Why is there so much gold in west Africa?
Wed Feb 26 2025
Militaries that have taken power in Africa’s Sahel region – notably Mali, Burkina Faso and Niger – have put pressure on western mining firms for a fairer distribution of revenue from the lucrative mining sector.
Gold is one of the resources at the heart of these tensions. West Africa has been a renowned gold mining hub for centuries, dating back to the ancient Ghana empire, which earned its reputation as the “Land of Gold” because of its abundant reserves and thriving trade networks. The region remains a global leader in gold production. As of 2024, west Africa contributed approximately 10.8% of the world’s total gold output.
But why is there so much gold in this region? The Conversation Africa asked geologist Raymond Kazapoe to explain.
How is gold formed?
The simple answer here is that we are not certain. However, scientists have some ideas.
Gold, like all elements, formed through high energy reactions that occurred in various cosmic and space environments some 13 billion years ago, when the universe started to form.
However, gold deposits – or the concentration of gold in large volumes within rock formations – are believed to occur through various processes, explained by two theories.
The first theory – described by geologist Richard J. Goldfarb – argues that large amounts of gold were deposited in certain areas when continents were expanding and changing shape, around 3 billion years ago. This happened when smaller landmasses, or islands, collided and stuck to larger continents, a process called accretionary tectonics. During these collisions, mineral-rich fluids moved through the Earth’s crust, depositing gold in certain areas.
A newer, complementary theory by planetary scientist Andrew Tomkins explains the formation of some much younger gold deposits during the Phanerozoic period (approximately 650 million years ago). It suggests that as the Earth’s oceans became richer in oxygen during the Phanerozoic period, gold got trapped within another mineral known as pyrite (often called fool’s gold) as microscopic particles. Later, geological processes – like continental growth (accretion) and heat or pressure changes (metamorphism) released this gold – forming deposits that could be mined.
Most gold production and reserves in west Africa are found within the west African craton. This is one of the world’s oldest geological formations, consisting of ancient, continental crust that has remained largely unchanged for billions of years.
Source: https://www.thehindu.com/