Kinematic history of a reactivated oceanic suture: the Mamonia Complex Suture Zone, SW Cyprus

The Mamonia Complex Suture Zone in SW Cyprus marks an arcuate tectonic suture between an Upper Cretaceous, oceanic microplate of supra-subduction zone origin (Troodos Complex) and a deformed Triassic passive margin sequence (Mamonia Complex). Mapping of the serpentinite-filled fault zones that define the suture zone, combined with microstructural studies of its constituent fault rocks, has revealed evidence of three main tectonic events of Upper Cretaceous age: (1) high temperature (c. 600 degreesC), transform-related, dextral strike-slip and localized metamorphism of Mamonia Complex units (c. 90-83 Ma); (2) retrograde hydration (<400C) during dextral transtension associated with the rotation of the Troodos microplate and the shallow-level emplacement of serpentinite (c. 83-73 Ma); (3) regional contractional reactivation at low temperatures, which ceased by the latest Maastrichtian (c. 65 Ma). The present day structural geometries are interpreted as the result of Maastrichtian contractional reactivation of a pre-existing, steep and irregular structural architecture that formed during transtension. The resultant orientation of finite strain axes and thrust displacements display a radial distribution, documenting near fault normal contraction along the whole length of the arcuate suture zone. This pattern of displacements suggests a model whereby the Troodos microplate impinged on the Mamonia Complex during westerly- to southwesterly-directed plate motion, contractionally reactivating the mechanically weak suture zone.