The occurrence of 226Ra and 228Ra in groundwaters of the Polish Sudety Mountains

The paper presents preliminary measurement results of the concentrations of 226Ra and 228Ra isotopes in the groundwaters of the Polish part of the Sudety Mountains. The analysis of sampling results for water from 55 intakes showed that the average concentrations amount to 0.144 Bq/dm3 for 226Ra and 0.083 Bq/dm3 for 228Ra, while the extreme values reach 0.007 and 0.92 Bq/dm3 for 226Ra, and 0.004 and 0.4 Bq/dm3 for 228Ra. The activity ratio 228Ra/226Ra in the examined groundwaters ranges between 0.099 and 2.059. The result of the conducted research implies that the highest concentrations of 226Ra and 228Ra occur in the waters with the highest general mineralization (the highest values of total dissolved solids (TDS))

Natural radioactivity of groundwater from the Przerzeczyn-Zdrój Spa

The present authors performed investigations of natural radioactivity in groundwater from the Przerzeczyn- -Zdrój Spa. Some of the waters are regarded as medical and are used for balneological purposes. Samples from seven groundwater intakes were collected 5 times over a period of 8 years (1999–2007). In order to obtain necessary data, two different nuclear spectrometry techniques were applied: α spectrometry and liquid scintillation spectrometry. The activity concentrations of 222Rn varied in the range from 15±2 Bq/l to 154±22 Bq/l. The results of activity concentrations of 226,228Ra varied from below 10 mBq/l to 30±1.5 mBq/l and from below 30 mBq/l to 60±4 mBq/l, respectively. Activity concentration lower than minimum detectable activity (MDA) was obtained for 3 samples for 226Ra and 4 for 228Ra determinations out of 7 investigated samples. The uranium content in the studied samples was determined once and the value ranged from 4.5±0.6 mBq/l to 13.6±1.2 mBq/l for 238U and from 17.1±0.9 mBq/l to 52.2±2.8 mBq/l for 234U. All obtained values for uranium isotopes showed activity concentrations above MDA. The activity ratios 234U/238U, 222Rn/226Ra and 226Ra/238U and the correlations between different isotopes concentrations were evaluated

National comparison of methods for determination of radon in water

The article describes three interlaboratory experiments concerning 222Rn determination in water samples. The fi rst two experiments were carried out with the use of artifi cial radon waters prepared by the Laboratory of Radiometric Expertise (LER), Institute of Nuclear Physics, Polish Academy of Sciences in Kraków in 2014 and 2018. The third experiment was performed using natural environment waters collected in the vicinity of the former uranium mine in Kowary in 2016. Most of the institutions performing radon in water measurements in Poland were gathered in the Polish Radon Centre Network, and they participated in the experiments. The goal of these exercises was to evaluate different measurement techniques used routinely in Polish laboratories and the laboratories’ profi ciency of radon in water measurements. In the experiment performed in 2018, the reference values of 222Rn concentration in water were calculated based on the method developed at LER. The participants’ results appeared to be worse for low radon concentration than for high radon concentrations. The conclusions drawn on that base indicated the weaknesses of the used methods and probably the sampling. The interlaboratory experiments, in term, can help to improve the participants’ skills and reliability of their results

Radon intercomparison tests – Katowice, 2016

At the beginning of the year 2016, the representatives of the Polish Radon Centre decided to organize profi ciency tests (PTs) for measurements of radon gas and radon decay products in the air, involving radon monitors and laboratory passive techniques. The Silesian Centre for Environmental Radioactivity of the Central Mining Institute (GIG), Katowice, became responsible for the organization of the PT exercises. The main reason to choose that location was the radon chamber in GIG with a volume of 17 m3, the biggest one in Poland. Accordingly, 13 participants from Poland plus one participant from Germany expressed their interest. The participants were invited to inform the organizers about what types of monitors and methods they would like to check during the tests. On this basis, the GIG team prepared the proposal for the schedule of exercises, such as the required level(s) of radon concentrations, the number and periods of tests, proposed potential alpha energy concentration (PAEC) levels and also the overall period of PT. The PT activity was performed between 6th and 17th June 2016. After assessment of the results, the agreement between radon monitors and other measurement methods was confi rmed. In the case of PAEC monitors and methods of measurements, the results of PT exercises were consistent and confi rmed the accuracy of the calibration procedures used by the participants. The results of the PAEC PTs will be published elsewhere; in this paper, only the results of radon intercomparison are described

Meteoroid and meteorite. Back to basics and definitions

The authors drew attention to the classification in December 2022 of over one ton of lunar meteorites that fell to Earth. They have been found since the early 1960s, but their first classification, as lunar meteorites, was made only in 1982. This was possible thanks to more advanced geochemical research and the possibility of comparing their results with the results of analyzes of samples of rocks and lunar regolith brought by the Soviet missions of the Luna program, and above all by several American missions of the Apollo program. With access to over 1.4 tons of lunar rocks on Earth, we are now able to conduct multidisciplinary studies of the lunar geology. Their results are particularly important in the context of building human settlements or lunar bases for further exploration of the solar system. This applies to both the physical properties of these rocks, as well as their chemical and mineral composition in the context of the presence of deposits of various mineral resources. It should be emphasized that meteoritic material from the Moon has been increasing in terrestrial collections (especially scientific ones) very quickly since 2015. This is the result of extensive exploration work, primarily in Antarctica, Africa, the Arabian Peninsula and Australia. Among the identified rocks reaching the Earth in the form of lunar meteorites, the most numerous are feldspar breccias (impact metamorphic rocks), anorthosites (plutonic igneous rocks building highlands areas of the silver globe) and basalts (extrusive igneous rocks building areas of the lunar maria). In addition, there are other igneous mafic rocks, such as gabbro, norite, troctolite and others. The surface of the crust is covered with regolith composed of fragments of the above-mentioned igneous rocks and breccias subjected to fragmentation by successive collisions with meteorites and micrometeorites and the action of solar wind particles (space weathering). As a result of these processes, the surface of the Moon is covered with a layer of loose sedimentary rock with a thickness of a few to several meters. Locally, a regolith may be a compact clastic sedimentary rock if a significant number of rock fragments are welded together with the glaze produced during collisions with micrometeorites. The authors also briefly presented the genesis and evolution as well as the geological structure of the Moon based on the results of the latest geophysical and geochemical (including isotopic) as well as mineralogical and petrological research. They pointed out that the proposed model of the genesis of the Moon from synestia formed after the collision of the proto-Earth with another hypothetical planetary embryo called Theia, explains well the chemical and isotopic homogeneity of the Earth and the Moon. The authors also pointed out that due to the common genesis, lunar meteorites are classified and named in the same way as terrestrial rocks, which definitely distinguishes them from other meteorites. The exceptions are Martian and HED meteorites, which are classified similarly to terrestrial rocks, although their names often do not have equivalents in the classification of terrestrial rocks (e.g. SNC meteorites). Tracking data on officially classified lunar meteorites, the authors found that in December 2022, the total mass of meteoritic matter considered to coming from the Moon exceeded 1 ton. Lunar meteorites are currently the largest source of information about the geology of the Silver Globe, accounting for almost two-thirds of the mass of lunar material available for study on Earth

Sołtmany chondrite

The Sołtmany hammer meteorite is classified as an ordinary chondrite type L6, W0, S2. At present it is the most thoroughly and comprehensively examined Polish meteorite. A comprehensive petrological, mineralogical and geochemical analysis alongside the investigation of its physical and particularly thermophysical properties, and, most of all, analyses of cosmogenic radionuclides and noble gases isotopes content, as well as the use of a troilite thermometer has made it possible to draw interesting conclusions concerning the genesis and evolution of the parent body and the history of the parent meteoroid and, finally, the Sołtmany meteorite. The present report attempts at summing up the results of studies conducted at several European research centres in the last four years. The age of the the Sołtmany chondrite parent rock has been defined at 4.137 billion years. It was formed at a temperature of up to 440–450 K (about 170°C), probably at a depth of up to 3 to 7 km under the surface of the parent body, i.e. at a pressure of the order of 1–2.4 kbar. Such a low temperature during the accretion, diagenesis and metamorphism of the parent body may point to its complicated development, which may be in part due to collisions of partially melted planetesimals. Like with other type L ordinary chondrites, one can infer that the parent body could have been destroyed about 467 million years ago, at the time of a catastrophic collision which led to the formation of Gefion family of planetoids. Perhaps one of the bodies in this family was involved in another collision about 29.2 million years ago, which resulted in ejecting the parent meteoroid of the Sołtmany chondrite onto the Earth collision trajectory. Before entering the Earth’s atmosphere, this meteoroid had the mass of about 36 kg and the diameter of ca 13.5 cm. During its flight through the atmosphere, it rotated and somersaulted, which resulted in the formation of an uniform thin (0.5–0.7 mm) fusion crust, whose temperature reached 1000°C. In the last phase, the Sołtmany meteorite fell almost vertically and its mass was a mere 3% of the mass of the parent meteoroid – 1.066 kg. It hit the roof and then the concrete stairs of a farm building, which caused it to break into two bigger and many small pieces. It was found a few minutes after the fall, which occurred at 6:03 a.m. (CEST, UTC+2:00) on 30 April 2011, by Wydmińskie Lake in northern Poland (54°00,53’N, 22°00,30’E). The Sołtmany chondrite is one of just 14 meteorites in which the activity concentration of the cosmogenic 52Mn has been determined, and one of the few ordinary chondrites where the concentration of organic matter has been defined. As a result, it was found out that unlike in carbonaceous CI chondrites, the composition of organic particles is dominated by less complex compounds (CHO and CHOS) than CHNO and CHNOS compounds. This may indicate the decomposition of more complex organic compounds into particles with simple structures during magmatic and metamorphic processes related to formation of type L ordinary chondrites

Potentially medicinal radon waters of the eastern part of the High Ridge in the Izera Range (Sudetes), containing the greatest radon concentration in Poland

In the years 2020-2022, the authors conducted research on the activity concentration of 222 Rn in the groundwater of the eastern part of the Izera metamorphic unit. As a result, they found potentially medicinal radon waters in hornfelses of the eastern part of the Szklarska Poręba band. The value measured in one of the water samples appeared to be the highest activity concentration of 222Rn in groundwater of Poland so far - 3368 ±61 Bq/dm3. The authors also found that outflows of potentially medicinal radon waters account for almost 85.5% (47 out of 55) of all groundwater outflows in the study area. Thanks to the large amount of data obtained, the authors calculated a new value of the hydrogeochemical back-ground of 222 Rn in the groundwater of the Izera metamorphic unit. The background is currently 17-890 Bq/dm3. In Poland, higher values have only been reported of the Lądek-Śnieżnik metamorphic unit. The research results also open the way to the possible creation of a modern radon spa in Szklarska Poręba. It could operate in Biała Dolina on the basis of both previously found resources of radon waters of the Karkonosze granite and the radon waters forming within the eastern part of the Izera metamorphic unit

Composition of Ordinary Chondrites and Potential Natural Resources of Asteroid Belt

In this article the authors present a simple method of determining the content of selected metal raw materials (Fe, Ni, Co) on the parent bodies of ordinary chondrites. Thanks to the use of planimeter for measuring, under microscope, polished slices of meteorites, it is possible to estimate quite accurately the proportion of these metals in the parent bodies of meteorites, i.e. on asteroids. When it comes to analysing a large number of polished slices, these results will be most likely comparable to much more expensive results of chemical tests conducted on meteorites. Based on the analysis of 16 thin polished sections and polished slices of 11 ordinary chondrites, the authors found out that the highest content of Fe, Ni and Co ore minerals, reaching 10,06% of the total volume, can be found in ordinary chondrites from group H. For ordinary chondrites from groups L and LL, it makes 3,86% and 3,93% of the volume respectively. Employing the results of chemical analyses available in literature sources, the authors also estimated the size of Fe, Ni and Co resources for several selected asteroids. These bodies contain higher concentrations of iron, nickel and cobalt than terrestrial deposits (those found in the earth’s crust). The total content of Fe on parent bodies of even the most deficient in metals group LL of ordinary chondrites is about twice as high as that in the earth’s crust. Cobalt occurs on parent asteroids of ordinary chondrites in concentrations 15–24 times as high as those in the earth’s crust, and the concentrations of Ni are 100–180 times as high as those in the earth’s crust. The contents of these metals on parent asteroids of ordinary chondrites are also several times as high as those in currently extracted deposits in the earth’s crust. Taking into account the mean annual terrestrial production of these metals, the authors have estimated that a parent asteroid of ordinary chondrites with the size between 433 Eros and 6 Hebe could satisfy our need for Fe, Ni and Co for the nearest several million to dozens of billion years. Considering the fact that asteroid belt contains plenty of such objects, and as many asteroids built chiefly of Fe-Ni alloy, one should regard this section of the Solar System as a practically inexhaustible source of metal raw materials. The prospect of their exploitation is probably much nearer than we can currently imagine