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| Lost Continent |
Sparkly, iridescent flecks of rocks referred to as zircons from Mauritius date lower back billions of years, to one of the earliest durations in Earth's history, the researchers discovered. other rocks on the island, by contrast, aren't any more than 9 million years antique.
"The truth that we have observed zircons of this age proves that there are a great deal older crustal materials under Mauritius that might handiest have originated from a continent," Lewis Ashwal, lead author of the brand new have a look at and a geologist on the university of the Witwatersrand, Johannesburg in South Africa, stated in a assertion.
Earth's crust is made of two elements: the planet's continents, which upward push excessive above the oceans due to the fact they may be composed of lighter rocks inclusive of granite; and the sea basins, which sink lower due to the fact they are made from denser rocks inclusive of basalt, in line with a video approximately the brand new look at. whereas the continental crust can be 4 billion years old, oceanic crust is a good deal younger, and is continually being formed as molten rock spews through fissures inside the ocean floor, called midocean ridges.
The conventional thinking is that the island of Mauritius turned into fashioned with the aid of volcanic pastime stemming from any such midocean ridges, which means older crust shouldn't be there.
but the new have a look at indicates that a tiny sliver of a primeval continent could have been left behind while the supercontinent Gondwana cut up up into Africa, India, Australia and Antarctica greater than 200 million years ago. Then, the fiery start of the island included the primeval rock in layer after layer of cooling lava, constructing up the bulk of the island that is seen today, the researchers stated.
"in line with the new effects, this breakup did not involve a simple splitting of the historic supercontinent of Gondwana, but alternatively a complex splintering took place, with fragments of continental crust of variable sizes left adrift in the evolving Indian Ocean basin," Ashwal stated.
the new findings buttress effects from a 2013 study that still discovered traces of historic zircons in beach sand on the incredibly younger island. however, critics contended that this zircon may want to have traveled there in trade winds or been carried alongside on someone's footwear. within the new observe, however, the zircons were found embedded in 6-million-year-antique rock referred to as trachyte, ruling out the belief of wind-blown switch, Ashwal stated.
The findings have been published Tuesday Jan. 31 in the journal Nature Communications.
