Relationship between plate tectonics and rock formation/characteristics?

Mikeyt086

This question was put to me, and all i could think of is continental drift as Wegner (?) said the examples of fossils and sediments were the same on some coasts.

So, as the thread title suggests im trying to find a relationship between the theory of plate tectonics and the formation of rocks.

Can anyone provide more info?

Scarinae

Um, your question is quite vague, so I'm not sure how exactly to go about answering it. Plate tectonics is pretty important to the formation of igneous and metamorphic rocks in particular, but also sedimentary rocks to a degree.

I'm assuming you know the basic difference between the types of rock - the simple explanation is that igneous rocks are those formed from magma, such as basalt; sedimentary rocks are made from the accumulation of sediments like sand or mud, such as sandstone; metamorphic rocks are igneous or sedimentary rocks that have undergone intense heat and/or pressure that changes their structure and sometimes composition

The most obvious way that plate tectonics affects rock formation is at the plate boundaries. There are different ways that the plates interact - in some places, they move apart (diverge) eg. the great rift valley of eastern Africa; in other places, the plates collide (converge) eg. India is crashing northwards into Asia, resulting in the Himalayas. Sometimes the plates rub past each other, such as the San Andreas fault

Where the plates move apart, magma comes up from deep in the earth, and solidifies into rock - if you look at where the plates diverge in the mid-Atlantic, there is a huge ridge of newish basalt (you can see it on Google Earth)
Where plates collide, they get buckled and squashed and metamorphose the rock - the Himalayas are a perfect example of this
Sometimes when one plate goes under another (subduction), the intense pressure melts the rock and makes it come to the surface and form volcanoes - for example, the Mediterranean is very gradually closing as Africa moves northwards, resulting in an arc of volcanoes in the sea, including well-known ones such as Vesuvius, Etna, Thera etc

Plate tectonics can also influence the formation of sedimentary rock - sometimes when the crust gets stretched you get deep basins where sediment accumulates, and gradually forms into rock over millions of years

Let me know if you want me to elaborate on any of that!