loading page

Tectono-stratigraphic evolution of the intermontane Tarom Basin (NW sectors of the Arabia-Eurasia collision zone): insights into the vertical growth of the Iranian Plateau margin
  • +5
  • Mohammad Paknia,
  • Paolo Ballato,
  • Massimo Mattei,
  • Mohammad R. Ghassemi,
  • Francesca Cifelli,
  • Jamshid Hassanzadeh,
  • Giovanni Vezzoli,
  • Majid Mirzaie Ataabadi
Mohammad Paknia
University of Roma Tre

Corresponding Author:[email protected]

Author Profile
Paolo Ballato
University of Roma Tre
Author Profile
Massimo Mattei
University of Roma Tre
Author Profile
Mohammad R. Ghassemi
Institute of Earth and Environmental Sciences, University of Potsdam, Potsdam, Germany, Institute for Earth Science ( Geological Survey of Iran)
Author Profile
Francesca Cifelli
University of Roma Tre
Author Profile
Jamshid Hassanzadeh
California Institute of Technology
Author Profile
Giovanni Vezzoli
Universita Milano-bicocca
Author Profile
Majid Mirzaie Ataabadi
University of Zanjan
Author Profile

Abstract

The intermontane Tarom Basin of NW Iran (Arabia-Eurasia collision zone) is located at the transition between the Iranian Plateau (IP) to the SW and the Alborz Mountains to the NE. This basin was filled by Late Cenozoic synorogenic red beds that retain first-order information on the erosional history of adjacent topography, the vertical growth of the plateau margin and its lateral (orogen perpendicular) expansion. Here, we perform a multidisciplinary study including magnetostratigraphy, sedimentology, geochronology and sandstone petrography on these red beds. Our data show that widespread Eocene arc volcanism in NW Iran terminated at ~ 38-36 Ma, while intrabasinal synorogenic sedimentation occurred between ~ 16.5 and < 7.6 Ma, implying that the red beds are stratigraphically equivalent to the Upper Red Formation. After 7.6 Ma, the basin experienced intrabasinal deformation, uplift and erosion in association with the establishment of external drainage. Fluvial connectivity with the Caspian Sea, however, was interrupted by at least four episodes of basin aggradation. During endorheic conditions the basin fill did not reach the elevation of the plateau interior and hence the Tarom Basin was never integrated into the plateau realm. Furthermore, our provenance data indicate that the northern margin of the basin experienced a greater magnitude of deformation and exhumation than the southern one (IP margin). This agrees with recent Moho depth estimates, suggesting that crustal shortening and thickening cannot be responsible for the vertical growth of the northern margin of the IP, and hence surface uplift must have been driven by deep-seated processes.