222Rn and 220Rn concentrations in selected soils developed on the igneous rocks of the Kaczawa Mountains (Sudetes, Poland)

This study presents the preliminary results of 222Rn (radon) and 220Rn (thoron) concentrations that were measured in the soils developed on igneous rocks including mafic (pillow lavas, basalts and melaphyre) and acid (keratophyre, rhyolite and rhyolitic tuff) rocks at ten locations in the Kaczawa Mountains (SW Poland). The measurements were carried out at sampling depths of 10, 40 and 80 cm using a RAD7 portable radon system. The highest concentrations of radon (222Rn) were mainly observed in the soils overlaying acid igneous rocks. The highest value of 11 kBq m-3 was obtained at a depth of 10 cm for soils overlaying melaphyre. At depths of 40 and 80 cm, the averages of 222Rn concentrations showed the same values of 3.6 kBq m-3 for all of the soils investigated. The highest concentrations of thoron (220Rn) were observed in soils overlaying acid igneous rocks, i.e. the value of 49 kBq m-3 at a depth of 40 cm for soils overlaying rhyolitic tuff. In the soils developed on basalts, the average concentrations of 222Rn increased with the sampling depth, whereas the average concentrations of thoron (220Rn) decreased with increasing sampling depth. Positive correlations were found between 232Th activity in the parent rocks and soil gas 220Rn concentrations at all of the sampling depths, whereas a positive correlation between soil gas 222Rn and the 238U activity concentration in the parent rocks was only found at a depth of 40 cm

In situ measurements of natural radioactivity in selected igneous rocks of the Opava Mountain region

In situ gamma-ray measurements of four igneous rocks were taken in the Opava Mountains (Eastern Sudetes, Poland). The activity of naturally occurring radionuclides was measured using a portable GX3020 gamma-ray spectrometry workstation. The activity concentrations of 40K varied from 914 ± 17 Bqkg-1 (gneiss, Kamienna Góra) to 2019 ± 37 Bqkg-1 (weathered granite, Sławniowice), while those of 232Th from 7.5 ± 0.6 Bqkg-1 (weathered granite, Sławniowice) to 68 ± 0.9 Bqkg-1 (migmatitic gneiss, Nadziejów). The activities associated with 238U decay series ranged from 10 ± 0.4 Bqkg-1 (weathered granite, Sławniowice) to 62 ± 1.6 Bqkg-1 (gneiss, Kamienna Góra). The results will be used in compiling Radiological Atlas of the Sudetes

Natural radioactivity in granites and gneisses of the Opava Mountains (Poland) : a comparison between laboratory and in situ measurements

The natural radioactivities of five characteristic igneous rocks of the eastern foreland of the Opava Mountains (Eastern Sudetes, Poland), obtained in the laboratory and under in situ conditions, are presented. The activity concentrations of 232Th, 238U, and 40K were measured using an HPGe gamma-ray spectrometry system. The ranges of the activity concentrations of 232Th were 7–71 Bq kg-1 in the laboratory and 6–68 Bq kg-1 for the in situ measurements. For 238U, the ranges of the activity concentrations were 5–52 Bq kg-1 in the laboratory and 9–48 Bq kg-1 for the in situ measurements, and for 40K, the ranges were 520–1560 Bq kg-1 in the laboratory and 537–1700 Bq kg-1 for the in situ measurements. These determined activity concentrations were compared with the average activity concentrations of the radionuclides in similar types of rocks and with data from the Sudetes available in the literature. No significant differences were found between the in situ and laboratory measurements

Wpływ minerałów metalonośnych na biotyczne składniki wierzchnich warstw składowisk odpadów z flotacji rud cynku i ołowiu

The mineral components of topsoil in the zinc and lead flotation tailings ponds were analyzed. To examine such mineral components the authors used methods such as scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and atomic absorption spectroscopy (AAS). The goal of this study was to pay particular attention to the secondary metalliferous mineral phases formed in rhizosphere zones mainly on plant roots and the influence of autochthonous sulphur bacteria and ferric bacteria on the chemical mechanism of waste components. This study aims both to recognize the (bio)chemical change of flotation tailings which is of great significance for the vegetation of plants, fungi and microorganisms and to properly plan the treatment connected with reclamation and phytoremediation of the area affected by waste disposal

Identification of iron-bearing minerals in basalts and pillow lavas of the Kaczawa Mountains using 57Fe Mössbauer spectroscopy

The Kaczawa Mountains along with the Kaczawa foothill comprise a complicated geological unit that is called the Kaczawa metamorphic (Sudetes, SW Poland). The aim of our work was to identify the iron-bearing minerals in samples of basalts and pillow lavas from the Kaczawa metamorphic using 57Fe Mössbauer spectroscopy. Based on the preliminary results, the Fe3+/Fe2+ ratio in the samples was determined

Laboratory measurements of natural radioactivity in selected igneous rocks of the Opava Mountains region

The paper presents results of laboratory gamma–ray measurements of six igneous rocks from the Opava Mountains. The Opava Mountains are located in the Eastern Sudetes and represent their furthest eastern range. They run almost latitudinally along the Polish border with the Czech Republic. The Opava Mountains are situated mostly in the Czech Republic. Only a small fragment between Głuchołazy in the west and Prudnik in the east is situated in Poland (Janeczek et al. 1991) .  The study area is built of rocks of different ages and lithologies. The Opava Mountains belong to the western part of the Upper Silesia Block, which together with the Brno Block form a structure that is called the Brunovistulicum. The mountains consist of five structural stages: the Žulova Massif, the Desna Series, the Vbrna Series, the Andělská-Hora Formation and the Horn-Benešov Formation, which run longitudinally (Żaba et al. 2005). The activities of naturally occurring radionuclides were measured using a portable GX3020 gamma-ray workstation. The system is based on a high-purity germanium (HPGe) detector with 32% relative efficiency and energy resolutions of 0.8 keV at 122 keV and 1.7 keV at 1330 keV.). The activity concentrations of 40K varied from 519 Bqkg-1 (paragneiss, Głuchołazy/Mikulice) to 1559 Bqkg-1 (weathered granite, Sławniowice), while those of 228Ac (232Th series) from 7.2 Bqkg-1 (weathered granite, Sławniowice) to 70.6 Bqkg-1 (migmatitic gneiss, Nadziejów). The activities associated with 226Ra (238U series) ranged from 5.5 Bqkg-1 (weathered granite, Sławniowice) to 52.2 Bqkg-1 (gneiss, Kamienna Góra). Measured activity concentrations were compared with the average activity concentration of 40K, 228Ac (232Th) and 226Ra (238U) for similar types of rocks. For the authors’ knowledge, this paper presents the first experimental data concerning activity concentrations of primordial radionuclides in the igneous rocks in the Opava Mountains

Natural Radioactivity of Rocks from the Historic Jeroným Mine in the Czech Republic

This study reports the natural radioactivity of characteristic rocks found in the historic Jeroným Mine of the Czech Republic as measured under the laboratory conditions. The rocks analyzed included granites and schists weathered to varying degrees and collected from different levels of the underground workings of the Jeroným Mine. The mine itself has been subject to metal extraction (mainly tin and tungsten) since the sixteenth century and has recently been developed as a cultural and scientific attraction open to the public. Activity concentrations of 40K, 232Th and 238U were measured from nine rock samples using gamma-ray spectrometry. The activity concentrations of 40K varied from 595 Bq kg−1 to 1244 Bq kg−1, while 232Th varied from 25 Bq kg−1 to 55 Bq kg−1. The activities associated with 238U ranged from 46 Bq kg−1 to 386 Bq kg−1. The measured activities were used to estimate two radiation hazard indices typically applied to building materials, the activity concentration index I and the external hazard index Hex. Mean respective values of 1.02 and 0.77 for I and Hex indicate that the rocks found in the Jeroným Mine meet radiological safety standards for building materials and do not pose a risk to potential tourists and staff

⁵⁷Fe Mössbauer Spectroscopy and X-ray Diffraction of Annealed Highly Metamict Perrierite: Activation Energy and Recrystallization Processes

This paper presents the results of 57Fe Mössbauer spectroscopy and X-ray diffraction analysis of highly metamict perrierite (REE,Ca,Th)4(Fe2+,Mg)2(Ti,Fe3+)3Si4O22 after annealing in argon from 673 to 1273 K for one hour. Radioactive elements in metamict minerals damage crystal structure on geologic time scales primarily due to recoil nuclei from α-decay of 238U, 232Th, 235U, and their daughter products. Metamict minerals are widely used in geochronology and can serve as natural analogs for the study of radiation effects in high-level nuclear waste. Analyses were performed on fragments of a perrierite sample collected from granitoids near Amherst, Virginia (USA). Electron microprobe and gamma-ray spectrometry recorded Fe concentrations of 4.7 wt.% and Th and U concentrations of 0.64 and 0.06 wt.%, respectively. The calculated total absorbed α-dose was 7.8 × 1015 α-decay mg−1. The Mössbauer spectrum of the untreated sample can be fitted to two Fe2+ and two Fe3+ doublets in octahedral coordination with a relative ΣFe2+/ΣFe of 0.63. For samples annealed at 1173 K and 1273 K, spectra show a decrease in the total contribution of Fe2+ to 0.58 due to dehydroxylation associated with the simultaneous oxidation of post-metamict Fe2+ to Fe3+. In the examined perrierite, Fe2+ occurs in structural positions B and C(1). The broad, predominant Fe3+ doublet observed in the spectrum of the unannealed sample splits into two components at 973 K interpreted to represented positions C(1) and C(2) in the perrierite structure. The Mössbauer spectra show a prominent decrease in the width of the high-energy absorption peak representing Fe2+ components with increasing temperature. The variation in the width of this peak versus the annealing temperature seems to be an indicator of thermally induced recrystallization. Based on the exponential dependence of the derivative function of the parameter with the inverse temperature and using an Arrhenius plot, an activation energy (EA) of 0.73 eV was determined for thermally-induced recrystallization. Corresponding XRD data show progressive recrystallization with increasing annealing temperature. The XRD pattern of the fragment annealed at 1273 K indicates that highly metamict perrierite recrystallized to the pre-metamict state that can be indexed to the C2/m space group

Identification of iron-bearing minerals in basalts and pillow lavas of the Kaczawa Mountains using 57Fe Mössbauer spectroscopy

The Kaczawa Mountains along with the Kaczawa foothill comprise a complicated geological unit that is called the Kaczawa metamorphic (Sudetes, SW Poland). The aim of our work was to identify the iron-bearing minerals in samples of basalts and pillow lavas from the Kaczawa metamorphic using 57Fe Mössbauer spectroscopy. Based on the preliminary results, the Fe3+/Fe2+ ratio in the samples was determined