If you're interested in gold reserves by country, here's a pretty cool interactive tool for looking at historic gold reserves since 2000(doesn't require any sign-in to use).

https://www.gold.org/data/gold-reserves

Might explain what China is doing in Africa - another interactive map of gold mines. Just click the country to see what gold mining is going on. http://raregoldnuggets.com/?page_id=1262