Magnesium (Mg) and strontium (Sr) preserved in speleothems are among the terrestrial climatic proxies. The mechanism of their release from impurities in limestone bedrock is usually neglected in ...paleoclimatic studies mainly because it is not very well understood; most cation release studies focus on pure minerals instead of limestone. Therefore, the Mg and Sr released from six types of limestone from the Moravian Karst (Czech Republic) were studied experimentally and compared with the dripwater data coming from the Punkva Caves (Moravian Karst) formed in two of the studied limestone types. The dissolution data were used to calibrate a kinetic dissolution model. The results show an incongruent dissolution of Mg-calcite and dolomite, pronounced especially in advanced stages of the dissolution. According to the results, the trace element ratios in solution were dependent mainly on (1) the limestone composition (i.e., the Mg-calcite and dolomite availability and the stoichiometry of individual minerals) and (2) on the extent of limestone-solution interaction (controlled by dissolution dynamics). Modeling indicated that the dynamics depend on the ratios of the area of rock–water and air–water interfaces to the water volume. Moreover, modeling suggests that the dynamics and subsequently also the trace element ratios are influenced by (a) the fresh surface dissolution during the initial stages of interaction and by (b) the preferential release of trace elements from mineral surfaces (nonstoichiometric dissolution). The effects of disturbed surfaces and preferential leaching are limited by available fresh surfaces. Fresh surfaces are formed through rock crushing, e.g., during physical weathering (in the field) or sample preparation (in a laboratory). The dripwaters from Punkva Caves had trace element ratios with values between the ratios resulting from the experimental dissolution of the limestones present on the site, indicating a naturally mixed composition of waters.
This study has shown that Mg/Ca and Sr/Ca ratios in dripwaters might be controlled by various climate-independent variables, which raises further questions about utilizing the ratios as paleoclimatic proxies.
Švédův Stůl Cave in the Moravian Karst has been excavated several times since Martin Kříž started the first excavation in 1886. Two parts of the site were re-excavated in 2019. The primary aim was to ...conduct classical as well as innovative and experimental sedimentological and geoarchaeological investigations of sediments from the discarded spoil heap outside the cave entrance (trench C–D). Intact sediments with a small number of lithic artefacts and a large number of animal bones were also excavated during the 2019
excavation (trench A–B) located under the trench excavated by Bohuslav Klíma’s team in the 1950s. An attempt is being made using pXRF, benchtop ED-XRF and ITRAX techniques to link some of the sedimentary material in the spoil heap (C–D) with the stratified sediments in trench A–B. Animal bones and lithic artefacts were found in both trenches. Numerous samples were collected for geoarchaeological, palaeoenvironmental and dating
analyses and the results will be published in upcoming publications.
This article focuses on the sciurid (Rodentia, Sciuridae) remains from the early Miocene (MN4) Mokrá-Quarry sites, Moravia, Czech Republic. The sciurid assemblage in the different fissures ranges ...from one genus in MWQ4/2018 to three different genera in MCQ3/2005. Regarding subfamily Sciurinae, the dentognathic remains are referred to Palaeosciurus aff. fissurae, which shows an intermediate stage of evolution between Palaeosciurus fissurae and Palaeosciurus sutteri according to the development of conules in both upper and lower molars. Although the sciurid postcranial remains are left unassigned, several calcanei show strong morphological features belonging to ground squirrels, and, are therefore attributed to cf. Palaeosciurus. As for Pteromyinae subfamily, three genera were recovered (Miopetaurista, Blackia and Aliveria), including a new species: Aliveria mojmiri sp. nov. The new species shows a more specialised dental pattern and could further represent the ancestral species from which several middle Miocene genera evolved. Furthermore, some of the recovered calcanei have been here identified as cf. Aliveria, representing the first postcranial remains ever belonging to the genus, and confirm its attribution as a flying squirrel. The presence of both ground and flying squirrels is in concordance with an open landscape with patches of woodland proposed for Mokrá-Quarry sites.
Current knowledge about the formation of calcite rafts was summarized and expanded with new data from the environment of a technical adit excavated in the 1950s in the central part of the Moravian ...Karst (Czech Republic). The location is within the temperate zone with an average annual temperature of 7–8 °C and an annual precipitation of 550–650 mm. Two different types of calcite rafts were identified: fine floating rafts (FF rafts) and massive calcite crusts (MC rafts). The transition from the FF raft to the MC raft requires the raft to be anchored to the side bank of the water pool. Once the FF rafts are anchored, they can grow on both sides (top and bottom) of the original air-water interface to form MC rafts. A comparison of water evaporation with CO2 degassing under given conditions showed that just degassing has been the key factor in achieving adequate supersaturation of drip water for nucleation of calcite at the air-water interface and for subsequent crystal growth. The conceptual two-layer model was designed and discussed in terms of the partial pressures of CO2 in the air and water in the adit. The discussion of the role of rafts in speleogenesis and paleohydrological reconstruction is supported by examples from the Sloup-Šošůvka caves (Moravian Karst).
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•Calcite rafts are formed in an adit in the central part of Moravian Karst.•The microclimate in the adit corresponds to the microclimate of a static cave.•Two-layer model was derived to discuss the processes at water-air interface.•Degassing of CO2 was found to control calcite raft growth.•Water evaporation was insignificant under given conditions.
is a rare cricetid genus endemic to Europe, known from the Early Oligoceneto the Early Miocene. It is usually a very rare find, and even in the few localities where
remains are found, those are ...scarce and fragmentary. Only a few Central European localities have yielded rich remains of the genus. Currently, two species are known from the Early Miocene:
which is based on two teeth from the MN2 German locality of Haslach and only found in two other sites of similar age (Ulm-Uniklinik and La Chaux, from Germany and Switzerland respectively); and
found in MN3 and MN4 localities across Europe, even though the scarce and fragmentary remains make some of these attributions dubious. For that reason,
has become a catch-all species. However, Mokrá-Quarry represents one of the best documented findings of
remains from MN4 localities of Europe.
The
assemblage from Mokrá-Quarry has been studied thoroughly, providing metrics and detailed descriptions of all teeth positions, as well as complete comparisons with other MN3 and MN4 localities bearing
remains.
In this work, new remains of
have been identified as a new morphotype that clearly differs from
by its unique m1 morphology but still shows some resemblance with
Based on that, we here propose the hypothesis of an evolutionary lineage starting from
, diverging from the lineage leading towards
With this finding, there are at least two different taxa of
known during the Early Miocene, prior to the genus extinction. This study arises the certainty that the evolution history of the genus is more complex than previously thought and that more studies are necessary to elucidate it, including a complete revision of the type material of
and
in the light of current knowledge of the genus, which will help to elucidate the attribution of the populations from Mokrá-Quarry. For the time being, the assemblage presented here is referred as
aff.
Pod Hradem Cave, located in the Moravian Karst, Czech Republic, offers an excellent opportunity for environmental reconstructions of Marine Isotope Stage 3 (MIS 3) in Central Europe due to its ...detailed sedimentary record dated 50,000 to 28,000 cal BP. Identifying the natural environments of the Middle to Upper Palaeolithic (MUP) transition is necessary to understand the settlement strategies and related behaviour of both Neanderthals and Anatomically Modern Humans, both of whom may have occupied the region at the same time. A multidisciplinary excavation was carried out between 2011 and 2016. Detailed analyses of the sediments, vertebrate microfauna, pollen and charcoal revealed minor but observable fluctuations in climate, with little change in the surrounding vegetation. The Pod Hradem palaeoenvironmental dataset is complex, but generally reflects a predominantly glacial climate with a range of vegetation types and habitats during the Late Pleistocene, followed by the warmer and more humid Holocene. The MUP transition as recorded in Pod Hradem Cave was a glacial environment interrupted by two relatively warmer periods. Central Europe experienced extreme climate fluctuations during MIS3, as recorded from different sedimentary archives, but it seems that the Pod Hradem Cave environment may have acted as a buffer zone, ameliorating those extremes, and providing a suitable refuge for both bears seeking winter hibernation dens and occasionally visiting humans.
•Sediment microstructures reveal cold and warm periods between 28,000–50,000 cal yr BP.•Cave sediments accumulated mainly by colluviation from cave entrance and roof fall.•Humans visited the cave during both warm and cold periods.•Steppe-like landscape with a mosaic of vegetation communities throughout MIS3
A multidisciplinary correlation of the Devonian-Carboniferous (D-C) boundary sections from the Moravian Karst (Czech Republic) and the Carnic Alps (Austria), based on conodont and foraminifer ...biostratigraphy, microfacies analysis, field gamma-ray spectroscopy (GRS), carbon isotopes and element geochemistry, is presented in this paper. The study is focused on the interval from the Middle Palmatolepis gracilis expansa Zone (Late Famennian) to the Siphonodella sandbergi Zone (Early Tournaisian). In Lesni lom (Moravian Karst), a positive δ13C excursion in the Bisphatodus costatus - Protognathodus kockeli Interregnum from a distinct laminated carbonate horizon is correlated with a carbon isotope excursion from the Grune Schneid section of the Carnic Alps and is interpreted as the equivalent of the Hangenberg black shales and a local expression of the global Hangenberg Event sensu stricto. Higher up at both sections, a significant increase in the terrigenous input, which is inferred from the GRS signal and elevated concentrations of terrigenous elements (Si, Ti, Zr, Rb, Al, etc.), provides another correlation tieline and is interpreted as the equivalent of the Hangenberg sandstone. Both horizons are discussed in terms of relative sea-level fluctuations and palaeoceanographic changes. Recent studies show that conodont biostratigraphy is facing serious problems associated with the taxonomy of the first siphonodellids, their dependence on facies and discontinuous occurrences of protognathodids at the D-C boundary. Therefore, the correlative potential of geochemical and petrophysical signatures is high and offers an alternative for the refining of the problematic biostratigraphic division of the D-C boundary.
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