Ondrejka, M. Uher, P., Pršek, J., Ozdín, D. 2007: Arsenian monazite-(Ce) and xenotime-(Y), REE arsenates and carbonates from the Tisovec-Rejkovo rhyolite, WesternCarpathians, Slovakia: Composition and substitutions in the (REE,Y)XO4 system (X = P, As, Si, Nb, S), Lithos. - Vol. 95, No. 1-2, 116-129.

Ondrejka, M., Uher, P., Putiš, M., Broska, I., Bačík, P., Konečný, P., Schmiedt, I., 2012: Two-stage breakdown of monazite by post-magmatic and metamorphic fluids: An example from the Veporic orthogneiss, Western Carpathians, Slovakia. Lithos 142-143, 245-255.

Uher P., Ondrejka M., Bačík P., Broska I., Konecny P. 2015: Britholite, monazite, REE carbonates, and calcite: Products of hydrothermal alteration of allanite and apatite in A-type granite from Stupné, Western Carpathians, Slovakia, Lithos, 236-237, 221-225.

Ondrejka M., Uher P., Ferenc Š., Milovská S., Mikuš T., Molnárová A., Škoda R., Kopáčik R., Bačík P. (2023) Gadolinium-dominant monazite and xenotime selective hydrothermal enrichment of middle REE during low-temperature alteration of uraninite, brannerite, and fluorapatite (the Zimná Voda REE-U-Au quartz vein, Western Carpathians, Slovakia). American Mineralogist, 108, 4, 754-768.

Ondrejka M., Uher P., Ferenc Š., Majzlan J., Pollok K., Mikuš T., Milovská S., Molnárová A., Škoda R., Kopáčik R., Kurylo S., Bačík P. (2023) Monazite-(Gd), a new Gd-dominant mineral of the monazite group from the Zimná Voda REE-U-Au quartz vein, Prakovce, Western Carpathians, Slovakia. Mineralogical Magazine, 87, 4, 568-574.

Ondrejka, M., Uher, P., Putiš, M., Kohút, M.,Broska, I., Larionov, A., Bojar, A-V., Sobocký, T. 2021: Permian A-type granites of the Western Carpathians and Transdanubian regions: Products of the Pangea supercontinent breakup. International Journal of Earth Sciences, 110, 2133-2155.

Ondrejka M., Molnárová A., Putiš M., Bačík P., Uher P., Voleková B., Milovská S., Mikuš T., Pukančík L. (2022) Hellandite-(Y)–hingganite-(Y)–fluorapatite retrograde coronae a novel type of fluid-induced dissolution–reprecipitation breakdown of xenotime-(Y) in the metagranites of Fabova Hoľa, Western Carpathians, Slovakia. Mineralogical Magazine, 86, 4, 586-605.

Ondrejka M., Uher P., Ferenc Š., Milovská S., Mikuš T., Molnárová A., Škoda R., Kopáčik R., Bačík P. (2023) Gadolinium-dominant monazite and xenotime selective hydrothermal enrichment of middle REE during low-temperature alteration of uraninite, brannerite, and fluorapatite (the Zimná Voda REE-U-Au quartz vein, Western Carpathians, Slovakia). American Mineralogist, 108, 4, 754-768.

Ondrejka M., Ferenc Š., Majzlan J., Števko M., Kopáčik R., Voleková B., Milovská S., Gottlicher J., Steininger R., Mikuš T., Uher P. Biroň A., Sejkora J., Molnárová A. (2023) Secondary uranyl arsenates–phosphates and Sb–Bi-rich minerals of the segnitite–philipsbornite series in the oxidation zone at the Prakovce-Zimná Voda REE–U–Au quartz-vein mineralisation, Western Carpathians, Slovakia. Mineralogical Magazine, 87, 6, 849-865.

Ondrejka M., Bačík, P., Majzlan J., Uher, P., Ferenc, Š., Mikuš, T., Števko M., Čaplovičová, M., Milovská S., Molnárová, A., Rößler, Ch., Matthes, Ch. (2024): Xenotime-(Gd), a new Gd-dominant mineral of the xenotime group from the Zimná Voda REE–U–Au quartz vein, Prakovce, Western Carpathians, Slovakia. Mineralogical Magazine 88, 5, 613-622.

Ondrejka, M. Uher, P., Pršek, J., Ozdín, D. 2007: Arsenian monazite-(Ce) and xenotime-(Y), REE arsenates and carbonates from the Tisovec-Rejkovo rhyolite, WesternCarpathians, Slovakia: Composition and substitutions in the (REE,Y)XO4 system (X = P, As, Si, Nb, S), Lithos. - Vol. 95, No. 1-2, 116-129 in Vereshchangin et al. 2019: Gasparite-(La), La(AsO4), a new mineral from Mn ores of the Ushkatyn-III deposit, Central Kazakhstan, and metamorphic rocks of the Wanni glacier, Switzerland, American Mineralogist 104, 10, 1469-1480

Ondrejka, M. Uher, P., Pršek, J., Ozdín, D. 2007: Arsenian monazite-(Ce) and xenotime-(Y), REE arsenates and carbonates from the Tisovec-Rejkovo rhyolite, WesternCarpathians, Slovakia: Composition and substitutions in the (REE,Y)XO4 system (X = P, As, Si, Nb, S), Lithos. - Vol. 95, No. 1-2, 116-129 in Nikolenko et al. 2018: The origin of magnetite-apatite rocks of Mushgai-Khudag Complex, South Mongolia: mineral chemistry and studies of melt and fluid inclusions, Lithos, 320-321, 567-582

Ondrejka, M. Uher, P., Pršek, J., Ozdín, D. 2007: Arsenian monazite-(Ce) and xenotime-(Y), REE arsenates and carbonates from the Tisovec-Rejkovo rhyolite, WesternCarpathians, Slovakia: Composition and substitutions in the (REE,Y)XO4 system (X = P, As, Si, Nb, S), Lithos. - Vol. 95, No. 1-2, 116-129 in Hoshino et al. 2016: REE Mineralogy and Resources, Handbook on the Physics and Chemistry of Rare Earths, 49, pp. 129-291

Ondrejka M, Putiš M, Uher P, Schmiedt I, Pukančík L, Konečný P 2016: Fluid-driven destabilization of REE-bearing accessory minerals in the granitic orthogneisses of North Veporic basement (Western Carpathians, Slovakia). Mineralogy and Petrology, 110:561–580 in Engi 2017: Petrochronology Based on REE-Minerals: Monazite, Allanite, Xenotime, Apatite, Reviews in Mineralogy and Geochemistry, 83, 1, pp. 365-418

Uher P., Ondrejka M., Bacik P., Broska I., Konecny P. 2015: Britholite, monazite, REE carbonates, and calcite: Products of hydrothermal alteration of allanite and apatite in A-type granite from Stupné, Western Carpathians, Slovakia, Lithos, 236-237, 221-225 in Johannes Giebel et al. 2017: Multi-stage formation of REE minerals in the Palabora Carbonatite Complex, South Africa, American Mineralogist, 102, 6, 1218-1233

VEGA 1/0467/20 (2020-2022, / principal investigator Assoc. prof. Martin Ondrejka) Remobilisation and fractionation of rare lithophile elements under hydrothermal and supergene conditions.

In recent years, lithophiles have become an object of study by geologists and soil scientists. The established facts

of their fractionation/remobilisation under low-T and supergene conditions appear to be one of the latest major achievements. Understanding their low-T behaviour is a relevant task, since they are useful geochem. tools of geol. processes. Minerals are unstable in some fluid regime and breakdown products can be formed. Rock-fluid interaction is an important process responsible for reactivation/remobilization of lithophiles in low-T/supergene stage. Such fluids may be important agents in supergenesis and during weathering, capable of explaining metasomatism that may not be easily interpreted. This project will inspect remobilisation/fractionation of lithophiles under low-T/supegene conditions where some important geochem.-biochem. processes may have occurred. Describing it in detail is an essential step towards an understanding of the behaviour of such elements in near-surface conditions.

APVV-19-0065 (2020-2023, principal investigator Prof. Marián Putiš, co-investigator Assoc. prof. Martin Ondrejka) Petrological-geochronological record of riftogenesis and crust-mantle recycling in the Western Carpathians orogenic wedge".

Specific groups of rocks and their minerals are searched as indicators of the riftogenic zones, despite they often have signatures of superimposed tectono-thermal overprinting from their incorporation into the orogenic zones. Mineralogicalpetrological (EPMA, micro-Raman, LA-ICP-MS, XRF, ICP-MS), isotopic-geochemical (LA-MC-ICP-MS, TIMS) andgeochronological (U-Pb SIMS, LA-ICP-MS, Ar-Ar, K-Ar) methods will be applied to establish the chemical composition of minerals and rocks, their isotopic characteristics (U-Pb, Pb-Pb, Sm-Nd, Rb-Sr, Zr-Hf, Re-Os) and the ages.

2016YFE0203000 (2017-2020; principal investigator Prof. Dr. Qiu-Li Li; co-investigator for Slovakia: Doc. Martin Ondrejka) "Cooperative research of microbeam analytical techniques of rock and minerals". Strategic international cooperation for technology Innovation” of National Key Research and Development Plan. The China Ministry of Science and Technology Project between the Institute of Geology and Geophysics of the Chinese Academy of Sciences in Beijing and Comenius University in Bratislava, Slovakia. Project deals with the development of methodics for isotopic dating of zircon, rutile and other phases by U-Pb SIMS, nano-SIMS and LA-ICP-MS at the Institute of Geology and Geophysics of the Chinese Academy of Sciences in Beijing and Wuhan University. We dated protolith and metamorphic ages of eclogites from the Veporic Superunit of the Western Carpathians and the Upper Austroalpine Unit of the Eastern Alps (Putiš et al., 2017, 2018, 2019). Application of nano-SIMS was successful at the dating of very fine-grained zircon (<100 µm) from volcanics and metavolcanics (Putiš et al., 2016; Ondrejka et al., 2018). This method also revealed an unknown Anisian magmatic zircon source the detrital zircon of which appeared in deep-water oceanic Meliatic sediments (Putiš et al., 2019). Newly-developed methodics for rutile dating was successfully aplied at the dating of metamorphic rutile from Veporicum and Meliaticum of the Western Carpathians, as well as rutile from eclogites of the Eastern Alps (Sieggraben and Kreuzeck ares; unpublished data). These are the first rutile datings in these regions, which provide the first rutile datings in the world.

APVV-15-0050 (2016-2019, principal investigator Prof. Marián Putiš, co-investigator Assoc. prof. Martin Ondrejka) Interaction models of crustal and mantle rocks with fluids in accretionary wedges of the Western Carpathians, eastern Alps and northern Turkey; correlation of P-T-X-t parameters.

The project investigated the fluid-driven alteration processes in crust-mantle prism rocks exposed in Alpidic orogene of the Western Carpathians, Eastern Alps and northern Turkey. We focused on fluid-rock interaction zones, the genesis of which had not yet been investigated: i) in subduction-accretionary wedges blueschists, eclogites and metaultramafics, ii) in lower crust orthogneisses, granites, metabasites and metaultramafics, iii) in skarns and iv) in lamprophyres and mantle xenoliths. These processes represent a fluid-rock interaction at the different lithosphere levels. Modern microscopic, electron-optic, rtg diffraction and spectroscopic methods were used for determination of the alteration zones mineral and rock chemical compositions. Thermodynamic modelling and geothermobarometry were applied for the estimation of the alteration reactions P-T-X conditions. Fluid-ultramafic rock interaction model was proposed, and the age of this process was established by the U-Pb SIMS and LA-ICP-MS dating of perovskite as a product of this interaction.

APVV-22-0092 (2022-2026, principal investigator Assoc prof. Martin Ondrejka) Petrogenetic models of Palaeozoic granitic rocks in the Western Carpathians and their correlation.

The project is focused on the geodynamic setting of Paleozoic granitic magmatism in the Western Carpathians as well as their correlation with analogous plutonic rocks across Variscan Europe, and updating the current petrogenetic models. The West-Carpathian Paleozoic granitic rocks represent a heterogeneous suite, which includes Early Paleozoic pre-Variscan (Cambrian-Ordovician), Variscan (Early Carboniferous), and post-Variscan (Permian) igneous lithotypes. The oldest group is related to an active Gonwana margin, and this transformed to Variscan orthogneisses. Relatively older Variscan granitoid plutons (ca. 365-350 Ma) may have formed in an extensional arc-type setting above an early Variscan (Lower Devonian) subduction zone. The following post-collision extension generated a younger group of the Variscan granites to tonalites (ca. 350-340, less 330 Ma). Both groups are consistent with the two anatectic events so far recognized at ca. 370-360 Ma and 350-340 Ma, respectively. Only minor part is formed in a post-collisional-extensional tectonic regime consistent with breakup of the Pangea supercontinent (mainly A- and specialized S-types, at ca. 280-250 Ma). Granitic rocks will be preferably studied by using the standard magmatic and metamorphic petrology methods namely: mineralogy, geochemistry and petrochronology (EPMA, microRaman, LA-ICP-MS, ICP-MS, XRF, Sm, Nd and Pb isotopes by TIMS, U-Th-Pb dating, modelling in Melts and Perple_X softwares). The main goals of the project include constraining the magmatic environments and melting protoliths of the granites, P-T-X conditions, the magmatic and subsolidus evolution ages, and their relationship to adjacent metamorphic rocks. Mineralogical study includes their metallogenetic potential. Towards a better understanding of granite petrogenesis, a general evolutionary model of the West-Carpathian Palaeozoic granitic magmatism in frame of wider European area is expected.