This is the crust hiding under all that salty water. It’s the thin, young, and heavy one.
Average thickness? Only about 5 to 10 kilometers. That’s basically a pancake compared to continental crust. Flat as a board.
It’s made of basalt—a dark, dense volcanic rock. Think black sand beaches and lava flows. Very dramatic.
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Earth's Crust Explained | Definition, Facts & Examples
And it’s young—like, teenager young. The oldest oceanic crust is only about 200 million years old. That’s a blink in geological time.
Why so young? Because it’s constantly being created and destroyed. It’s the ultimate drama queen of the crust family.
New oceanic crust forms at mid-ocean ridges. Magma oozes up, cools, and poof—new seafloor. It’s like Earth’s own conveyor belt.
Then it gets shoved back down into the mantle at subduction zones. Goodbye, crust. Hello, recycling bin.
