TY  - JOUR
A1  - Cifelli, Francesca
A1  - Ballato, Paolo
A1  - Alimohammadian, Habib
A1  - Sabouri, Jafar
A1  - Mattei, Massimo
T1  - Tectonic magnetic lineation and oroclinal bending of the Alborz range: Implications on the Iran-Southern Caspian geodynamics
T2  - Tectonics
N2  - In this study we use the anisotropy of magnetic susceptibility (AMS) and paleomagnetic data for deciphering the origin of magnetic lineation in weakly deformed sedimentary rocks and for evaluating oroclinal processes within the Arabia-Eurasia collision zone. In particular, we have analyzed the Miocene Upper Red Formation (URF) from the outer curved front of the southern Central Alborz Mountains of north Iran, to test for the first time with paleomagnetic data the origin (primary versus secondary) of this orogenic arc. AMS data document the existence of a magnetic lineation parallel to the orientation of the major tectonic structures, which vary along strike from WNW to ENE. These directions are highly oblique to the paleoflow directions and hence suggest that the magnetic lineation in the URF was produced by compressional deformation during layer-parallel shortening. In addition, our paleomagnetic data document clockwise and anticlockwise rotations along vertical axis for the western and eastern sectors of the Central Alborz Mountains, respectively. Combined, our results suggest that the orogen represents an orocline, which formed not earlier than circa 7.6Ma most likely through bending processes caused by the relative motion between the rigid crustal blocks of the collision zone. Moreover, our study provides new insights into the Iran-Southern Caspian Basin kinematic evolution suggesting that the present-day SW motion of the South Caspian Basin with respect to Central Iran postdates oroclinal bending and hence cannot be as old as late Miocene to early Pliocene but a rather recent configuration (i.e., 3 to <1Ma).
KW  - oroclinal bending
KW  - magnetic fabric
KW  - Alborz range
KW  - Southern Caspian Basin
Y1  - 2015
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/39381
SN  - 0278-7407
SN  - 1944-9194
VL  - 34
IS  - 1
SP  - 116
EP  - 132
PB  - American Geophysical Union
CY  - Washington
ER  -