What part of Africa did gold deposits in regions near major rivers such as niger come from?

Guinea, country of western Africa, located on the Atlantic coast. Three of western Africa’s major rivers-the Gambia, the Niger, and the Sénégal - rise in Guinea. Natural resources are plentiful: in addition to its hydroelectric potential, Guinea possesses a large portion of the world’s bauxite reserves and significant amounts of iron, gold, and diamonds. Nonetheless, the economy is largely based on subsistence agriculture