In 1967, a Malawian farmer stumbled upon a hidden hoard of eight copper ingots buried beneath a tree. Now, more than half a century later, scientists have traced the metal to its source: a copper mine nearly 800 km (500 miles) away.
In 1967, a Malawian farmer stumbled upon a hidden hoard of eight copper ingots buried beneath a tree. Now, more than half a century later, scientists have traced the metal to its source: a copper mine nearly 800 km (500 miles) away.
