Exploration of hidden Pb-Zn deposit through geomicrobiological studies at Irankuh area, Iran

Different methods have been developed for mineral exploration so far, amongst which biological-based methods known as geomicrobiological studies are of the most recent ones. Geomicrobiology as an interdisciplinary approach has achieved great progresses during the past two decades and involves the study of microbes in a number of fundamental geological processes, both in the past and present. The primary purpose of this study was to survey the possible relationship between soil bacterial populations with mineral deposit occurrence underground in order to find biogeochemical anomalies in mineral exploration. Irankuh Pb-Zn mining area located in central Iran was selected as the sampling site in order to evaluate the efficiency of geomicrobiology for exploration of blind deposits. Totally 32 soil samples were collected from 10-30 cm depth and then they are characterized by enumeration of total bacteria and microbial respiration, pH and electrical conductivity (EC) measurements. Furthermore, the isolated bacteria were identified using morphological characteristic tests and 16S rRNA technique. The results showed that while there was no significant relationship between most of soil characteristics (e.g. total bacterial count, pH, EC) and the hidden Pb-Zn mineralization, a class of bacterial colonies (identified as Arthrobacter agilis) was corresponded to the position of mineralization  in the depth. Therefore, an effective biogeochemical exploration technique may be developed through targeting the concentration of Arthrobacter agilis counts in exploration of Pb-Zn mineralization for further detailed exploration activities.