Zagros fold and thrust belt

[2] The Zagros FTB extends for about 1,800 km (1,100 mi) from the Bitlis suture zone in the northwest to the boundary with the Makran Trench, east of the Strait of Hormuz, in the southeast.

[citation needed] The Lorestan (or Lurestan) domain forms the northerly of the two main salients in the Zagros FTB.

[6] Between the two main salients of the Zagros FTB, the Dezful embayment developed in an area that lacked an effective basal Hormuz salt detachment, resulting in a steeper topographic slope of 2°, compared to 1° for both the Lorestan and Fars domains.

In detail the Kazerun fault system consist of a series of en echelon segments within an overall fan shaped zone.

From the focal depth of earthquakes along this zone it is clear that these faults are developed within the underlying basement rocks.

[9] The Persian Gulf and the area of lowland occupied by the alluvial plain of the Tigris–Euphrates river system, known as the 'Mesopotamian Basin', together represent the active foreland basin to the Zagros FTB, caused by the loading of the leading edge of the Arabian plate by the Zagros thrust sheets.

The exact timing of the onset of the subsequent collision is uncertain although there is evidence of some deformation during the deposition of the Asmari Formation in the Oligocene,[11] or possibly as early as the Late Eocene.

The Zagros province includes many giant and supergiant oilfields, such as the Kirkuk Field with over ten billion barrels of remaining oil reserves as of 1998, and the Asmari Reservoir, an Oligocene-Miocene limestone subsequently folded into anticline structural traps during the Zagros Orogeny.