Shirmaghz bentonite deposit is located close to Shirmaghz village, 51 km north east of Ghaen city and 35 km south of Geysur village, Eastern Iran, in central Iran geological zone and north part of Lut block subzone. According to the field evidences, microscopic studies and based on ICP-MS chemical analysis of trace and rare earth elements (REEs), the parent rocks of Shirmaghz bentonite deposit are mainly acidic to intermediate volcanic rocks such as dacite and andesite belongs to Calc-Alkaline magmatic series along with pyroclastic tuffs. minor amounts of Basalt are also present. ASTER Satellite Images processing determined distribution of clay minerals in the investigated area.
Mineralogical analysis on Shirmaghz bentonite samples done by optical microscopy and XRD. Chemical analyses were performed by XRF and ICP-MS. The XRD results confirmed that smectite group minerals mainly of beidellite and Na-montmorillonite are the major clay minerals of the investigated area. Furthermore, The Chemical analyses of major oxides by XRF, indicates the mean values of Na₂O is 2.21% and CaO is 0.77%. The chemical analysis results also shows that the high percentage of SiO₂, (65-70 %) and moderate amonts of Al2O3, (11-13.5%). These chemical analysis indicates that Shirmaghz bentonite deposit is Na type. The higher amounts of SiO₂ suggests the hydrothermal origin of this deposite which were resulted from alteration of volcanic and pyroclastic rock units that are directly in associate with fault zones.
Based on physical, chemical and industrial properties of Shirmaghz bentonite deposit, the most important industrial applications of this bentonite is in casting and iron pelletizing industries.