Structural Geology and Tectonics of the Zagros Fold-Thrust Belt

The Zagros Fold-Thrust Belt stretches over 1,500 km along the margin of the Arabian Plate, recording the collision with Eurasia since the late Eocene. Its architecture comprises a foreland basin, an imbricate thrust belt underlain by multiple detachment horizons and an hinterland domain of basement-involved deformation. Thin-skinned thrust sheets propagate above the core Hormuz salt, generating a series of fault-bend anticlines in the Simply Folded Belt. Further to the northeast, thick-skinned structures root into basement arches and reactivated Precambrian to Paleozoic faults, forming the Lurestan Arc and the High Zagros domain. Flexural modelling of sedimentary subsidence reveals a migrating bulge and foreland basin evolution, while magnetostratigraphy constrains the onset of collision near 27 Ma. Lithologic contrasts such as salt and mudrock detachments govern the depth extent of slip and fold wavelength. The region regularly produces moderate to large earthquakes on both basement faults and cover detachments, making it a natural laboratory for studying fold-thrust kinematics, detachment mechanics and seismic hazard. Hydrocarbon reservoirs within the Asmari and Pabdeh formations are shaped by folding and fracture networks, linking tectonic evolution to resource distribution. This belt thus illuminates fundamental processes in collisional orogens and bears direct societal relevance through seismic risk and energy exploration.

Research from Nature Portfolio

Recent studies have refined estimates of rupture processes for major Zagros earthquakes using time-domain P-wave displacement modelling. Analysis of strong-motion data for the 2017 Mw 7.3 Ezgeleh event reveals a near-constant stress drop of around 1 MPa across ruptures up to 16 km radius, with self-similar scaling between moment and rupture dimensions. Modelling accounts for anelastic attenuation to retrieve corrected moment-rate functions, yielding more accurate source radii, average slip and rupture durations. These insights improve understanding of fault mechanics under heterogeneous crustal conditions and inform seismic hazard assessments in fold-thrust settings.

Structural Geology and Tectonics of the Zagros Fold-Thrust Belt publication trend

The graph below shows the total number of articles in structural geology and tectonics of the zagros fold-thrust belt across all publications each year (not limited to Nature Index journals).

Technical terms

Fold-thrust belt: A tectonic regime where strata are folded and thrust-faulted due to convergent compression.

Thin-skinned tectonics: Deformation confined to sedimentary cover above a basal detachment, with minimal basement involvement.

Thick-skinned tectonics: Deformation that involves basement rocks and deep-seated faults.

Detachment horizon: A mechanically weak layer, such as evaporites or mudrocks, along which overlying strata detach and slide.

Foreland basin: A sedimentary basin adjacent to an orogenic belt formed by lithospheric flexure under tectonic load.

InSAR: Interferometric Synthetic Aperture Radar, a satellite-based technique for measuring ground deformation.

Coulomb stress transfer: A calculation of how stress changes on one fault affect the likelihood of slip on neighbouring faults.

References

1. Earthquake source parameters in Zagros region (Iran) from the time-evolutive P-wave displacement. Scientific Reports (2023).
2. Contemporaneous Thick- and Thin-Skinned Seismotectonics in the External Zagros: The Case of the 2021 Fin Doublet, Iran. Remote Sensing (2023).
3. Early Neogene foreland of the Zagros, implications for the initial closure of the Neo-Tethys and kinematics of crustal shortening. Earth and Planetary Science Letters (2017).
4. Logarithmic Model Joint Inversion Method for Coseismic and Postseismic Slip: Application to the 2017 Mw 7.3 Sarpol Zahāb Earthquake, Iran. Journal of Geophysical Research: Solid Earth (2019).