Sponsored research projects

Detrital zircon U–Pb geochronology has been widely used, in many cases as the only available method, to interpret provenance of crustal fragments (terranes) displaced from the site of their origin and incorporated into younger orogenic belts. However, analysis of zircon age spectra may carry a significant bias that may result in large uncertainties in paleogeographic reconstrutions and geodynamic models. The project examines the validity of using detrital zircon ages as paleogeographic indicators through the use of advanced statistical methods such as multi-dimensional scaling (MDS), which, in turn, will be tested against independent constraints from Hf–Nd isotope geochemistry and paleomagnetism. Based on the example of the Avalonian–Cadomian terranes, now dispersed within the Caledonian, Variscan, and Alpine–Carpathian–Balkans orogenic belts, the project is directed towards derivation of a general model of how detrital zircon ages potentially record terrane displacements along or away of continental margins.

Principal investigator: Jiří Žák

Co-leader: Martin Svojtka

Grantor: Czech Science Foundation 

Duration: 2023-01 to 2025-12

Grant number: 23-06708S

Compared to siliceous rock, the non-siliceous rock of European prehistory has received little attention to date. And yet, the materials of polished tools represent a pan-European topic fostering international discussion. The core of the project focuses on the Early and Middle Neolithic environment in central Europe The focus of the project also permits a retrospective look into the period of the Upper Mesolithic and the continuity of use of a key material – metabasites of the Jizerské hory. A methodology of accurate non-destructive mineralogical and geochemical analysis has already been developed for the needs of the project, and attention was paid to this method in recent years. The results of a number of analyses can be compared to existing ethnographic distribution models. The project’s subject offers possibilities for international multidisciplinary cooperation.

Principal investigator: Pavel Burgert

Co-leader: Václav Kachlík

Grantor: Czech Science Foundation 

Duration: 2023-01 to 2025-12

Grant number: 23-05334S

Mélanges are lithotectonic units exhibiting a chaotic block-in-matrix fabric and containing blocks of contrasting provenance and composition that form by sedimentary, diapiric, or tectonic processes and occur in a variety of tectonic settings. Yet, they are most typical for active plate margins and especially for the subduction-accretion complexes. The main motivation of the proposed project is to address some of the outstanding current problems of mélange geology: (1) exploring quantitative criteria to distinguish sedimentary, diapiric, and tectonic mélanges; (2) deciphering strain histories from the often composite finite mélange fabric; (3) mechanisms of formation of the the so-called OPS mélanges, which form by disruption of Ocean Plate Stratigraphy (OPS) within accretionary wedges; (4) reconstructing material displacement paths within accretionary wedges during mélange formation; and, finally (5) interpreting the relationships between mélange types and their fabrics and subduction zone parameters such as slab dip, convergence angle and velocity. These issues will be thoroughly investigated via a multidisciplinary approach involving a combination of field work with analog experiments and quantitative methods (image analysis and anisotropy of magnetic susceptibility; AMS). For the purpose of the project, the Vardar suture zone in Serbia was selected as a world-class “natural laboratory” as it superbly exposes a wide range of mélange types in various structural positions.

Principal investigator: Tatiana Tkáčiková

Grantor: Charles University Grant Agency 

Duration: 2023-01 to 2025-12

Grant number: 260923