CompuServe Messages

Hi, Kamron– >> normally convection would cause plumes It sounds reasonable (as reasonable as the flat earth must have sounded once) but it remains proof by assertion until I hear from an expert on convective flows. Convection in a solid, with spherical geometry, is too foreign to our experience to be so dogmatic about. >> The plumes rising to meet the slanted crustal areas would naturally flow upwards towards the mid ocean ridge driving the plate in the wrong direction. There is no reason to assume plumes would arrive in subduction areas. >> As stated the rollers would only develop after the plate started moving so the moving plate would supply the energy for creating the rollers As with your plumes, this seems the best guess, but if your case depends on it, you are in big trouble. Again, the unfamiliarity of the situation is great; the experiment I referred to indicates it could have happened this way, not that it did. Assume only plumes at first – then a plume might break the single world-plate in the beginning (a common pattern in such sheet breakups is to crack in three pieces, with the three cracks meeting at the dome over the plume), causing the three or so new plates to start subducting at some far edge (they were unstable and "itching" to do this anyway, being cold dense material atop warmer lighter material). Now they are moving, and the rollers may become organized by the motion. >> This would work if the shifts occurred back and forth but they are sequential 99% of the time. The next section is moved even farther in the same direction as the previous so again why would the shift fault run into the side B flank when it isn't pulling away…only filling in as you described? It is a relative thing. I cast 1 and 2 as going in opposite directions, but that is from the viewpoint of an observer traveling at an average of their velocities. Let 1 and 2 go in the same direction with 1 pulled harder and faster, and the moving observer will see what I described. >> Also I have one reference showing the magnetic profile of the Mid Ocean Ridge has the same cross-section from one shifted section to the other balanced from the midpoint out on both sides. This eliminates the filling in proposal also. The filling in is at equal rates on both sides of the rift, which was essential to the whole picture I gave of a moving ridge, thus the spreading features are symmetric. >> It is this function that would groom a consistent _worldwide_ crust. The upper layers would cool and sink over and over until the crust material was separated as a lighter material that would eventually float over the heavy material. The Sial crustal material having a lower melting point would not hardened until the magma below it had cooled enough to allow the solidification. This temperature variance insured an even worldwide layer of floating crust. That is the magmatic differentiation I spoke of – this and moderate convections are the main things that could _prevent_ a uniform crust. This differentiation requires very slow cooling in the absence of convection – which I am not convinced is happening at the _surface_ of a lava-hot and _radiating_ Earth. How can convection be less than furious in a magma ocean with savage temperature differentials? >> These shift faults are parallel to the motions that I say occurred in the plates. The shifted mid ocean ridges prove that the event was a simultaineous single rapid event unless we can come up with a plausible reason for the homogeneous continuous mid ocean ridge and the shifted rise sections. The shift faults are parallel to the _relative_ motions of the two plates involved – this is predicted by plate tectonics. I see no proof of rapidity here, especially not in the light of paleomagnetic markings. Above I describe how the regular behavior of the ridges are predictable from plate tectonics – I find it hard to imagine them so regular with so much as you would have going on. >> A catastrophe at the KT boundary is commonly assumed. It is the extent of the catastrophe that is not well known. It is not well known because there is little evidence of any such catastrophe at the K-T boundary. Traces of iridium are _far_ less than one would expect with whole continents literally flying about. Can you not show us even a small jumble of weird rocks between K and T layers? How can that boundary be so thin nearly everywhere? –Doug