Gary sent in this link to www.dailymail.co.uk/science-tech/article-7733203/ … earth's rocky surface is the result of meteor bombardment as a result of extraterrestrial impacts smashing into the surface of the earth. Billions of years ago is of course. That is where the goal posts are – for whatever reason. A new study has been looking for an explanation for the onset of Plate Tectonics. They came to the conclusion that a bombardment of meteors and other space debris could have kick started the process. Naturally, the research involved modelling simulations – and comparisons with lunar impact studies. They discovered that even after earth had accreted as a body 4.5 billion years ago, earth was still subject to constant bombardment episodes. On the ground, researchers utilised a layer of round particles (see image below) condensed from rock that had been vapourised during an impact event (they date to around 3.2 billion years ago) …
… which is when it is thought Plate Tectonics came into play (at around 3 + billion years ago). It was then speculated, by the researchers, there was a direct connection between the bombardment and the beginnings of Plate Tectonics. It was subsequently then modelled in order to show it was possible.
