tectonic processes

Question 1

what is slab pull?

Answer 1

1. newly formed oceanic crust cools to become thicker and denser
2. causing it to sink into the mantle
3. driving force of plate movement

Question 2

what is palaeomagnetism?

Answer 2

1. confirmed seafloor spreading
2. minerals in the rocks match up to the polarity at the time
3. as earth’s magnetic fields (polarity) swap every 400,000 years

Question 3

what is seafloor spreading?

Answer 3

1. mid-ocean ridges and underwater volcanos are formed when magma rises
2. this forms new oceanic crust which moves plates apart