Cave monitoring in the Béke and Baradla caves (Northeastern Hungary): implications for the conditions for the formation cave carbonates

Abstract

Abstract:In order to use speleothems in the reconstruction of past climate and environmental changes it is necessary to understand the environmental and hydrological processes that determine the physico-chemical conditions of carbonate precipitation and hence speleothem formation. Therefore, in this study an extended monitoring program was conducted in the Béke and Baradla caves located in the Aggtelek region (Northeastern Hungary). The studied caves are rich in speleothem and flowstone occurrences with great potential for paleoclimatology studies. The monitoring activity included measurements of atmospheric and cave temperatures, CO 2 concentration in cave air, as well as chemical and isotopic compositions of water samples (drip water, precipitation) and in situ carbonate precipitates. The hydrogen and oxygen isotope compositions of drip waters showed no seasonal variation at any of the collection sites, indicating a well-mixed karstic aquifer. This implies that the isotopic compositions of local speleothems were able to record multiannual isotopic changes inherited from stable isotopes in the drip water. CO 2 concentration showed seasonality (high values in summer and low values in winter) in both caves, likely affecting carbonate precipitation or corrosion and consequently stalagmite growth. Systematic variations among Mg/Ca and Sr/Ca, Na/Ca, and Si/Ca element ratios were detected in the drip water suggesting Prior Calcite Precipitation (PCP). As PCP is characteristic of periods of reduced infiltration during drier weather conditions, the variations in drip water chemistry and drip rates indicate that the hydrological conditions also varied significantly during the studied period. This hydrological variability appears to affect not only trace element composition but also the isotopic composition of modern carbonate precipitates. In summary, these findings imply that the speleothems from the studied caves were able to record the hydrological changes resulting from alternating wet and dry periods, and therefore the geochemical data can be used to reconstruct past climate and environmental changes.

Effect of Systemic Subnormal Deuterium Level on Metabolic Syndrome Related and other Blood Parameters in Humans: A Preliminary Study

“…All samples were analyzed twice. For calibration three laboratory water standards [31] were used, which were prepared identically with serum samples. The uncertainty of the measurements is better than ±1.5 ppm.…”

Groundwater flow system understanding of the lukewarm springs in Kistapolca (South Hungary) and its relevance to hypogene cave formation

“…Therefore, they suggested connection possibilities of the carbonate reservoir with other deep aquifer units. In the case of the lukewarm springs in Kistapolca, Lorberer and Rónaki (1978) proposed that the cold karst waters originate from direct infiltration in the Villány Hills, and the thermal component is derived from the SW. Csicsák and Gondár (2008) suggested the effect of tectonic compression-and compaction-driven fluid flow from the South, from the sedimentary layers of the Drava Basin (part of the Pannonian Basin). Based on trace element measurements (Scheuer 2012), active tectonics induced mantle fluid contribution may also play a role in the geochemical composition of thermal waters.…”

Speleothem stable isotope reference records for East-Central Europe – Resampling sedimentary proxy records to get evenly spaced time-series with spectral control

“…Such coherences were to be expected, since the oxygen isotope composition of the speleothem is driven by temperature and drip water composition (Lachniet, 2009). Drip water composition is directly related to meteoric water composition, governed by atmospheric temperature and moisture origin in the mid-latitudes (Dansgaard, 1964), and has been documented in the surroundings of the study area (Bottyán et al, 2017;Kaiser et al, 2001). In relation to the seasonal characteristic of the response, a strong contrast exists in the seasonal water balance at the Baradla Cave.…”