There is a little twist in the tale though…
I was reading recently, probably in “New Scientist” or “Scientific
American”, that there is a “problem” over the amount of gold in the
earths crust. When you run the model calculations for the formation
of the earth from the cloud of cosmic material, most of the gold
should have gone, along with the iron, to the core. There is too
much in the crust. A possible explanation given was that at some time
after the earth had differentiated into distinct core, mantle and
crust, there was a sufficient bombardment by meteorites (containing
more than average crustal content of gold) to enrich the crust to its
present levels. Subsequently ore bodies have been formed in ways
already discussed.
Nice thought isn’t it … we’re all star-children. – Kevin (NW
England, UK)