Question

The oldest crust on the earth is found at \(\underline{\hspace{1cm}}\).

• A. mid oceanic ridge
• B. subduction zones
• C. sea floor spreading
• D. transform plate boundary

Hint:

Remember the conveyor belt analogy for oceanic crust: it's created at mid-ocean ridges (youngest), travels across the ocean floor, and is destroyed at subduction zones (oldest). The absolute oldest rocks on Earth are found on continents in areas called cratons.

Answer 1

The Correct Option is B

Step 1: Oceanic crust life cycle: Newly formed oceanic crust originates at mid-ocean ridges via sea-floor spreading, making it the youngest.

Step 2: Crust movement and aging: As new crust forms, it pushes older crust away from the ridge, moving across the ocean floor until reaching a convergent plate boundary.

Step 3: Location of oldest crust: The oldest oceanic crust is found at subduction zones, where the dense crust subducts beneath less dense crust, before being recycled into the mantle.