From The Art and Popular Culture Encyclopedia
Geomancy (Greek: γεωμαντεία, "earth divination") is a method of divination that interprets markings on the ground or the patterns formed by tossed handfuls of soil, rocks, or sand. The most prevalent form of divinatory geomancy involves interpreting a series of 16 figures formed by a randomized process that involves recursion followed by analyzing them, often augmented with astrological interpretations.
Once practiced by people from all social classes, it was one of the most popular forms of divination throughout Africa and Europe in the Middle Ages and the Renaissance. Books and treatises on geomancy were published up until the 17th century when most occult traditions fell out of popularity. Geomancy has recently seen a new interest through the works of John Michael Greer and other practitioners, with more mainstream occult circles practicing and teaching geomancy.