Lithosphere dynamics and orogenic plateau building in the northern Arabia-Eurasia collision zone

• Applicant: Dr. Renas Koshnaw
• Subject Area: Geology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 543912555

The Plate Tectonics theory effectively explains orogenic wedge formation at convergent margins, yet the origin of orogenic plateaus far from plate boundaries remains a contentious topic. Slab breakoff is a fundamental process that has been associated with the development of collisional orogenic wedges and plateaus. Slab breakoff, the complete detachment of the oceanic slab from the continental slab, is invoked to justify magmatism, exhumation of deep-seated rocks, and enhanced surface uplift in orogenic belts. However, this concept is often hypothesized for complex orogenic belts, based on limited observations, and challenged by contradicting tomographic images at different orogenic belts. Along the Alpine, Zagros, and Himalaya orogens, the Zagros orogen, due to being a young and less deformed orogen, is a key area. This research focuses on the continental collision zone of Arabia and Eurasia in the NW Zagros orogenic belt of the Kurdistan region of Iraq, which shows along–strike geologic and geodynamic variation. In this proposed research, I hypothesize that in the late Miocene, beneath the northern Arabia-Eurasia suture zone, the Neotethys oceanic slab experienced lateral tearing from the NW to the SE. This tearing occurred simultaneously with the northward movement of the Afar hot mantle material above the detached slab segment. I will investigate whether the evolution of the Arabian-Eurasian suture zone supports the hypothesis, which predicts (i) rapid regional uplift of the suture zone following prolonged subsidence as a result of slab detachment, or (ii) persistent subsidence of the lower plate, arguing against slab detachment. Fieldwork will be conducted in the NW Zagros belt to obtain stratigraphic and structural data as well as granitic, siliciclastic, and marine carbonate rock samples for thermochronologic, geochronologic, and isotopic analyses. Results will be integrated with existing tomographic images in the broader northern Middle East to evaluate the conclusion.

• DFG Programme: Research Grants
• International Connection: Iraq
• Co-Investigators: Dr. István Dunkl; Professor Dr. Jonas Kley; Professorin Dr. Taylor F. Schildgen, Ph.D.
• Cooperation Partner: Dr. Idrees Ahmed