Although continental crust is more or less permanent, the ocean floor is constantly recycled by the tectonic processes that bring about continental drift.

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"At the moment the Seychelles is a piece of granite, or continental crust, which is sitting practically in the middle of the Indian Ocean, " explained Prof Torsvik.

BBC: Fragments of ancient continent buried under Indian Ocean

Plate tectonics, the formation of faults and the moving of the continental crust over a molten interior, is a characteristic unique to Earth and it meant that minerals evolved far beyond those on any other planet in the Solar System.

ECONOMIST: Minerals