Oceanic Crust
The oceanic crust of Earth is roughly about 8 kilometers thick with its main component being a rock called basalt (National Geographic Kids, 2015). Alden (2015a) states that this part of the crust covers approximately 60 percent of the Earth’s surface – residing for the majority underwater -and only accounts for 0.1 percent of Earth’s entirety. Alden (2015a) goes on to explain that the oceanic crust is no more than roughly 180 million years old, defining this as young, and it is about 20 kilometers thick, which is relatively thin in comparison to the continental crust and the other layers of Earth. Upon the oceanic crust is the last layer of the Earth, the continental crust.