Kinematics of Late Cretaceous subduction initiation in the Neo‐Tethys Ocean reconstructed from ophiolites of Turkey, Cyprus, and Syria

Abstract

Formation of new subduction zones represents one of the cornerstones of plate tectonics, yet both the kinematics and geodynamics governing this process remain enigmatic. A major subduction initiation event occurred in the Late Cretaceous, within the Neo‐Tethys Ocean between Gondwana and Eurasia. Suprasubduction zone ophiolites (i.e., emerged fragments of ancient oceanic lithosphere formed at suprasubduction spreading centers) were generated during this subduction event and are today distributed in the eastern Mediterranean region along three ~E‐W trending ophiolitic belts. Several models have been proposed to explain the formation of these ophiolites and the evolution of the associated intra‐Neo‐Tethyan subduction zone. Here we present new paleospreading directions from six Upper Cretaceous ophiolites of Turkey, Cyprus, and Syria, calculated by using new and published paleomagnetic data from sheeted dyke complexes. Our results show that ~NNE‐SSW subduction zones were formed within the Neo‐Tethys during the Late Cretaceous, which we propose were part of a major step‐shaped subduction system composed of ~NNE‐SSW and ~WNW‐ESE segments. We infer that this subduction system developed within old (Triassic?) lithosphere, along fracture zones and perpendicular weakness zones, since the Neo‐Tethyan spreading ridge formed during Gondwana fragmentation would have already been subducted at the Pontides subduction zone by the Late Cretaceous. Our new results provide an alternative kinematic model of Cretaceous Neo‐Tethyan subduction initiation and call for future research on the mechanisms of subduction inception within old (and cold) lithosphere and the formation of metamorphic soles below suprasubduction zone ophiolites in the absence of nearby spreading ridges.

Breakup Without Borders: How Continents Speed Up and Slow Down During Rifting

“…Eocene plate motion change is contemporaneous with the initiation of major new intraoceanic subduction zones across a wide region of the western Pacific presently represented by the Izu-Bonin-Mariana and Tonga-Kermadec systems (Gurnis et al, 2004). The details of earlier subduction initiations are less clear, but mid-Cretaceous subduction initiation within the Tethys ocean (Guilmette et al, 2018;Maffione et al, 2017) could be connected to increases in rift velocity within the South Atlantic and between Australia and Antarctica. Our model results allow us to propose the far-field effect of rift acceleration and breakup in the North Atlantic and Eurasia Basin (∼55 Myr ago) as an alternative, plausible catalyst for distal, almost contemporaneous changes in plate boundary configuration and force balance.…”

The Dynamic History of 220 Million Years of Subduction Below Mexico: A Correlation Between Slab Geometry and Overriding Plate Deformation Based on Geology, Paleomagnetism, and Seismic Tomography

“…SSZ zone ophiolites, such as the Vizcaíno ophiolite, are widely interpreted to form in forearc settings during the subduction initiation process (e.g., Stern et al, ; Wakabayashi et al, ), or shortly thereafter, during the first stage of overriding plate extension following subduction initiation (van Hinsbergen, Peters, et al, ). They may form both in intraoceanic settings (e.g., Philippine Sea plate; Stern & Bloomer, ) or Neotethys (Dilek & Furnes, ; Maffione et al, ; Maffione & van Hinsbergen, ; Maffione, van Hinsbergen, et al, ; Moix et al, ), as well as along or close to continental margins (e.g., the Californian Coast Range Ophiolite; Metcalf & Shervais, ; Shervais et al, ; Wakabayashi, ), the Indus‐Yarlung ophiolites of Tibet (Huang et al, ; Maffione, Thieulot, et al, ; Pozzi et al, ), or the Izmir‐Ankara ophiolites of northern Turkey (Topuz, Çelık, et al, ; Topuz, Göçmengil, et al, ).…”

Microtextures and fluid inclusions from vein minerals hosted in the Pillow Lavas of the Troodos supra-subduction zone

“…A tectonic sketch explains formation and precipitation processes of the different studied vein types together with FI evolution in the proto-fore-arc setting of the N-S striking Troodos SSZ (Pearce et al, 1984;Maffione et al, 2017) exemplarily for the UPL (Fig. 8): Completely sealed syntaxial veins suffered fracturing and subsequent seawater infiltration accompanied by immediate mineral precipitation (crack and sealing process, Fig.…”