Ancient micro-continent identified under the Indian Ocean

Scientists at the University of Liverpool have found evidence of an ancient micro-continent buried beneath the Indian Ocean.

The ancient continent extends more than 1500 km in length from the Seychelles to the island of Mauritius and contains rocks as old as 2,000 million years, much older than the Indian Ocean which has formed only in the last 165 million years.

Mauritia
The research team believe that this micro-continent, which they have named Mauritia, was split off from Madagascar and India between 61 and 83 million years ago as one single land mass rifted apart to form the continents around the Indian Ocean that we know today. Much of it was then smothered by thick lava deposits as a result of volcanic activity and submerged beneath the waves.

Scientists from the University of Liverpool's School of Environmental Sciences  used satellite derived data to map crustal thickness under the Indian Ocean.

''Our expertise in mapping crustal thickness beneath the oceans has revealed many large areas where the crust is much thicker than normal''Using geophysical data processing techniques the team were able to identify areas where the crust beneath the sea-floor was up to 30km or more thick, the same thickness as continental crust but much greater than that of oceanic crust which is on average only about 7 km thick.

Collaborating researchers from Oslo University analysed sand grains from beaches in Mauritius, a volcanic island about 900 kilometres east of Madagascar.  They found the sand contained tiny crystals of ancient zircon, a mineral normally associated with a continental crust and dated between 660 million and two billion years old, a lot older than the sand grains which were formed from the nine million-year-volcanic activity on Mauritius.