1.3 plate tectonics

Question 1

what is magnetic striping?

Answer 1

magnetic striping is the zebra-like pattern where there are strips of normal polarity rocks alternating alongside strips of reversed polarity rocks on the seafloor
it is symmetrical on both sides of the mid-ocean ridge.

Question 2

why does magnetic striping occur?

Answer 2

Basaltic rocks from the oceanic crust are volcanic rocks formed from iron-rich lava
They contain magnetic materials
when the iron-rich lava erupts, it cools and solidifies
It’s magnetic materials point towards Earth’s magnetic North, recording evidence of Earth’s polarity at that time.

Question 3

why does evidence of magnetic striping support the plate tectonic theory?

Answer 3

The zebra-like pattern is symmetrical on either side of mid-oceanic ridges. This shows it’s not a random occurrence.
oceanic plates move away from each other, forming new oceanic crust which pushes in both directions away from the ridge.
When Earth’s polarity reverses, the rocks record the reversals.
As more lava moves away from the ridge due to plate divergence, a symmetrical zebra-like pattern forms.