Tiny zircon crystals coughed up by volcanic eruptions on the island of Mauritius are around 2.5-3 billion years old. That’s billions of years older than the island itself; Mauritius is only 8 million years old. The zircons, researchers propose, are remnants of the ancient continent Mauritia that nestled between Madagascar and India before the two landmasses split apart around 84 million years ago.
Comparing the crystals’ ages with those of nearby landmasses, researchers retraced Mauritia’s fate. Volcanic eruptions and shifting tectonic plates fragmented Mauritia and the land was eventually buried under thick layers of lava. Some of that land, including the zircon crystals, was recycled into the rising plume of magma that fuelled the eruptions that eventually built Mauritius.