https://tektonika.online/index.php/home <h1><strong>\\ Write it. Share it. Read it. Free it!</strong></h1> <p><strong>τeκτoniκa</strong> is a community-led Diamond Open Access journal publishing peer-reviewed research in structural geology and tectonics. </p> <p>We offer an <strong>alternative</strong> to traditional publishing models, which hide scholarly work behind exclusive and expensive paywalls. Along with <strong>preprint platforms</strong>, <strong>data and software repositories, and sibling Diamond Open Access journals</strong>, τeκτoniκa is part of an expanding movement within academia focused on breaking the barriers inherited from the pre-internet publishing era, to ensure <strong>free and open access to knowledge for all</strong>.</p> <ul> <li>Thinking of submitting an article?</li> <li>Interested in reviewing for us?</li> <li>Keen to find out about new research being published?</li> <li>Curious about vacancies in the Tek-Team?</li> </ul> <p>Sounds like it's time you <strong><a href="https://tektonika.online/index.php/home/user/register">REGISTER</a></strong> ...</p> Aberdeen University en-US τeκτoniκa 2976-548X https://tektonika.online/index.php/home/article/view/127 <p>The recognition of crystalline basement nappes in deeply eroded orogens, which is critical to elucidating the tectonic and geodynamic histories of cratonic terranes, relies on the identification of key geometric and kinematic structural elements. These include (i) synformal anticlines and/or antiformal synclines along the nappe’s overturned lower limb; (ii) parasitic folds with thinned long limbs elongated parallel to transport direction; and (iii) a stretching lineation that records the nappe transport direction and which is coeval with and perpendicular to a fold axis-parallel lineation. The structure, stratigraphy and geophysics of the Isortoq Fault Zone (IFZ) and nearby supracrustal Isortoq and Eqe Bay belts (Rae craton, northern Baffin Island) suggest the occurrence of a regional synformal anticline interpreted as part of the lower limb of a Paleoproterozoic southeast-verging nappe. The northern northeast-striking, moderately southeast-dipping Isortoq belt is structurally thinned, metamorphosed to upper amphibolite to granulite facies, sheared (by the top-to-the-southeast IFZ) and overturned, with strata younging down-section to the northwest. In contrast, the southern east-northeast-striking, steeply southeast-dipping Eqe Bay belt is structurally thickened, comparatively less metamorphosed and less deformed, and stratigraphically youngs to the southeast. The geometry and orientation of the belts mirror those of mesoscale parasitic S- and Z-folds exhibiting thinned elongated limbs and thickened short limbs. The IFZ and associated faults represent a brittle-ductile shear zone formed at the base of the nappe during propagation; offsets along these faults are responsible for the distribution of isograds. The Isortoq nappe occurs along strike (and may be genetically associated) with southwest-verging Rinkian nappes exposed &gt;200 km to the northeast. South-verging fold nappes developed along the southern margin of the Rae craton contrast with north-verging, thin-skinned thrust sheets of the Foxe fold belt to the south, emphasizing the complex kinematics of the assembly of the Nuna supercontinent.</p> Benoit Saumur Stephen Johnston Diane Skipton Marc St-Onge Copyright (c) 2026 Benoit M Saumur, Stephen T Johnston, Diane R Skipton, Marc R St-Onge https://creativecommons.org/licenses/by/4.0 2026-10-21 2026-10-21 4 2 1 18 10.55575/tektonika2026.4.2.127 https://tektonika.online/index.php/home/article/view/111 <p class="p1">The subduction of an oceanic plate causes deformation of the overriding plate, from the forearc to the back-arc regions. Over the years, to address the physical controls on such deformation, various compilations on active deformation have been made, mixing various types of datasets including fault-slip rates, focal mechanisms and geodetic motions. The growing amount of available data now allows for the construction of consistent compilations in terms of data types. Here, we present a database for the kinematics of subduction zones which includes that of the overriding-plate deformation, consistently based on geodetic data. The database describes the 2-D (trench-normal and trench-parallel) motions of arc blocks for ~90% of active subduction zones, through the magnitude <em>v_d</em> and the deformation-obliquity angle (<em>O_vd</em>) between the blocks and the upper plate (undeformed interior of the overriding plate). We classify subduction zones into four dominant strain classes (compressional, strike-slip, extensional, and neutral), and into up to eight classes including intermediate regimes. Focusing on the strike-slip strain class, we show that a non-negligible trench-parallel motion is a widespread feature of active subduction zones. The convergence obliquity exerts, however, a contrasting effect on <em>O_vd</em>, thereby suggesting a limited effect on strain partitioning at oblique subduction zones. On the other hand, <em>O_vd</em> shows a positive correlation with slab dip, where low and high values are both associated with compressional and extensional classes, respectively. Finally, we provide revised estimates of subduction rates, allowing, for instance, refined estimates of the thermal parameter, which will permit future comparative investigations on subduction dynamics and tectonics.</p> Nestor Cerpa Serge Lallemand Arnauld Heuret Copyright (c) 2026 Nestor Cerpa, Serge Lallemand, Arnauld Heuret https://creativecommons.org/licenses/by/4.0 2026-10-29 2026-10-29 4 2 19 45 10.55575/tektonika2026.4.2.111