Tectonics is a relatively simple concept: plates of crust bump around on the surface of the earth, and over time they cause changes to the continents and the seas.
What do you know about the mechanism behind plate movement. The theory used to be that convection currents in the upper mantel was what caused the plates to move, but I read somewhere that that theory has fallen out of favor as of late because of the lack of evidence that there actually are such currents. Do you know anything about the latest theories regarding this?
HBD
Whoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for. But until the end of the present exile has come and terminated this our imperfection by which "we know in part," I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca
"Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem.