Chemical composition and alter ation of Cr-spinels from Meliata and Penninic serpentinized peridot ites (Western Carpathians and Eastern Alps)

Cr-spinel is a relatively wide spread accessory mineral in the Mesozoic ophiolites of the Western Carpathians (mainly in the Meliata Unit) and in the Penninic Unit (Rechnitz tectonic window group). Cr-spinel chemical composition in both these occurrences (Meliaticum, Penninicum) shows the lherzolitic character of the original ultrabasites. It was found impossible to distinguish the source rocks (peridotites) of these two oceanic domains on the basis of the chemical composition of the Cr-spinels. Many Cr-spinels from both tectonic units are af fected by various levels of alter ation (in general, decrease of Al2O3, Cr2O3, MgO, enrichment in FeO, Fe2O3, SiO2, locally also in MnO and ZnO)

Petrology and palaeotectonic setting of Cretaceous alkaline basaltic volcanismin the Pieniny Klippen Belt (Western Carpathians, Slovakia)

Occurrences of mafic alkaline volcanics are scattered all around Europe, being mostly related to anorogenic, extensional tectonic environments. While the widespread Cenozoic alkaline basalts have been intensively studied and are comparatively well-known, their Cretaceous precursors were often associated with the Alpine-Carpathian orogenic zones, and so their genesis and geodynamic setting are partially obscured by superimposed deformation and alteration. We describe a newly discovered body of melanephelionites inserted within the Upper Cretaceous deep-marine pelagic succession of the Pieniny Klippen Belt in Western Slovakia. The body consists of hyaloclastic lavas of nephelinitic composition. The mineralogical composition and geochemical features of the Vršatec volcanites correspond to melanephelinites. Reconstruction of the geodynamic setting of the Cretaceous mafic alkaline volcanism in the Alpine-Carpathian-Pannonian realm infers a general extensional/rifting tectonic regime that ultimately led to the opening of Penninic oceanic rift arms. However, this rifting started as basically passive and non-volcanic. Only during the later, post-breakup extension phases did the slow-spreading oceanic ridges develop, which are characterized by the MORB-type (mid-ocean-ridge basin) basaltic volcanism. Alkaline volcanic provinces have a linear character and appear to follow passive continental margins of Penninic oceanic arms opened during the Jurassic and Early Cretaceous. We infer that alkaline volcanism resulted from heating and partial melting of the subcontinental mantle lithosphere on the peripheries of asthenospheric upwellings confined to slow-spreading ridges of the Alpine Tethys. Consequently, regarding the debate about the plume vs. non-plume origin of the Cretaceous alkaline volcanism, the geological data from this area rather support the latter affinity

Older linear till middle danube tumulus culture pottery—Western Slovakia sites: Results of the raw materials and production technology comparative study

In the paper we present results of multi-analytical study of pottery fragments archaeologically ranked from the Older Linear till the Middle Danube Tumulus Cultures, e.g. originated in the time-span of approximately 4700 years. In the studied set of pottery fragments we didn’t observed substantial differences of the raw materials used and temperatures of firing/annealing comparing studied set through the whole mentioned time-span didn’t surpass 650 °C in any of artefacts studied. The most realistic is to rank temperatures of firing/annealing close to the 600 °C. Oxidizing/reducing conditions during firing/annealing changed. Above statemets are based on the application of the following laboratory methods: stereoscopic observation of natural splitting planes, thin sections studies under polarizing microscope, scanning electron microscope, X-ray diffraction studies, organic matter determination (its quantity as well as quality) and the archaeopal aeomagnetic study

Tracing metamorphism, exhumation and topographic evolution in orogenic belts by multiple thermochronology: a case study from the Nizke Tatry Mts., Western Carpathians

A combination of four thermochronometers [zircon fission track (ZFT), zircon (U–Th)/He (ZHe), apatite fission track (AFT) and apatite (U–Th–[Sm])/He (AHe) dating methods] applied to a valley to ridge transect is used to resolve the issues of metamorphic, exhumation and topographic evolution of the Nizke Tatry Mts. in the Western Carpathians. The ZFT ages of 132.1 ± 8.3, 155.1 ± 12.9, 146.8 ± 8.6 and 144.9 ± 11.0 Ma show that Variscan crystalline basement of the Nizke Tatry Mts. was heated to temperatures >210 °C during the Mesozoic and experienced a low-grade Alpine metamorphic overprint. ZHe and AFT ages, clustering at ~55–40 and ~45–40 Ma, respectively, revealed a rapid Eocene cooling event, documenting erosional and/or tectonic exhumation related to the collapse of the Carpathian orogenic wedge. This is the first evidence that exhumation of crystalline cores in the Western Carpathians took place in the Eocene and not in the Cretaceous as traditionally believed. Bimodal AFT length distributions, Early Miocene AHe ages and thermal modelling results suggest that the samples were heated to temperatures of ~55–90 °C during Oligocene–Miocene times. This thermal event may be related either to the Oligocene/Miocene sedimentary burial, or Miocene magmatic activity and increased heat flow. This finding supports the concept of thermal instability of the Carpathian crystalline bodies during the post-Eocene period