Archean supercontinents: myth or reality?
The concept of the supercontinent cycle has revolutionized our views on how the Earth works by linking mantle dynamics, plate tectonics, and mantle-derived melting. During the Archean Eon, however, the presence and nature of supercontinents has been under vigorous debate. Yet, proving the presence or absence of Archean supercontinents may provide details on the onset of the supercontinent cycle, modern-style plate tectonics and changes of supercontinental cycles through time. We will pursue a multi-technique study combining elemental and isotopic (Hf–Nd–Pb–Si–O) data with tectonic and structural observations obtained for selected late Archean cratons. The obtained data will be used to reveal presence of continental collisional settings that might be correlative among the cratons and thus, provide an evidence for the existence of supercontinent(s). The gathered interpretations will then serve as a basis to develop a general model identifying the major mechanisms that were responsible for the formation of supercontinents during the Archean Eon.
Principal investigator: Lukáš Ackerman
Co-leader: Jiří Žák
Grantor: Czech Science Foundation
Duration: 2025-01 to 2027-12
Grant number: 25-16420S
Budget: 341 000 EUR
Emplacement of the Ibar ophiolite: kinematics and internal deformation of ophiolite nappes in the Vardar zone
Ophiolites, i.e., allochthonous fragments of oceanic mantle and crustal rocks emplaced onto continental margin during plate convergence, have long been recognized as a key feature of plate tectonics. Despite decades of study, current models of ophiolite emplacement remain broadly generalized, with mostly plate-scale models available, which offer limited insight into the internal deformation mechanisms that control emplacement processes. Structural studies of ophiolites and their metamorphic soles demonstrate complex and heterogeneous deformation patterns that conventional 2D models cannot adequately explain. The motivation for this project aims to: (1) characterize the kinematics of ophiolite emplacement through detailed structural and microstructural analysis, (2) decipher the internal structural deformation of the ophiolite and its metamorphic sole during emplacement, and (3) evaluate the 3D geometry of emplacement, highlighting how natural 3D emplacement diverges from traditional 2D “textbook” models.
Principal investigator: Tatiana Tkáčiková
Grantor: Charles University Grant Agency
Duration: 2026-01 to 2027-12
Grant number: 629826
Budget: 17 300 EUR
Cross-laboratory exchange of rock-magnetic protocols: example of the Shetland ophiolite
The primary objective of this project is to enhance the efficiency and reliability of rock magnetic laboratory protocols and facilitate the exchange of methodological approaches through a joint field-based and laboratory study involving two leading rock magnetic laboratories: the Laboratory of Rock Magnetism at Charles University and the M2Ore Magnetics Lab at the University of St Andrews. This will be achieved through shared fieldwork, reciprocal use of instruments, comparative data analysis, and joint development of standardized measurement procedures. The case study will focus on the Shetland Ophiolite Complex, a well-exposed and structurally well-preserved fragment of oceanic lithosphere, which offers a natural laboratory for examining the relationships between plate-tectonic setting, deformation and emplacement mechanisms of oceanic floor fragments onto continental margins.
Principal investigator: Filip Tomek
Co-leader: William McCarthy (University of St Andrews)
Grantor: Charles University and University of St Andrews
Duration: 2025-09 to 2026-12
Budget: 6000 EUR
Completed projects
2023-2025 Metabasites of the Jizerské hory (Jizera Mountain) type as a trans-cultural link between Central European Prehistoric communities (funded by grant of the Czech Science Foundation No. 23-05334S to Pavel Burgert, co-leader Václav Kachlík)
2023-2025 Detrital zircon geochronology as a tool for interpreting terrane provenance (funded by grant of the Czech Science Foundation No. 23-06708S to Jiří Žák, co-leader Martin Svojtka)
2023-2025 Magnetic fabric of accretionary wedge mélanges: a new tool for interpreting subduction zone dynamics? (funded by grant of the Charles University Grant Agency No. 354821 to Tatiana Tkáčiková)
2020-2023 Caldera volcanism of the European Variscan belt: insights from structure and rock-magnetism (funded by grant of the Charles University Grant Agency No. 260923 to Petr Vitouš)
2020-2023 Cherts and carbonates as geochemical proxies of paleoenvironmental conditions and Ocean Plate Stratigraphy (funded by grant of the Czech Science Foundation No. 20-13644S to Lukáš Ackerman, co-leaders Jiří Žák and Jan Pašava)
2020-2022 The role of tectonic inheritance in continental rifting and basin inversion (funded by grant of the Charles University Grant Agency No. 952220 to Reza Syahputra)
2020-2022 Magnetic petrofabrics (AARM and AMS) as a tool for understanding of activity and evolution of calderas (funded by grant of the Charles University Grant Agency No. 124320 to Irena Olšanská)
2019–2022 Late Archean granites: markers of modern-style plate tectonics? (funded by grant of the Czech Science Foundation No. 19-08066S to Jiří Žák, co-leader Martin Svojtka)
2017–2019 Black shale formations as geochemical markers of paleoenvironmental changes and tectonic setting along active continental margins (funded by grant of the Czech Science Foundation No. 17-15700S to Lukáš Ackermann, co-leader Jiří Žák)
2016–2018 Sedimentary record and mechanics of collapse of orogenic belts (funded by grant of the Czech Science Foundation No. 16-11500S to Jiří Žák, co-leader Petr Kabele)
2014–2016 Dynamics of Precambrian accretionary wedges and mélanges (funded by grant of the Czech Science Foundation No. P210/14/10589P to Jaroslava Hajná)
2012–2014 Calderas as indicators of thermal-mechanical evolution of subvolcanic magma chambers (funded by grant of the Czech Science Foundation No. GAP210/12/1385 to Jiží Žák, co-leader Petr Kabele)