Kinematic and geometry analysis of the Dalan anticline in the central Zagros

The Zagros orogeny as a central part of the Alpine-Himalayan orogenic belt is one of the most seismically active intracontinental fold-and-thrust belts on the Earth, and has an important role in active tectonics of the Middle East. The Hormuz Salt and several intermediate decollement levels, appears to be responsible for the most aseismic deformation of the Zagros sedimentary cover, and also to control the development of a large panel of fold structures, from detachment to fault-propagation folds with varying wavelength and rooting depth. The Dalan anticline located in the Fars province and mantled by soft Oligo-Miocene sediments in SW of the Central Zagros. For the kinematic and geometric analysis of the anticline based on satellite images, geological maps and field observations, three structural cross section perpendicular to fold axis have been studied. Comparing the position of the Dalan fold axis and axial plane in the aa', bb' and cc' cross sections indicates that in the axis of the anticline was rotated about 15 degrees toward the southeast. Regard to interlimb angle estimations and Ramsay classifications from all three cross sections, Dalan anticline is the open fold and 1B-1C classes, respectively. Based on geometrical and kinematic analysis and comparison from studied models such as Sattarzadeh et al, (2000) and Mitra (2003), the Dalan anticline is detachment fold type and compatible with the Lift –off Model With syncline evacuation model. In this model, limb rotation, migration of ductile sediment in outer hinges and syncline to core of anticline occurred.