My brother and I were on the big island of Hawaii over winter break, and we got in to an argument on how the cooled lava becomes, over time, capable of supporting plant life.
He said that the major factor in changing lava into soil was the cumulative eroding effects of raindrops bashing the lava into tiny pieces.
I argued that while that certainly happens, the resulting medium – a layer of tiny larva particles – cannot provide the nutrients needed by the lush vegetation that we saw growing there.
I said that a far more important factor was the tiny soil particles and organic matter in those raindrops originating in other parts of the world that are deposited on the lava when they fall.
Who is correct? Or who is more correct?