Investigating the geochemical distribution of gold in the sediments of the Ahar 1:100,000 geological sheet using the BLEG method.

The studied area is located in the north-west of Iran within the geological sheet 1:100000 Ahr. Eocene volcanic units cover a large part of the region, and Oligocene granite-granodiorite masses and alkaline granite have penetrated them, and hydrothermal changes and copper-gold mineralization have been created in them. Due to the very high sensitivity of the BLEG method (0.1 ppb) for gold and the possibility of rapid tracking of this element in waterway sediments, this method was chosen to study the geochemical distribution of gold and its anomalous zones in the Ahar sheet. 422 samples were taken from waterway sediments and their gold content was chemically analyzed by fire assay method. After processing the data, 5 gold anomaly zones were identified in the northern half and the central part of the range and the southeastern corner of the Ahar plate. Field studies show that these anomalies are related to the intrusive masses of alkaline granite and Oligocene granite and altered zones resulting from related hydrothermal fluids.