"Plates move over mantle. Is the mantle pushing the plates? Is the mantle doing nothing?" van Hinsbergen said.
According to conventional theory, convection -- the mantle's motion caused by the transfer of heat from the Earth's core to the outer layer -- causes tectonic plates to move and grind against each other.
Van Hinsbergen's hypothesis is that the mantle is in fact "a big lake of rock that is essentially not convecting," which he said would require a complete rethink.
"If that is true, then everything that we see, at least on timescales of tens of millions of years and shorter, is driven by gravity pulling plates down. And that would make the whole system a lot simpler," he said.
The mission received funding from a Dutch program for -- in van Hinsbergen's words -- "ideas that are almost certainly wrong but if they're not they will have big implications."
The samples collected have been taken to Europe for analysis and the results are expected to be known later this year.
