that the sea floor is moving,<< By moving I was not suggesting that it goes anywhere, the motions are adjustments. The earthquakes occur very frequently when the gravitational effects of the sun and moon are certain relationships. I view part of the process as conjunctions of tides below the continents in the liquid layers below the plates. I am still digesting the plastic state you described. Increasing the viscosity would enable a good enough "hold" to do the work necessary to subduct. Even if this condition existed below the plates… and there was a wide area laminar flow the fragile crust would show more evidence of deformation around the subduction areas. For instance …look at the interface between the Pacific and Indo-Australian plates around the Fiji Basin. You have the P plate going under the IA where the Tonga trench is running North and South. The IA plate is going under the P plate at the bottom of New Guinea and the Coral Sea side of Melanesia. The P plate supposedly is subducting under the Fiji Basin comming at it from two sides. Here we have both plates subducting under each other at the same place in the same location with out any fractures or pile ups or any distortions in the fragile crust. With all these motions in mind look at how the North Western Pacific area from the Aleutian Trench Arc around and including the trenches on each side of the Philippine Plate you have motions in many angles both away from certain points and moving towards certain points and the crust shows no distortions warping and bending and melding with very little character deviation aside from seamounts in chains. Why would the crust be fractured when created and smooth where it is denser, thicker and colder. How could the crust stay so level going threw all those perturbations….as it spreads away from itself … and.. converges in on itself? There is no material and certainly not magma that is more fragile when hot than cold. If the process that causes subduction is able to move new ocean basin under the continents at a rate faster than continents build on top of it how did the continental crust form initially? What preserved it when it was a thin sheet like a present ocean basin. The Rises are the most consistent appearing and composed structure on the entire earth. It is also very balanced in its fracture system on each flank of a given section of rise. The trans rise fractures are very parallel to each other and very perpendicular to the symmetrical profile of the rise. They all had a very similar creation process. This Rise formation process included the greatest and fastest shifts on the surface of the earth. These shifted plate fractures are very straight very long and again very parallel with only small angles of change. The plates _both_ shifted….. without a trace of the adjustment farther back from the rise in either direction. How can this be possible? If the process that causes the rise is a somewhat permanent Convection Current….. arranged in a linear formation for millions of years…. why did the convection current upwelling areas shift with the rise when the shift fault movement occurred? Kamron