How old is the Earth's crust?

Decaying atoms traced in zircon uphold dating of Earth's crust at about 4.374 billion years old. read more

The Earth’s crust is its lightest, most buoyant rock layer. Continental crust covers 41percent of the Earth’s surface, though a quarter of that area is under the oceans. The continental crust is 20 to 80 kilometers thick. Its rocks hold four billion years of Earth history. The remainder of the Earth is covered by oceanic crust. read more

The crust of the Earth is of two distinctive types: Oceanic: 5 km (3 mi) to 10 km (6 mi) thick and composed primarily of denser, more mafic rocks, such as basalt, diabase, and gabbro. Continental: 30 km (20 mi) to 50 km (30 mi) thick and mostly composed of less dense, more felsic rocks, such as granite. read more