A visual breakdown of the three main layers of the oceanic crust: sediment, basalt, and gabbro, showing their relative thicknesses and positions.
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The Structure of the Seafloor
The Vertical Layers of the Seafloor
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Imagine digging straight down from the bottom of the ocean. You wouldn't hit solid rock immediately. Instead, you would pass through three distinct layers. First, a layer of loose sediment. Second, a relatively thin layer of volcanic rock called basalt. And finally, a much thicker layer of coarse-grained rock called gabbro deep below. This diagram shows exactly how these layers stack up.
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