Although continentalcrust is more or less permanent, the ocean floor is constantly recycled by the tectonic processes that bring about continental drift.
"At the moment the Seychelles is a piece of granite, or continentalcrust, which is sitting practically in the middle of the Indian Ocean, " explained Prof Torsvik.
Plate tectonics, the formation of faults and the moving of the continentalcrust 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.