地質學問題X4 請各位幫忙 - 地球科學討論

這是學校的地質學作業
有四題實在不知道該怎麼回答
所以請各位大大幫個忙
謝謝!!
ꌊ1.According to plate tectonic theory where are crustal rocks created ?
Why doesn`t earth keep getting larger if rock is continually created?

2.In part of major mountain belts there are sequences of rocks that geologists
interpret as slices of ancient lithosphere. Assuming that such a sequence
formed at a divergent boundary and was moved toward a convergent boundary
by plate motion,what rock types would you expect to make up this sequence ,
going from the top downward?

3.What might explain the remarkable alignment of Cascade volcanoes?

4.A cross-bedded quartz sandstone may have been deposited as a beach sand or
as a dune sand. What features could you look for within the rock to tell if
it had been deposited on a beach? On a dune?

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