Geology and Re-Os molybdenite geochronology of the Kurišková U-Mo deposit (Western Carpathians, Slovakia)

Abstract

The Kurišková U-Mo deposit from the Gemeric Unit of the Western Carpathians (Slovakia) is an example of polygenic deposit whose origin involved several events: endogenous, related to magmatism/volcanism, and exogenous, associated with precipitation from meteoric hydrothermal fluids in repeated tectonically-driven (fold & thrust and shear zones) channel ways penetrating the Permian Huta volcano-sedimentary complex. Sources of the U-Mo mineralization were multiple: (a) molybdenite was derived directly from juvenile hydrothermal fluids related to igneous activity, (b) the U mineralization formed from meteoric fluids circulating through altered and metamorphosed basaltic and rhyolitic volcanics intercalated by clastic sediments (sandstones and mudrocks), which interacted in an arid to humid climate with organic and carbonate substances within Permian basin. The principal ore-forming minerals are uraninite, coffinite, molybdenite and apatite with rare orthobrannerite and powellite. Two basic mineralization forms are present: (a) tabular -"stratiform like" and (b) stockwork intraformational and/or dislocation stockworks in shear zones. The Re-Os molybdenite dating confirmed crystallization from igneous source in Late Permian (Lopingian; 257.2 ± 3.0 Ma to 255.6 ± 3.7 Ma) for massive vein mineralization, whereas the superimposed U remobilization within shear zones occurred in the Triassic/Jurassic period. The Kurišková U-Mo deposit represents a polygenic endo/exogenous hydrothermal deposit of the Permian/Paleo-Alpine age, with metals sourced in Permian volcanosedimentary rocks that were leached by shear zone-related meteoric fluids.

Permian A-type granites of the Western Carpathians and Transdanubian regions: products of the Pangea supercontinent breakup

“…Moreover, two distinct Permian dacitic to rhyolitic volcanic activities were recognized by U-Pb zircon geochronology from the adjacent tectonic units: an older stage (~ 290-280 Ma, Cisuralian) from the Southern Carpathians (Kędzior et al 2020) Permian evolution in the Western Carpathians is similar from a regional distribution viewpoint, as follows; the beginning of Permian volcanic activity was documented by detrital early Cisuralian magmatic zircons (300-290 Ma) in the sediments of the Hronic, and Turnaic units (Vozárová et al 2018(Vozárová et al , 2019. The main Permian volcanic activity is represented by Cisuralian to Guadalupian (~ 290-260 Ma) acidic subvolcanic porphyries, rhyolites, trachyrhyolites and rhyodacites with A-type affinity and calc-alkaline basaltic metaandesites/metabasalts with riftogeneous within-plate characteristics in Tatric, Veporic, Gemeric and Meliatic units (Broska et al 1993;Korikovsky et al 1995;Kotov et al 1996;Vozárová et al 2009Vozárová et al , 2012Vozárová et al , 2016Vozárová et al , 2020Kohút et al 2013;Putiš et al 2019a, b). These are accompanied in some places by Guadalupian volcanic dykes (270-260 Ma) which crosscut the crystalline basement in the Považský Inovec Mts., the Tatric/ Infratatric Unit (Putiš et al 2016;Pelech et al 2017) and Guadalupian A-type rhyolites (270-260 Ma) in the Muráň Nappe, Silicic Unit (Demko and Hraško 2013;Ondrejka et al 2018b).…”

Permian A-type rhyolites of the Muráň Nappe, Inner Western Carpathians, Slovakia: in-situ zircon U–Pb SIMS ages and tectonic setting

“…Permian ages of acid magmatism were also documented in the Northern Veporic Unit, including the eastern part of the Nízke Tatry Mts. (Kotov et al 1996;Bezák et al 2008;Vozárová et al 2016 and volcano-sedimentary rocks in the Permian successions of the Gemeric unit and in the Meliatic Bôrka nappe in the Inner Western Carpathians (Vozárová et al 2009(Vozárová et al , 2012Kohút et al 2013). The specific geochemistry of the dated rhyolites also reveals their origin in an extensional regime of the crust.…”

Exhumation history of the Variscan suture: Constrains on the detrital zircon geochronology from Carboniferous–Permian sandstones (Northern Gemericum; Western Carpathians)

“…The existing monazite and U-Pb SHRIMP zircon ages yield Cisuralian ages (Kungurian) for both, the acid and basic volcanic members (278 Ma -monazite, Rojkovič & Konečný 2005;272-275 Ma -U-Pb zircon ages, Vozárová et al 2012). The last volcanic phase was linked with extension at the Permian-Triassic boundary, connected with the beginning of the Alpine orogenic cycle (257.2 ± 3.0 and 255.6 ± 3.7 Ma Re-Os molybdenite ages, Kohút et al 2013; 251 ± 4 Ma U-Pb zircon ages, Vozárová et al 2015).…”