CompuServe Messages

Hi, Kamron– >> Could it be that subduction is so necessary to explain the new ocean basins that we are interpreting the data in a convenient way? A lot of geologists had to be dragged kicking and screaming into the plate tectonic consensus by the facts – I am sure they had to do a lot of looking for other fits to the facts, including other explanations for young (to a geologist) sea floors, but each "fit" attempt dissolved when subjected to examination and test. If these had not been tried pretty thoroughly, too many holdouts would remain. It is not impossible the seismic readings do not mean what we think, but until stronger evidence shows up, it is not wise to bet against them. What else could they represent? >> Why would the lighter material be assimilated into the heavier material? Because they are roughly the same elements in roughly the same ratios. Put basalt under high pressure and temperature, and the atoms will be rearranged to match the mantle rock (from which the basalt originally came) at whatever depth it has reached. Ice will be assimilated by water, or vice versa, whichever way the temperature dictates. This takes a while, so if the basalt keeps sinking, it may get a little deeper than the mantle it is matching, but sooner or later the currents will stir them up together until their origins are lost. Your line of barges might be sunk by a line of lighter barges, if the lines are pushed together hard enough and there are big enough waves (or beveled bows) enough to allow the lighter ones to start an edge atop the heavier ones. If our "sonar" (seismic mapping) showed barges underwater in expected positions near other appropriately moving barges, it would be reasonable to assume that this happened, and that there was some driving force even without certainty of its exact nature, especially with several plausible candidates vying for attention. –Doug