ANALYSIS OF SOIL PHOSPHATE AS A TOOL IN ARCHAEOLOGY, CASE STUDY, RIVI, NORTH KHORASAN, IRAN

Phosphate is unique among the elements in being a sensitive and persistent indicator of human occupation. It has long been of interest to archaeologists because of its potential to inform them about the presence of past human activity and to offer clues regarding the type and intensity of human occupation. In fact, the soil of settlements is part of the phosphorus reservoir. The reconstruction of the human activities areas of archaeological sites using soil phosphate analysis is a well-known technique. This study aims to identify and compare the activity area at ancient mounds of Rivi through the measurement of the quantity of phosphates in the soil. In this study, 29 soil samples were collected from the study area, and phosphorus quantity was measured using Spectrophotometry. Multivariate statistical methods were used to classify the obtained results. The results showed that the phosphorus concentrations in the ancient areas were higher than in the control area, and among the ancient areas, the phosphorus quantity related to Rivi B was higher than in other mounds. Previous studies have shown that the Rivi area has been inhabited from around 2900 years ago to the last Sassanian years (1,500 years ago), and in the middle of the Islamic age (1000 years ago), it was a great village. In total, the archaeological site of Rivi was inhabited during the Iron Age, Achaemenid, Parthian, Sassanid, and Islamic periods, and that is why there was a high concentration of phosphorus in the Rivi area compared to the control area.