Search

Hypogene caves in the Plavecký hradný vrch Hill (Western Slovakia, Central Europe) were formed by waters ascending along faults in fractured Triassic carbonates related to the horst-graben structure at the contact of the Malé Karpaty Mountains and the NE part of the Vienna Basin. The Plavecká jaskyňa and Pec caves mostly contain horizontal passages and chambers with flat corrosion bedrock floors, fissure discharge feeders, wall water-table notches, replacement pockets, as well as a few other speleogens associated with sulfuric acid speleogenesis. The low-temperature sulfuric acid development phases of the Plavecká Jaskyňa are also indicated by the presence of sulfate minerals (i.e., gypsum and jarosite). Subaerial calcite popcorn rims were precipitated from water condensation at the edges of feeding fissures that were still active as thermal vents when the water table dropped. Hydrogen sulfide involved in the sulfuric acid speleogenesis was likely derived from anhydrites and/or hydrocarbon reservoirs with sulfate-saline connate waters in the fill of the adjacent Vienna Basin. It ascended to the surface along deep-rooted sub-vertical fault zones at the contact of the Vienna Basin with neighboring mountains. Three cave levels at 295 to 283 m asl in the Pec Cave, and five levels at 225 to 214 m asl in the Plavecká jaskyňa corresponded to phases of stable local erosional base levels in the bordering part of the Vienna Basin, most likely during periods of strongly decelerated and/or interrupted subsidence. Cave levels separated by vertical differences of only a few meters may also be related to the Pleistocene climatic cycles. The subhorizontal parts of the Pec Cave are probably of late Early Pleistocene age (>0.99-1.07 Ma?). The two highest levels of the Plavecká jaskyňa developed during the early Middle Pleistocene (>600 ka). Fine-grained sediments in the passage at 225 m asl with normal magnetic polarity contain jarosite. The middle level of the Plavecká jaskyňa at 220 m asl was formed in the mid-Middle Pleistocene, while the lower and lowermost levels formed in the late Middle Pleistocene (>270 ka). The water table in the lowermost cave level probably dropped after the tectonic reactivation of the Podmalokarpatská zníženina Depression just in the front of a marginal horst structure of the Malé Karpaty Mountains. [ABSTRACT FROM AUTHOR]

Multiphase speleothem damage and passage collapse in Niedźwiedzia Cave (NE Bohemian Massif, Poland) were dated with U‐series methods, revealing five events: (1) 320–306 ka, (2) 253–236 ka, (3) 162–158 ka, (4) 132–135 ka, and (5) >21 ka. Events 1, 3 and 4 are robustly constrained, and events 2 and 5 are less certain. Although we cannot unambiguously exclude other agents (frost or gravity collapses), the most likely trigger of damage in the cave was an earthquake, which is supported by timing (the damage occurred independently from climatic conditions in cold and warm periods) and deformation style (damage to the ceiling and walls as well as the passage floor). We applied ground motion models to determine the probable seismic source size, which is most likely the Sudetic Marginal Fault ‐ one of the most pronounced tectonic structures in Central Europe. Located <20 km from the cave and with documented earthquakes of M > 6, the Sudetic Marginal Fault can produce peak ground acceleration values high enough to break speleothems. The other plausible seismic sources are faults in the Upper Nysa Kłodzka Graben located to the east and the Trzebieszowice‐Biela Fault. Although there are sparse historical data that would allow estimating linked seismic hazards, the <8 km distance between the cave and faults should suffice to destroy the speleothems. Niedźwiedzia Cave shielded environmental earthquake effects from erosion. This study shows the advantage of employing speleoseismology in moderate seismic regions, where earthquake effects are rarely preserved in the geological record. Key Points: In low to moderate seismic regions, where earthquake effects are rarely preserved in the geological record, caves can shield them from erosionSpeleoseismological research in Niedźwiedzia Cave revealed five events of cave damage between 320 and 21 kaBased on ground motion models, the probable seismic source of damage within the cave is the Sudetic Marginal Fault [ABSTRACT FROM AUTHOR]

The Ještěd Ridge (part of the Krkonoše-Jizera Crystalline Complex; northern part of the Bohemian Massif) hosts 20 known karst caves, which are developed in marbles of Devonian age. The caves are mostly relatively small and isolated, not connected into larger cave systems. The longest one, Západní (Jitravská) Cave, currently exceeds the length of 450 m. Majority of the known caves are shorter than 50 m. Formation of these cavities was initiated under morphological conditions different from those of today, in the pre-Quaternary. The caves are developed along two systems of regional faults, one striking NW-SE and the second striking SW-NE. One of the newly found caves, about 70 m long Dvoustovka Cave, was discovered in 2015 at an elevation of ca. 795 m a.s.l., close to the Ještěd ridgeline near the Pláně pod Ještědem site. The cave hosts several speleothem types including unusual, coarse-crystalline speleothems characterized by translucent calcite crystals up to 15 mm in size (so-called dogtooth spar). These speleothems developed in several small water pools located at different elevations within the cave. Fluid inclusions and C and O stable isotope studies (Table 1) do not support their deposition from thermal water and indicate formation from usual lowtemperature descending karst water. Fluid inclusions in calcite of dogtooth spar are single-phase, containing low-salinity water. The C and O isotope data lie in a range typical of usual low-temperature Quaternary speleothems of the area. The U-series dating (methods: spike addition; dissolution; chromatographic separation using TRU-resin; measurement on ICP-MS; results in Table 2) indicate an age of the coarse-crystalline speleothems fitting into the Eemian interglacial (118 ± 3 ka BP). Underground spaces of the Dvoustovka Cave are affected by numerous movements along cracks and rock collapses. While some of these movements occurred before the formation of the studied coarse-crystalline speleothems, majority of them are younger, related most probably to slope movements (mass wasting) during the last Glacial. The cave cannot keep larger stagnant pools of karst water today. [ABSTRACT FROM AUTHOR]

Cold Wind Cave, located at elevations ranging between 1,600 and 1,700 m a. s. l. in the main range of the Nízke Tatry Mountains (Slovakia), is linked in origin with the adjacent Dead Bats Cave. Together, these caves form a major cave system located within a narrow tectonic slice of Triassic sediments. Both caves have undergone complex multiphase development. A system of sub-horizontal cave levels characterized by large, tunnel-like corridors was formed during the Tertiary, when elevation differences surrounding the cave were less pronounced than today. The central part of the Nízke Tatry Mountains, together with the cave systems, was uplifted during the Neogene and Lower Pleistocene, which changed the drainage pattern of the area completely. The formation of numerous steep-sloped vadose channels and widespread cave roof frost shattering characterized cave development throughout the Quaternary. In the Cold Wind Cave, extensive accumulations of loose, morphologically variable crystal aggregates of secondary cave carbonate ranging in size between less than 1 mm to about 35 mm was found on the surface of fallen limestone blocks. Based on the C and O stable isotope compositions of the carbonate (δ13C: 0.72 to 6.34 ‰, δ18O: -22.61 to -13.68 ‰ V-PDB) and the negative relation between δ13C and δ18O, the carbonate crystal aggregates are interpreted as being cryogenic cave carbonate (CCC). Published models suggest the formation of CCC in slowly freezing water pools, probably on the surface of cave ice, most probably during transitions from stadials to interstadials. Though the formation of these carbonates is likely one of the youngest events in the sequence of formation of cave sediments of the studied caves, the 230Th/234U ages of three samples (79.7±2.3, 104.0±2.9, and 180.0±6.3 ka) are the oldest so far obtained for CCC in Central Europe. This is the first description of CCC formation in one cave during two glacial periods (Saalian and Weichselian). [ABSTRACT FROM AUTHOR]

The U-series dating indicates five episodes of flowstone growth in Brestovská Cave, namely: ca. 200 ka, ca. 128-88 ka, ca. 82-65 ka, ca. 64-50 ka, and during the Holocene. The age of flowstones and their spatial distribution within the cave prove that the upper storey of the cave was dewatered before 200 ka. At that time the lower storey also existed and was able to carry the whole water flowing through the cave. It suggests that 200 ka ago the water-table was at similar level as it is at present. Hence, one should accept that the valley bottom was then also at the present level. During at least a part of the MIS 6 the growth of speleothems was possible in the cave. It suggests that the cave was located outside the permafrost zone then. Between 50 ka and Holocene, Brestovská Cave was flooded by invasion waters originating from the melting of the Würm glacier; the water-table was additionally raised due to the blockage of a resurgence by glacifluvial sediments. The flooding event caused the destruction of older deposits, including speleothems, and deposition of fine-grained clastics on the cave walls. [ABSTRACT FROM AUTHOR]

Abstract The trans-boundary Slovak-Hungarian Domica–Baradla cave system (Slovak and Aggtelek karsts), >26 km in length, consists of evolution levels that have been formed in relation to the incision phases of the Jósva Valley. Existing opinions on the age of the well-known cave system have not been based on the dating of cave sediments deposited during older evolution phases. Previous U-series dating and the first paleomagnetic analyses of dripstones, flowstones and fine-grained allochthonous sediments identified only younger accumulative phases of the cave evolution in Late Pleistocene. Our cosmogenic nuclide dating (10Be and 26Al) of allochthonous fluvial gravels from the upper and lower levels of the Domica Cave (Slovakia) reveal much older evolution phases. Two burial ages at 3.47 ± 0.78 Ma and 2.94 ± 0.50 Ma show that the upper level of the cave system originated in, or before, the Middle Pliocene. Its younger accumulation phases (Early–Middle Pleistocene) are documented based on magnetostratigraphy and U-series dating of fine-grained sediments and flowstones. The Brunhes/Matuyama boundary (780 ka), Kamikatsura excursion (~900 ka), Santa Rosa excursion (~932 ka) and Jaramillo magnetozone (~1.001–1.069 Ma) were identified from the newly studied profile in the Suchá chodba Passage (the ages of flowstones in upper part of this profile are ~130 ka, 173 ka and 199 ka). In some places, several small older (paleokarst?) solutional phreatic cavities are cut by this cave level. The lower evolution level, located 12–18 m below the upper level, originated in the Early Pleistocene (the burial age of allochthonous fluvial gravels is 1.92 ± 0.25 Ma). Low pre-burial denudation rates (3.1–5.6 m/Ma) correspond with the slowdown or interruption of tectonic uplift of the area and the long-term stabilized erosion base level during the formation of these cave levels. Their origin was linked with the formation of large pediments, of which remnants are preserved on both sides of the Jósva Valley (Hungary). The pediments probably correlate to the 'foothill' (Middle Pliocene) and 'river-side' (Late Pliocene–Early Pleistocene) levels in the denudation chronology of the Western Carpathians. Highlights • Fluvially-modelled cave levels developed in relation to the formation of large pediments. • Combined use of absolute dating methods for the reconstruction of cave chronology. • The largest cave levels in the marginal part of the Western Carpathians formed in the Middle Pliocene and Early Pleistocene. • Paleo-denudation rates during the formation of cave levels are equivalent to low denudation rates of old cratons. • Refined denudation chronology of the Western Carpathians during the Middle Pliocene. [ABSTRACT FROM AUTHOR]