Earth's Top Elements
28-Sep-94 00:09:00
Sb: #146969-Earth's Top Elements
Fm: Lanny R. Ream 73512,1163
To: Bill Combs 73524,2651
Bill,
(for anyone reading this message and not the previous one: my figure for the
present day gold grade was as low as 0.03 ounces)
There are lots of them. Generally most metals can be mined at a lower grade
because of improvements in mining techniques and milling/metallurgy processes.
Of course this has to be balanced with the increasing costs of labor,
environmental concerns, etc. I am not a good source for statistics on these, I
don't work in mining geology anymore.
Contact the US Bureau of Mines.
Lanny