One of the most useful sites on the net is Wikipedia. Here is a link to its entry on Christian Mysticism in Ancient Africa. One of the joys of Wikipedia is its extensive links and - as you will see, dear Reader - there are extensive links here. Happy research and reading!
Christian Mysticism: List of Christian mystics, Christian meditation, Christian mysticism in ancient Africa, Esoteric Christianity,Mysticism, Christian ... Prayer in Christianity, Mystical theology