The Earth ’s encrustation is unique among the known rough humanity of the solar system because it is split into continental plates that shift and interact over eons . This feature is believed to be key to life , and there are many unknowns on how and when it began .
Scientists might have been grow a good idea of the answers to these questions . Research over the last several class has suggestedan in the beginning onrush for home base tectonics . novel study seems to agree with that and has pushed the date even further back to 3.6 billion years ago .
Evidence stick out this scenario , print inGeochemical Perspectives Letters , get along from elements found in some of the quondam zircon in the Earth . The team collected 3,500 tiny zircons from the Jack Hills of Western Australia , which are aged between 4.3 billion year ago to about 3 billion years ago .
These petite gems contain a little bit of atomic number 92 . This chemical element is radioactive and slow decays into other ingredient . By value how much there is , the team can work out how old these mineral are .
" We are reconstructing how the Earth change from a molten ball of rock and metal to what we have today , " study author Michael Ackerson said in astatement . " None of the other planets have continents or liquid oceans or life . In a way , we are trying to answer the doubtfulness of why Earth is unique , and we can answer that to an extent with these zircons . "
Having a database of minerals across such a recollective menstruation of Earth ’s history can let investigator to probe change to our planet . And the scientists in this grouping rule something really interesting : Around 3.6 billion eld ago , the amount of aluminum trap in the zircon increases .
One way for this to happen is for these zirconium silicate to have formed deeper beneath the Earth ’s airfoil . This could paint a picture that the Earth ’s crust was thickening and that architectonic plate had kick off .
" It ’s really hard to get Al into zircons because of their chemical bonds , " Ackerson say . " You want to have pretty extreme geological conditions . "
" This compositional chemise in all probability marks the onrush of modern - style plate plate tectonic theory and potentially could signal the emergence of living on Earth , " Ackerson tell . " But we will need to do a circle more research to determine this geological chemise ’s connections to the origins of life . "
The thickening of the Earth ’s cheekiness around the same time is also suggested from theAcasta Gneissrocks in northerly Canada , but more samples from different places across the globe are necessary to understand the formative days of our planet and how that might have impacted the emergence of life .
