（１５點）plate tectonics板塊移動 同 weathering風化 有咩關係？ｔｈｘ！

hmm under the theory of plate tectonics, plates are moved by the subcrustal convection currents in the magma, dragging plates above to collide or move apart by sinking or rising magma respectively. In both cases, volcanic activities is resulted from the movement of magma; thus, magma is ejected to the earth surface. These volcanic activities form rocks: different types of magma would result in different types of rocks, and their properties that determine the weathering of the rock.
For example, with intrusive igneous rocks: this is a rock type formed by slow colling down of magma underground, as the rate of colling down is slower, crystals have enough time to form, like quartz & mica, so the resulted rock is said to be well-jointed with a lots of different types of crystals. an example of this kind of rock is granite. the different kinds of crystals in granite make it more vulnerable to weathering; as the crystals have different rate of expansion and contraction when heated, as time goes by the structure of the rock would be weakened by such activity, causing granular disintigration. The place of its formation is also important, as the rock's originally formed underground with a lot of pressure from rocks overlaying it, once the intrusive igneous rock's exposed to the surface pressure from above is released, thus the rock would have to adapt to the new smaller pressure further making it more vunerable to weathering.
Another example would be extrusive igneous rock,,,
The type of lava ejected would also affect the rate of weathering. Rock formed by basic lava and acid lava is different, as they have differnet basalt level in them...

2008-03-30 02:54:43 補充：
this is what i could think of am not sure about whether it's correct or not at all!
if you're handing this in as a homework please also let me know if i'm right or not,, thx =]

我學緊, 不過無咩關係.......
只係old fold mountain俾weathering eroded, 所以old fold mountain會比young fold mountain short.......