GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions

Date

2006

Authors

Reilinger, Robert
McClusky, Simon
Vernant, Philippe
Lawrence, Shawn
Ergintav, Semih
Cakmak, R.
Ozener, H.
Kadirov, Fakhraddin
Guliev, Ibrahim
Stepanyan, Ruben

Journal Title

Journal ISSN

Volume Title

Publisher

American Geophysical Union

Abstract

The GPS-derived velocity field (1988-2005) for the zone of interaction of the Arabian, African (Nubian, Somalian), and Eurasian plates indicates counterclockwise rotation of a broad area of the Earth's surface including the Arabian plate, adjacent parts of the Zagros and central Iran, Turkey, and the Aegean/Peloponnesus relative to Eurasia at rates in the range of 20-30 mm/yr. This relatively rapid motion occurs within the framework of the slow-moving (∼5 mm/yr relative motions) Eurasian, Nubian, and Somalian plates. The circulatory pattern of motion increases in rate toward the Hellenic trench system. We develop an elastic block model to constrain present-day plate motions (relative Euler vectors), regional deformation within the interplate zone, and slip rates for major faults. Substantial areas of continental lithosphere within the region of plate interaction show coherent motion with internal deformations below ∼1-2 mm/yr, including central and eastern Anatolia (Turkey), the Southwestern Aegean/Peloponnesus, the Lesser Caucasus, and Central Iran. Geodetic slip rates for major block-bounding structures are mostly comparable to geologic rates estimated for the most recent geological period (∼3-5 Myr). We find that the convergence of Arabia with Eurasia is accommodated in large part by lateral transport within the interior part of the collision zone and lithospheric shortening along the Caucasus and Zagros mountain belts around the periphery of the collision zone. In addition, we find that the principal boundary between the westerly moving Anatolian plate and Arabia (East Anatolian fault) is presently characterized by pure left-lateral strike slip with no fault-normal convergence. This implies that "extrusion" is not presently inducing westward motion of Anatolia. On the basis of the observed kinematics, we hypothesize that deformation in the Africa-Arabia-Eurasia collision zone is driven in large part by rollback of the subducting African lithosphere beneath the Hellenic and Cyprus trenches aided by slab pull on the southeastern side of the subducting Arabian plate along the Makran subduction zone. We further suggest that the separation of Arabia from Africa is a response to plate motions induced by active subduction.

Description

Keywords

Keywords: Arabian plate; collision zone; continental lithosphere; deformation; GPS; peripheral region; plate boundary; plate motion; plate tectonics; remote sensing; subduction zone; Africa; Anatolia; Arabian Peninsula; Asia; East Africa; Eurasia; Middle East; Soma

Citation

Source

Journal of Geophysical Research

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

Restricted until

2037-12-31