2015 GCSE 21st Century Physics P1 P2 P3

You know the specification statement: "Understand how rocks provide evidence for changes in the Earth (erosion and sedimentation, fossils, folding)" what exactly does it mean? Can someone explain pls

Basically seafloor spreading

You know the specification statement: "Understand how rocks provide evidence for changes in the Earth (erosion and sedimentation, fossils, folding)" what exactly does it mean? Can someone explain pls

ohhhh and you know how the mantle is a solid then how do tectonic plates float on a solid

ohhhh and you know how the mantle is a solid then how do tectonic plates float on a solid

ohhhh and you know how the mantle is a solid then how do tectonic plates float on a solid

Does anyone know what 2 factors produce rock stripes of alternating polarity? don't understand that shizz

To say the least, I'm panicking so much. Although P123 is one of my stronger physics module "groups" I'm still stressing since I suck at Physics. Literally.

Same the thing is though all of the 1,2,3s are all the easiest modules out of the 7 so it can only get harder


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so as magma that rises from the mantle cools, it gets band of normal or reversed polarity. This is due to the iron in the magma aligning with the earth's magnetic field which changes direction every half a million years. These bands will be symmetrical either side of the oceanic ridge showing clear patterns. This is convincing evidence that new sea floor is being made and continents are moving apart.

Let me know if that explanation isn't good enough!

Basically...
when studying rocks, it tell us about the Earth's structure and how it has changed.

Through the erosion process we can tell that the Earth's surface is made of rock layers. The oldest rock is usually at the bottom. the layers are compacted sediment, produced by weathering and erosion.

when looking at mountain formation we can tell that the earth would have eroded down to sea level if mountains weren't being formed.

we can look at craters on the moon, as the surface is covered with impact craters from meteors, we can also tell that they have hit earth but have been erased by erosion.

we can also look at the radioactivity of rocks. A rock's radioactivity decreases over time and radioactive dating measure radiation levels to find a rock's age.

we can also look at fossils of animals and plants in sedimentary rock layers, which shows how life has changed.

Most of these are in the revision guide.