Describe the theory of plate tectonics. List at least two lines of evidence used to support the theory.....?

Answer 1

1) subduction zones
2) mid-ocean spreading centers
3) geomagnetic reversals
4) mantle plumes or transport of plates across mantle hot spots (Hawaiian islands, Snake River/Yellowstone hotspot)

Answer 2

A book could be written on your question and still not cover the topic adequately. The theory is that very thin crustal plates are pushed around the surface of the Earth by convection in the underlying mantle. Two lines of evidence supporting this theory are upwelling mantle at the mid-oceanic ridges and subduction zones at some plate boundaries.

Answer 3

Well, to my geographical knowledge plate tectonics is a pretty accepted theroy.

To go back, one must explain continental drift (get my drift)? LOL... on a more serious note, a scientist by the name of Sir Francis Bacon came up with the notion that the earth's contenents fit together like a jig-saw puzzle (For example, Sorth America and Africa can butt right up together, the curve of the western coast of India matches the other side of Africa).

Then this dude, Alfred Wegener (German meteorologist and physicist, of all things) proposed that the continents were once joined together in one single great land mass, which he called: PANGAEA. He said that Pangaea divided into two large continents, Laurasia and Gondwanaland. And like mutatation those broke down into even smaller contintents as the land masses moved apart. He WAS denined of his theory because he couldn't explain how this WORKED!

It wasn't until the late 1960's that this dude in Canada, by the name of Tuzo Wilson said, hey, I can explain Wegener's idea: hence red hot magma from the earth's core heats material (heat causes things to expand and rise - imagine being on your first date .... ;) ) and the heated material causes a current convection flow ... kind of like the heat being ciculated around. As this circualation occurs, it moves the continents from the underlying plates, or large sections of crust!

Wilson coined this progress, "Plate tectonics". Even Wilson's idea was so radical that it was highly disregarded in the social science and a lot of journals (in the 1970's) didn't publish his theory...

So, to expalin how this evidence is plausable, well if your were reading you got one already...as for the second ... the detailed sea-bed analyses confirmed his ideas. How did they get to this? Well, the meaning of SONAR (sound + Navigational + And + Ranging) used by the US military map the sea floor beds in the late 60's. This SONAR was pretty accurate and it depictied the realistic continental shelves!!!

This stuff is really really intesting... I love teaching it as well and I know it becuase my class is studying this very thing this week!!!

Answer 4

adding to the evidence...fossils of the same species match up on the coasts of different continents, as do mountain ranges and geologic formations. also, though this isnt a very scientific answer, the continents look as if they fit together. check out a map. better yet, outine all the continents, cut them out and physically fit them together (great example being S. america and N America). ull be amazed how well they fit