Our knowledge of the plant diet of the last European hunter-gatherers is hindered by the difficulties of recording poorly durable plant tissues. One exception is the hazelnut fruit, which preserves ...well at dry archaeological sites, although usually only in a charred state. Here we give the first evidence for the prehistoric (Mesolithic) use of seeds of the Swiss stone pine, specifically for the time period 8239 − 7943 cal
bc
, when this edible seed-bearing tree was an important element of local boreal forests in northern Bohemia, Czech Republic. This local population of Swiss stone pine became extinct at the end of the Early Holocene without leaving modern offspring in the lowlands and middle elevations of central Europe.
The Morava River catchment in the Czech Republic serves as sedimentary archive reflecting various natural and man-made processes, and was studied by several authors from the point of view of flood ...frequency, anthropogenic contamination, or alluvial history. However, more consistent and detailed information on the effect of human activities, namely in terms of land use and river regulation, is missing. The aim of this study is to reconstruct the palaeoenvironmental and anthropogenic processes affecting the floodplain sediments in this area, focusing on the last few hundreds of years. Alluvial sediments from river banks and drilled cores were collected in the Strážnické pomoraví area from sites both inside and outside dams constructed to avoid flooding. Magnetic parameters, reflecting the composition and grain-size distribution of iron oxides, which serve as fingerprints of lithogenic vs. pedogenic vs. anthropogenic origin, are complemented by the radiocarbon and dendrochronological dating. In addition, deposition age was estimated using the 137Cs activity and persistent organic pollutant content. Our results reveal continuous increase of ferrimagnetic minerals (magnetite) input to the floodplain, suggesting increased soil erosion in the catchment. Significantly different pattern was observed inside and outside the flood dykes. The erosion accelerated since the 1950s due to incorrect land use and introduction of modern agriculture techniques. Finally, the industrial pollution significantly contributes to the magnetic enhancement of the topmost 50 cm of the floodplain sequences. Although the results represent local case study, they have more general validity in the sense that records of paleoenvironmental changes and human activities in floodplain sediments may not be well preserved in all the strata, and also their spatial distribution of individual markers may show significant variability.
Display omitted
•Input of ferrimagnetic minerals to floodplain sediments increased in the last 400–600 years.•Increased soil erosion due to incorrect land use supplies ferrimagentic oxides to the floodplain sediments.•Atmospheric deposition of industrial emissions contributes the most recent magnetic enhancement.•Unearthing detailed flood record is obstructed by diagenesis and redeposition.
Due to their electromagnetic properties, thunderclouds can act as natural particle accelerators. Electrons accelerated in the thunderclouds can reach energies up to tens of MeV. Large populations of ...high energetic electrons formed by avalanche growth driven by electric fields in the Earth atmosphere called Relativistic Runaway Electron Avalanches (RREA) propagate through matter. They are decelerated and deflected in the course of collisions with particles in the atmosphere and emit gamma rays known as bremsstrahlung. The produced gamma rays can further trigger photonuclear reactions in the air and soil. This article reports on the work of project CRREAT (Research Centre of Cosmic Rays and Radiation Events in the Atmosphere), studying various lightning-related phenomena in various ways, both
in situ
and in the laboratory. This paper focuses on the simulation of the laboratory experiments at the Microtron accelerator in Prague and the neutron generator in Ostrava, where we irradiated various soil samples with 20 MeV electron beams. Experiments showed which radionuclides can be formed during the reactions of high-energy electrons with various soils and can be as targeted products in the thunderstorm radiation effect analysis. Radionuclides produced in exposed samples were measured using a highpurity germanium (HPGe) detector. A computer simulation was done with a simple source and sample geometry using the general-purpose 3D Monte Carlo code PHITS.
The first accelerator mass spectrometry (AMS) laboratory in the Czech Republic has been established and put into routine operation in February 2022. Here we briefly describe the facilities available, ...namely a 300 kV multi-isotope low-energy AMS system (MILEA) capable of determination
10
Be,
14
C,
26
Al,
41
Ca,
129
I, isotopes of U, especially
236
U, Pu and other actinoids, and accessories for
14
C measurements, which include a gas interface system, a preparative gas chromatography system for compound-specific radiocarbon dating analysis, and an isotope-ratio mass spectrometer. The first results achieved for separation and measurement of the above radionuclides (except for
41
Ca) are also reported, with the main focus on
14
C measurements. A specimen breakdown of 729 graphitised samples analysed for
14
C so far is presented, as well as a proof of measurement stability of the MILEA system obtained by analysis of radiocarbon standards and analytical blanks. For the other radionuclides, well proven or novel procedures for sample preparation and measurement are presented.
Total nitrogen content via instrumental photon activation analysis was determined to reveal the matrix composition of the bracelet from the late Bronze Age found in the site (hill fort) Soví Skály in ...Karlovy Vary – Drahovice (Drahovice cadastre, Czech Republic) from the collections of the Museum Karlovy Vary. Its exact age was determined by radiocarbon dating.
The Southern Corridor of bishopric district was uncovered in early 1920s as the first Romanesque remains in the 3rd Courtyard of the Prague Castle. Based on historical context it likely originates ...from 11th − 12th century. To benchmark this estimate, radiocarbon dating of charcoals found in its mortars was performed. The results support the previous age estimate and suggest an ongoing building activity on site such as raising cascade walls at least till 14th − 16th century.
ABSTRACT
The fifth season of excavations of Oponice Castle in 2020 was located in the lower castle’s courtyard. The research led to discovery of an original clay floor being heavily burned with ...charred plank and a rectangular stone-brick construction. The construction has collapsed upper part with a fallen low brick arch. The whole area was covered with numerous stove tiles and one clay mold for the production of stove tiles. The construction was identified as a pottery kiln dated to the second half of the 16th until the first half of the 17th century AD by the findings from excavated layer identified to the kiln destruction. Also, written sources mention a large fire in 1645 which destroyed the castle. The aim of this article is to use different methods of dating and refine the chronology of the context through microarchaeology and Bayesian modeling. For these purposes different types of samples were collected. The sampling focused on site formation process determination of pottery kiln use and the way of its destruction. Applying Bayesian analysis improved overall dating, through modeled time interval of the three individual sequences and helped recreated historical events during the period, when the calibration curve fluctuates.
Coal petrology data and vitrinite reflectance modelling were combined with micro-geochemical and fluid inclusion analyses of coal mineralization and apatite fission track analysis (AFTA) of ...coal-bearing sediments to constrain the thermal history of the Blanice Graben, a narrow, nearly 150-km long, late-Variscan strike-slip basin filled with Permo-Carboniferous continental coal-bearing deposits. The vitrinite reflectance modelling and the ranking of coals, which increased along the meridional axis of the graben from bituminous coals (Rr ∼ 0.70%) to high-rank anthracites (Rr = 2.85–4.77%), provide evidence of maximum palaeo-temperatures ranging from about 120–145 °C to 310–390 °C. This corresponds to the diagenetic realm in the north of the graben that graded to high-grade anchizonal to low-epizonal metamorphic conditions in the south. The present level of coalification resulted from the Permian burial, 2500–5000 m thick, which aggregated under a high geothermal gradient (∼ 90 °C/km). In central and southern relics of the graben, however, specific microscopic features of coals and fluid inclusion and chlorite thermometry suggest that the anthracite rank was attained by the combined effect of a stratigraphic burial, a regional discharge of ∼300 °C hot, mineralized fluids that ascended along faults into buried coal-bearing strata and an intense Permian faulting and shearing of coal seams, which collectively contributed to the anthracitization process. The heat source, promoting high geothermal gradient and circulation of hot fluids through the coal-bearing sediments, was probably associated with a mantle magma chamber hidden deeply below the graben and manifested at current errosional level by ∼303 and ∼ 270 Ma old microdiorite dykes. Similar dramatic geothermal settings, characterized by elevated geothermal gradients, localized fault-controlled incursions of hot hydrothermal solutions, and rapid coalification of peat layers at relatively shallow depths of burial, dominated in many late Variscan coal-bearing basins during a period of post-collisional extension at ∼315–280 Ma. The AFTA method, applied to sedimentary apatites, provides evidence that following the climax of the Variscan orogeny, the Blanice Graben coal-bearing deposits were rapidly uplifted and, throughout the Mesozoic and Cenozoic times, they experienced only prolonged slow cooling (0.46–0.54 °C/My) and moderate burial temperatures of 50–70 °C. Its final ascent towards the present-day erosional surface occurred during a period of accelerated uplift that has affected the Bohemian Massif since the Oligocene.
ABSTRACT
An archaeological excavation conducted on U Kasáren St. in the Prague Castle area (Czech Republic) in 2020 revealed the remains of a medieval settlement consisting of houses of different ...constructions (pit dwelling, masonry construction), pyrotechnical (possibly metallurgical) features and unspecified pits. The excavation also revealed evidence of fire events and traces of viniculture on the outskirts of the Prague Castle area. Archaeological data allowed only a rough dating of the investigated settlement in the 10th–13th centuries. This paper presents the results of the radiocarbon dating of various materials (animal bones, archaeobotanical samples) from the settlement features and the contribution of the results to the clarification of the chronology of the site.
The performance of a new Multi-Isotope Low-Energy AMS (MILEA) system developed in a cooperation of Ionplus AG and ETH Zurich, Switzerland for determination of 10Be, 14C, 26Al, 41Ca, 129I, and ...actinoids (233U and 236U) is described based on results of factory- and on-site acceptance tests carried out at the producer and customer sites, respectively. The parameters measured were transmissions from the injector to the detector, currents in the high energy part of MILEA, radioisotope/stable blank ratios or abundance sensitivity, single sample and overall sample scatter of the radioisotope/stable isotope ratios. The results achieved were competitive with larger AMS systems.
