And indeed it would take another five decades for geologists to figure out how convection within Earth’s mantle - the thick layer of hot rock between the crust and core - propels the plates on the surface. How could giant landmasses move? Wegener couldn’t identify a mechanism to drive his drifting continents. When the geologist Alfred Wegener first proposed the theory of continental drift in 1912, most of his colleagues thought it was preposterous. “There’s a lot of different people, coming from very different perspectives, coming up with a convergence of 3.2 to 3 billion years,” said Collins. It “supports the growing consensus in the geological community that plate tectonics established itself at a global scale” sometime around 3 billion years ago, he said. The findings buttress other circumstantial evidence accrued over the last decade pointing to that date, said Richard Palin, a petrologist at the University of Oxford.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |