The Role of Chahshak Fault on Quality of Drinking Water Wells Northwest of Mashhad Plain

Mashhad plain in a special structural position and Influenced by the performance of a series of active faults in the northern margin of the Binaloud Mountain Range, The southern margin of the Kopet Dagh Mountain Range and the Quchan Eating Zone is located to the west. The activity of these faults has formed the stepping morphology of lowland rock. Also active faults in the thick Quaternary period and The expansion of alluvial sediments has a high potential for discharge. Chaheshk fault as a subsidiary of Shandiz fault zone in central part of Mashhad plain, It plays an important role in controlling the hydraulic behavior of the groundwater resources of this plain. This fault is based on the integration of geoelectric profiles and The results of machine excavations are first identified in this study.Wells drilled to the north of Chahshak fault with good discharge Often at depths of more than 250 meters, they have been impacted by clayey rocks and Neogene conglomerates. But wells drilled south of the fault with very low discharge and Or no discharge generally at a depth of 100 to 140 meters They have been struck by metamorphic rocks. The uplift of the rock in the south of the Chahshak Fault causes The stepping morphology has been followed by metamorphic rocks in the southern part of Mashhad plain. This metamorphic uplift as a positive flower-like building, Under the influence of a straight-strike strike-slip faulting system, it was created by a trance-tension mechanism.