An earthquake with magnitude of 6.2 on the scale of Richter (6.2 MW) occurred on May 28, 2004 in central Alborz in northern Iran (Firozabad-Kojour) at 17:08:46 local time. Most earthquake research centers reported the epicenter of this earthquake near Firozabad (latitude of 36.283 and longitude of 51.616) at a depth of 28.3 km. Firozabad-Tovir is a small part of the central Alborz Mountains and is actually one of the highly active zones in the region in tectonic terms and the boundary zone of the region. There are two sides of this zone by which the Saudi Arabia zone (considering Eurasia zone) every year moves about 20 millimeters northwards​​. According to the Eurasian zone. This region of Iran is a unique region on the surface of the earth for studying the reaction of the upper crust against continental collision during the late Miocene, considering that it includes the continental shortening due to the north-south collision of the Saudi Arabia and Eurasia zones. Most of the metamorphosis in the Zagros, Alborz, and Kopet-Day areas is consistent in terms of the direction and length of the horizontally-moving faults.
The northernmost part of the Alborz Mountains laterally extends 900 kilometers around the Caspian Sea and 200- 500 kilometers north of the Neo-Tethyan cleavage. (Figure 1)