Article
Geosciences, Multidisciplinary
Stephen Collett, Karel Schulmann, Pierig Deiller, Pavla Stipska, Vit Peresty, Marc Ulrich, Yingde Jiang, Luc de Hoym de Marien, Jitka Mikova
Summary: This article investigates the high-pressure and high-temperature metamorphism during the Mid-Devonian period in the Variscan Orogeny, focusing on the geological characteristics of the Marianske Lazne Complex (MLC). The unique position of MLC at the base of its original upper plate is highlighted. The study reveals that both MLC and the upper plate developed above a relatively unaltered Neoproterozoic lithospheric mantle, which is important for reconstructing the original architecture of the Variscan terranes.
GEOSCIENCE FRONTIERS
(2022)
Article
Geosciences, Multidisciplinary
Lukas Krmicek, Milan Novak, Robert B. Trumbull, Jan Cempirek, Stanislav Houzar
Summary: Various metacarbonate and calc-silicate rocks in the Bohemian Massif of the Variscan orogen contain tourmaline in different paragenetic settings, each showing distinctive compositional features. The presence of tourmaline with different B-isotope compositions in specific units suggests regional variations and possible metamorphic processes within the studied areas.
GEOSCIENCE FRONTIERS
(2021)
Review
Geosciences, Multidisciplinary
Wolfgang Franke, Andrzej Zelazniewicz
Summary: The Variscan Bohemian Massif provides evidence for two oceans and records various geological processes such as rifting, drift, convergence, and collision. It also confirms the emplacement and cooling of high-grade rocks from the asthenospheric mantle. The interaction between different tectonic units and the controversy surrounding the tectonic paths in the region are discussed.
Article
Geochemistry & Geophysics
Jiri Kvapil, Jaroslava Plomerova, Hana Kampfova Exnerova, Vladislav Babuska, Gyoergy Hetenyi
Summary: The study presents a regional-scale model of velocity distribution in the crust of the Bohemian Massif, revealing significant velocity variations between different geological units, especially remnants of tectonic activities from the Variscan period.
Correction
Geosciences, Multidisciplinary
Vojtech Janousek, Pavel Hanzl, Martin Svojtka, John M. Hora, Yulia V. Erban Kochergina, Petr Gadas, Frantisek V. Holub, Axel Gerdes, Krystof Verner, Kristyna Hrdlickova, J. Stephen Daly, David Burianek
Summary: The authors apologize for inadvertently providing an erroneous version of the recalculated titanite analyses data table.
INTERNATIONAL JOURNAL OF EARTH SCIENCES
(2021)
Article
Geochemistry & Geophysics
Johannes E. Pohlner, Afife El Korh, Reiner Klemd, Bernard Grobety, Thomas Pettke, Massimo Chiaradia
Summary: Eclogites, metagabbros, and paragneisses in the Variscan Munchberg Massif underwent a complex succession of igneous, hydrothermal, and metamorphic processes, with geochemical signatures revealing a varied history. The light and dark eclogites were likely formed from different parental magmas, with the former interpreted as plagioclase-rich cumulates and the latter as complementary differentiates. Metagabbros showed an enriched trace element signature and origin from a more enriched mantle source than the eclogites. The rocks experienced limited metamorphic fluid-rock interactions, possibly due to the lack of lawsonite dehydration.
Article
Geosciences, Multidisciplinary
Matej Machek, Igor Soejono, Jiri Slama, Eliska Zackova
Summary: The high-grade metamorphic complexes along the northern Moldanubian periphery of the central Bohemian Massif provide a detailed structural record of the collisional evolution of the Variscan Orogeny. Multiple tectonic events were identified through the analysis of rock structures and microstructures, as well as geochronology.
JOURNAL OF THE GEOLOGICAL SOCIETY
(2022)
Article
Geochemistry & Geophysics
Oscar Laurent, Simon Couzinie, Luc S. Doucet
Summary: The study reveals the timescales of lower crustal ultra-high temperature metamorphism and the production and transfer of granitic magmas. Zircon petrochronology of felsic and mafic granulite xenoliths from the Variscan eastern French Massif Central shows that these rocks underwent Variscan UHT peak metamorphism at 940-970°C and 8±2 kbar. The zircon U-Pb dates of the felsic granulites range from -315 to -265 Ma, indicating continuous crystallization of zircon upon cooling from the thermal peak. The emplacement of upper crustal granite started at 340 Ma and peaked at 313±3 Ma, reflecting melt extraction along the prograde path of the lower crust. The crystallization ages of mid-crustal migmatites (315-300 Ma) and lower crustal granulites (315-265 Ma) suggest slow cooling in the presence of melt.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geology
Ondrej Barta, Rostislav Melichar, Jan Cerny
Summary: The tectonic development of the Variscan belt in Central Europe involved both compression and extensional phases related to gravitational collapse, resulting in the formation of sedimentary basins and magmatic bodies. The Benesov pluton, for example, exhibited primary magmatic fabrics and deformational fabrics indicating extensional stages. The study revealed a three-stage extensional history during the gravitational collapse, highlighting the complex succession of individual extensional stages rather than a simple process.
ANNALES SOCIETATIS GEOLOGORUM POLONIAE
(2021)
Article
Geology
Jochen Roetzler, Martin J. Timmerman
Summary: The Saxon Granulite Massif is a key area for understanding the Palaeozoic Variscan orogeny, with a dome structure comprising high-P granulites and low-P metasedimentary rocks. New age and petrologic data suggest that the metaophiolites developed from early Cambrian protoliths and underwent high-P amphibolite facies metamorphism in the mid- to late-Devonian, followed by thermal overprinting by the exhuming hot granulite body in the early Carboniferous. The exhumation and cooling rates of the granulite body are estimated to be around 8 mm/year and 80 degrees C/Ma, with a significant drop in exhumation rate and a slight rise in cooling rate during the different stages of exhumation.
JOURNAL OF METAMORPHIC GEOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Stephen Collett, Pavla Stipska, Karel Schulmann, Jitka Mikova, Alfred Kroener
Summary: The study of the Velke Vrbno Dome eclogite provides evidence for the emplacement of eclogite protoliths in a transitional supra-subduction to continental-rift setting. Additionally, the discovery of a fragment of Palaeoproterozoic basement in the region suggests an earlier geological history.
JOURNAL OF THE GEOLOGICAL SOCIETY
(2021)
Article
Geochemistry & Geophysics
He-Zhi Ma, Yi-Xiang Chen, Kun Zhou, Peng Gao, Yong-Fei Zheng, Xiang-Ping Zha, Xiao-Ping Xia, Zi-Fu Zhao, Fang Huang
Summary: The study of syn-exhumation granites in the Sulu ultrahigh-pressure metamorphic belt in east-central China revealed large-scale partial melting of deeply subducted continental crust in the terminal stage of continental collision during the Triassic period. The geochemical composition and zircon ages of the granites provide insights into their origin and evolution, showing significant differentiation mainly through fractional crystallization during magma evolution.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geochemistry & Geophysics
Jakub Kryl, Petr Jerabek, Ondrej Lexa
Summary: The study of the Erzgebirge dome reveals different microstructural types associated with continuous deformation and decompression processes, shedding light on the formation mechanism of the orogenic wedge.
Article
Geochemistry & Geophysics
Hans-Joachim Massonne, Botao Li
Summary: The study examined the pressure-temperature path of eclogite from Les Essarts high-pressure unit in western France and identified unusual atoll garnet. Through mineral chemistry characterization and thermodynamic modeling, the metamorphic evolution of eclogite was revealed. A geodynamic scenario was outlined to explain the formation and evolution of eclogite in two different geotectonic environments.
Article
Geology
Marine Jouvent, Ondrej Lexa, Vit Peresty, Petr Jerabek
Summary: The study focuses on the transition from low-grade phyllites to medium-grade micaschists in the surrounding metasediments, using thermodynamic modeling to determine the P-T conditions of four deformation fabric events. The evolution of Variscan orogenic processes from continental subduction to orogenic wedge formation is characterized by different metamorphic events with varying geothermal gradients. The Erzgebirge part of the Saxothuringian Domain displays an example of active margin evolution involving accretionary prism formation, orogenic wedge building through subducted continental crust accretion, and subsequent extensional collapse.
JOURNAL OF METAMORPHIC GEOLOGY
(2022)
Article
Geology
Jiri Zak, Martin Svojtka, Ianko Gerdjikov, Alexandre Kounov, Dian A. Vangelov
Summary: The study focuses on analyzing four lithotectonic units in the Balkans using detrital zircon U-Pb geochronology to understand their formation and origins. Through statistical comparison and multidimensional scaling, the Balkan terranes are compared with other terranes from the Eastern Alps to Iran, revealing their paleogeographic positions and significant dextral strike-slip displacements.
INTERNATIONAL GEOLOGY REVIEW
(2022)
Article
Geology
Fritz Finger, David Schiller, Martin Lindner, Christoph Hauzenberger, Krystof Verner, Jiri Zak
Summary: Comprehensive zircon thermometry was used to study the thermal evolution of the Variscan South Bohemian batholith and the emplacement temperature of its granitic rocks. The study found that the early stages of batholith formation were characterized by low to medium temperature melting driven by isothermal exhuma-tion, while later stages saw the intrusion of high to ultrahigh temperature granites, possibly linked to a hidden mafic intrusion.
Article
Geosciences, Multidisciplinary
Reza Syahputra, Jiri Zak, R. Damian Nance
Summary: The diachronous opening of the Rheic Ocean and the separation of Avalonian-Cadomian terranes from Gondwana during the late Ediacaran to early Cambrian period remains poorly understood. The Pribram-Jince basin in the Bohemian Massif is studied as a case example to better understand Cambrian rifting. The study provides insights into the sources of sedimentary deposits and the tectonic evolution of the basin.
Article
Mathematics, Applied
Eliska Smidova, Petr Kabele, Michal Sejnoha
Summary: This paper presents a numerical analysis of the three-point bending test of glued-laminated timber arches with the fibers aligned with the longitudinal direction. The results demonstrate that the model can adequately simulate the quantitative response of the arches, including both linear and non-linear behavior, as well as capturing the most distinctive features of cracking.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2022)
Article
Geosciences, Multidisciplinary
Lukas Ackerman, Jiri Zak, Karel Zak, Jan Pasava, Vaclav Kachlik, John Hora, Frantisek Veselovsky, Jaroslava Hajna
Summary: The Ediacaran to early Cambrian limestones in the Blovice accretionary wedge demonstrate how paleooceanographic and palaeoenvironmental conditions at active plate margins can be recorded by isotopic composition. Different types of limestones provide insights into various depositional conditions and are linked with paleooceanic and paleogeographic interpretations. Additionally, carbonate-bearing silicate rocks with different elemental and isotopic compositions suggest their common origin at active margins and some of them may have formed through hydrothermal activity.
PRECAMBRIAN RESEARCH
(2022)
Article
Geosciences, Multidisciplinary
Lukas Ackerman, Jiri Zak, Vaclav Kachlik, Martin Svojtka, Filip Tomek, Vaclav Santolik, Jiri Slama, Jakub Trubac, Ladislav Strnad, Frantisek Vacek
Summary: This study presents new geochemical and geochronological data for different lithotectonic units in the northeastern part of the Superior Province in Canada, providing insights into crustal growth and tectonic regime during the late Archean. The results suggest a transition from plume-dominated to plate-tectonic regime, representing a significant crustal growth event.
PRECAMBRIAN RESEARCH
(2022)
Article
Engineering, Civil
Joaquim Barros, Beatriz Sanz, Petr Kabele, Rena C. Yu, Gunther Meschke, Jaime Planas, Vitor Cunha, Antonio Caggiano, Nilufer Ozyurt, Ventura Gouveria, Ab Van den Bos, Elisa Poveda, Erez Gal, Jan Cervenka, Gerrit E. Neu, Pierre Rossi, Daniel Dias-da-Costa, Peter K. Juhasz, David Cendon, Gonzalo Ruiz, Tiago Valente
Summary: Experimental research has shown that adding short fibers to cement-based materials can greatly improve the behavior of concrete structures under normal and extreme conditions. However, the current methods for evaluating predictive performance rely on simulating experimental tests, which may not be practical for structural design. Further analysis and understanding of the models and their parameters are needed to enhance their predictive capabilities.
Article
Engineering, Civil
Eliska Smidova, Petr Kabele, Michal Sejnoha
Summary: This study presents experimental results on solid and glued laminated timber made of European spruce, aiming to obtain consistent material parameters for calibration of a material model capable of capturing complex timber behavior for numerical simulations. The results provide insight into the mechanical properties and fracture behavior of timber.
ENGINEERING STRUCTURES
(2022)
Article
Geosciences, Multidisciplinary
Leta Megerssa, Krystof Verner, David Burianek, Ondrej Pour, Filip Tomek, David Schiller, Karel Martinek
Summary: This paper presents new structural, anisotropy of magnetic susceptibility (AMS), and petrological data in tandem with existing geochronological data to determine a polyphase Variscan tectonometamorphic event in the southwestern Moldanubian Zone of the Bohemian Massif. The study reveals the successive tectonometamorphic evolution of high-grade metamorphic rocks in this area, highlighting three main geodynamic episodes: collisional to exhumation, late-orogenic shortening, and late-orogenic extension.
INTERNATIONAL JOURNAL OF EARTH SCIENCES
(2023)
Article
Construction & Building Technology
Joaquim Barros, Beatriz Sanz, Marcilio Filho, Fabio Figueiredo, Petr Kabele, Rena C. C. Yu, Guenther Meschke, Jaime Planas, Vitor Cunha, Antonio Caggiano, Niluefer Ozyurt, Ventura Gouveia, Ab van den Bos, Elisa Poveda, Erez Gal, Jan Cervenka, Gerrit E. Neu, Pierre Rossi, Daniel Dias-da-Costa, Peter K. Juhasz, David Cendon, Gonzalo Ruiz, Tiago Valente
Summary: This article describes the second blind simulation competition (BSC) organized by the fib WG 2.4.1 for assessing the predictive performance of FEM-based models in the analysis and design of FRC structures. The chosen structural system, a hybrid FRC shallow beam supported on columns or piles, demonstrates the potential of FRC in such applications and evaluates the accuracy of computational models. The experimental results obtained from testing two shallow beams are presented, including applied loads, strain measurements, and crack widths, as well as the rules and outcomes of the competition.
STRUCTURAL CONCRETE
(2023)
Article
Geosciences, Multidisciplinary
Lukas Ackerman, Jiri Zak, Vaclav Kachlik, Jan Pasava, Karel Zak, Andreas Pack, Frantisek Veselovsky, Ladislav Strnad
Summary: The Blovice accretionary complex in the Bohemian Massif contains abundant chert bodies that were formed on an oceanic plate during subduction beneath the northern margin of Gondwana. The characteristics and formation processes of the cherts reveal diverse depositional environments and positions on the oceanic plate. These cherts record a complex interplay between seafloor-related volcanic and sedimentary processes, hydrothermal activity, and subduction processes.
GEOSCIENCE FRONTIERS
(2023)
Article
Geosciences, Multidisciplinary
Michael Somr, Jiri Zak, Petr Kabele, Filip Tomek
Summary: This study develops a general model predicting fracture development above inflating and deflating magma chambers using the finite element method. Through calculations of 11 representative cases, it is demonstrated that pressure evolution inside a magma chamber leads to various fracturing processes in the host rock. The modeling approach also describes the direction, mode, and orientation of ring fault initiation and growth.
EARTH-SCIENCE REVIEWS
(2023)
Article
Geology
Jiri Zak, Jiri Slama, Reza Syahputra, R. Damian Nance
Summary: The Bohemian Massif in Central Europe formed from lithospheric fragments at the northern margin of Gondwana. The key geodynamic process that shaped this margin was the Cambro-Ordovician rifting that opened the Rheic Ocean. The mechanism of this rifting is reconstructed based on new U-Pb zircon ages, and it is suggested that stretching of the lower lithosphere preceded upper lithospheric rifting, leading to the breakup of Gondwana.
INTERNATIONAL GEOLOGY REVIEW
(2023)
Article
Geochemistry & Geophysics
Tadeas Hajek, Krystof Verner, Vaclav Spillar, David Burianek, Kenneth Johnson
Summary: Late-orogenic granitoids provide unique evidence of post-collisional exhumation, including decompression melting and magma differentiation. The Weinsberg Type Granitoids (WTG) show geochemical signatures of partial melting of metasedimentary sequences and fractionation of K-feldspar, plagioclase, and biotite during magma ascent. The WTG textures indicate in-situ crystallization and crystal/melt separation, forming K-feldspar phenocryst-rich domains. The fabric patterns within the Kaplice Sheet suggest changes in regional stress conditions and buoyancy forces during magma ascent and emplacement.
