Neogene Block-Rotation in Central Iran: Evidence from Paleomagnetic Data

Mattei, Massimo ¹; Cifelli, Francesca ¹; Muttoni, Giovanni ²; Zanchi, Andrea ³; Berra, Fabrizio ³; Mossavvari, Fathollah ⁴; Eshraghi, Safar Ali ⁴
(1) Dipartimento Scienze Geologiche, Università degli Studi Roma Tre, Roma, Italy. (2) Dipartimento di Scienze della Terra, Università di Milano, Milano, Italy. (3) Dipartimento Scienze Geologiche e Geotecnologie, Università di Milano-Bicocca, Milano, Italy. (4) Geological Survey of Iran, Tehran, Iran, Islamic Republic of.

A paleomagnetic study was carried out on Oligocene-Miocene sediments from key areas of Central Iran in order to reconstruct the history of tectonic deformation of this region since the Neogene. Paleomagnetic data show that in Central Iran different crustal blocks bounded by sets of strike-slip faults are rotated in opposite directions to accommodate NNE-SSW shortening related to Arabia-Eurasia convergence. Large counterclockwise rotations (20°-35° in average) have been measured in the Tabas and Yazd blocks, south of the Great-Kavir fault, characterized by the presence of N-S to NNW-SSE right-lateral strike-slip faults. Conversely, minor amounts of clockwise rotations have been measured in the Great-Kavir and Torud areas, where ENE-WSW left-lateral strike-slip faults have been recognized. Some of these faults are still active, suggesting that blocks-rotation is still occurring in Central Iran. A block-rotation model is proposed, in which a significant amount of shortening has been accommodated in Central Iran by means of vertical axis rotations, associated on strike-slip faults activity.

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.