Relationship between regional geochemical anomalies with Sentinel 2 satellite images using spectral clustering at the 1:100,000 scale Chahar- Farsakh sheet, South Khorasan

The 1:100,000 scale Chahar-Farsakh sheet in South Khorasan province has a high potential for regional exploration.due to its volcanic and plutonic rocks and the presence of metamorphic rocks containing mineralization and metal indices. Determination of composite geochemical anomalies for 20 elements by spectral clustering method on the stream sediment data of this sheet suggests 6 areas for mineralization. In the second stage, Sentinel 2A satellite images of the study area were used because they had more bands and higher spatial resolution of 10 and 20 meters. By clustering the sentinel 2A satellite images into 5 clusters, the optimal clustering obtained with Silhouette index shows that the spectral behavior of the second cluster pixels is similar to the spectral behavior of igneous and metamorphism rocks. Therefore, two geochemical anomaly areas located in this cluster have been proposed as the first priority of mineralization according to other exploration data. The pixels of the fourth cluster have a spectral behavior similar to sedimentary rocks, and the two geochemical anomaly areas located in this cluster are considered for the second exploration priority. Comparing the location of the pixels of the first, third and fifth clusters with the geological map of the study area and studying their spectral behavior also shows that these clusters overlap with the Quaternary alluvial and terrace sediments, which have not the value of mineralization. The results of this study show that the clustering of the satellite data can be used to validate regional geochemical anomalies and to prioritize them.