Development of the Tabriz city on the active North Tabriz Fault

The North Tabriz fault is an active transcrustal strike-slip fault system and one of the main structural elements of northwest of Iran. Having high rate of right lateral displacement (up to 8mm/yr), the North Tabriz fault accommodating the main part of the dextral strike slip displacement of the region. The fault is historically destructive and recently active; it controls the location of many destructive earthquakes. Tabriz and adjacent cities, during their history, have been struck several times by destructive movements of the fault and suffered huge economic losses and human casualties. The last destruction had taken place about 231 years ago. At the foot-hills of the Mount Eynali, Southwest ward, to the Tabriz plain, old fan deposits are elevated and dissected by rivers and drainages, showing recent activity of the Eynali mountain front and progressive on-going quaternary uplift. The field data suggest that in addition to the boundary fault, a blind fault is present that propagates southeastward that is responsible for the neotectonic features that are recently forming at the frontal area of the mountain belt. The regional scale Southeast-vergent overturned anticline and mountain front monocline, widespread uplift of the area north of Tabriz Eynali mountain front, tilting, elevation and channelling of the quaternary fan deposits, the south-ward translation of depot centres of the erosional products from the mountain range, mapped surface rupture and displaced rock units in northern part of the city, are all field evidences for the presence of an actively propagating blind fault