Question

What evidence first supported the theory of seafloor spreading?

Answer 1

Answer: Sea floor spreading was supported by the following contributions, such as-

1. The convection current at the mantle forces the plates to move against and towards each other.
2. Rocks at the mid-oceanic ridge are younger than the rocks that are away from it.
3. The alternating bands of magnetic field suggested that the poles were continuously shifted during each spreading time.
4. Materials collected from the mid oceanic ridge has been dated and determined the average age of those rock.

Answer 2

1. Rocks near mid-ocean ridge were younger than rock near trenches

2.Matching bands of magnetic rocks were found on either side the mid-ocean ridge; bands like tree rings - record changes in earth's magnetic field over time

3. Earthquake data showed oceanic crust is sinking on to the mantle at trenches