Question

answer the questions below to learn more about the evidence that supports the theory of plate tectonics.

1. based on the theory of plate tectonics, would you expect to find very new rock or very old rock at an oceanic ridge? explain why.
2. based on the theory of plate tectonics, would you expect to find very new rock or very old rock in an oceanic trench? explain why.

Explanation:

1. For the oceanic ridge: Oceanic ridges are divergent plate boundaries where tectonic plates move apart. Magma rises from the mantle to fill the gap, cools, and forms new oceanic crust. This continuous creation means the rock here is always young, as it is newly formed.
2. For the oceanic trench: Oceanic trenches are convergent plate boundaries where denser oceanic crust subducts under another plate. As the crust moves toward the trench, it is older (having formed at a ridge and traveled over time), and as it subducts, it is recycled into the mantle. Only the oldest, farthest-traveled oceanic crust reaches the trench before being destroyed.

Answer:

1. At an oceanic ridge, you would expect to find very new rock. Oceanic ridges are divergent boundaries where new crust forms as magma rises and solidifies, creating young rock.
2. At an oceanic trench, you would expect to find very old rock. Oceanic trenches are convergent boundaries where old, dense oceanic crust (formed at ridges and moved over time) subducts, so only the oldest crust reaches this zone before being recycled.