Applications of Geological methodologies in archeological research have been rapidly increased around the world and developed as a new field known as Geo archaeology. The field Geo archaeology provides the knowledge and the skills to understand the site formation processes, human occupations and their activities. Particle size analysis, organic matter content and phosphate analysis of sediments are commonly used techniques in Geo archaeological studies. Sediments from an excavation carried out in Varana rock shelter no 5, which is a prehistoric site were analyzed by above mentioned Geo archeological methods to study stratigraphic of the sediment layers and prehistoric human occupation.