Just some trivials that support the notion that accessing copper...

Just some trivials that support the notion that accessing copper from the ground is changing to to lack of enough open pit discoveries.

This is the crux of it,
"Following the depletion of copper deposits which are accessible via open-cut mines companies are increasing turning to block caving, in which ore is collapsed under its own weight into purpose-designed collection chutes.

Block-cave mining is expected to become the chief means of copper extraction by the end of the decade, yet the new technique is not yet widely taught at tertiary institutions."

http://www.mining.com/rio-tinto-create-worlds-first-virtual-mine-for-training-purposes-30082/

I have no idea the % of block caving now but to be the chief means of extraction in only 8 years is not long in reality.I know we have serious issues in the world economy but what will happen to copper prices if or when people start spending again.I don't wish for silly prices as it can damage economies but it makes you wonder.