Request a Tutor Become a Tutor Decomposition is a biological process that breaks down dead organic matter into simpler organic and inorganic substances. In Archaeology, there are four key stages of decomposition: Hypostasis, Algor Mortis, Rigor Mortis and Putrefaction. To excel in this subject and improve your archaeological skills, check out the list of skilled decomposition tutors in Asa Road, Aba.