When and how did continents formed on Earth ?

  RESEARCHERS have provided a new insight on how continents are formed early in Earth history. You in your junior classes might have thought about the formation of continents of our planet, but what do you think about continents on Mars after we colonize it, - ''Will there be continents on Mars ? "

                  A research led by a University of Calgary geophysicist provided strong evidence against continent formation above a hot mantle plume, similar to an environment that presently exists beneath the Hawaiian Islands. 

                  The analysis indicates that the nuclei of Earth's continents formed as a byproduct of mountain-building processes, by stacking up slabs of relatively cold oceanic crust, which created thick, strong 'keels' in the Earth's mantle that supported the overlying crust and enabled continents. But analyzing this was not an easy part, it required high technology computer professionals and the specific technology.

                  The Department of Geoscience's Professor David Eaton developed computer software to enable numerical simulation of the diffusive cooling of Earth's mantle over a time span of billions of years. Developing this software is the greatest innovation in the field of geoscience.

                  Working in collaboration with former graduate student, Assistant Professor Claire Perry from the University du Quebec a Montreal, Eaton relied on the geological record of diamonds found in Africa to validate his innovative computer simulations.

                 Now the most important question we have is - When did  continents formed ?. Earlierly on earth there were supercontinents, the most recent of these supercontinents was called Pangaea, which means "all lands."  

                 It began to break up about 200 million years ago, first forming the two supercontinents Gondwana (in the Southern Hemisphere) and Laurasia (in the Northern Hemisphere). This are the only two supercontinents which formed continents which we know today.Less well-known are the supercontinents that are thought to have existed before Pangaea. One such example is Rodinia, the supercontinent though to have existed around 1.1 billion years ago;  it began to break apart 800 million to 600 million years ago.

             Geologists call this continual breaking apart and coming together of the continents the supercontinent cycle. And that cycle is likely  still going. The continents are still on the move, drifting apart at the rate of about an inch each year, typically spreading in mid-ocean.

            The movement, and all the bumping and grinding it causes as plates dive under continents, creates earthquakes, fuels volcanoes and builds mountains. As they gradually move over millions of years, the continents as we know them today could crash together again to make yet another supercontinent, geoscientists say.

The study has been published in Nature Geoscience.