|Celní jeskyně v Horních Albeřicích v Krkonoších|
|Celní jeskyně cave at Horní Albeřice in the Krkonoše Mts|
|zarovnané stropy, jeskynní sediment, tektonika, antropogenní vliv, geneze|
|flat solution roof, cave sediments, tectonicts, anthropogenic impact, evolution|
Práce shrnuje výsledky průzkumu a výzkumu jeskyně od roku 1974 do roku 2015, včetně vyhodnocení archivních materiálů. Jeskyně je dlouhá 119 m s denivelací –21,4 m. Podstatná část chodeb je nepravidelného oválného průřezu s množstvím stropních kapes, kanálů a reliktů zarovnaných stropů. Prostory jsou závislé především na poruchách směru zhruba Z–V se sklonem 20 až 40° k jihu. Část prostor vyplňuje prachovitý až prachovito-jílovitý sediment s podílem křemene a muskovitu. V nejnižším místě vzniká jezero o hloubce několika metrů závislé na dešťových srážkách. Jeskyně má v zimním období dynamické proudění vzduchu směrem dovnitř. Vývoj probíhal ve třech fázích. Nejprve došlo ke vzniku izolovaných dutin, jejich postupnému propojení a následnému vyplachování sedimentů. Vchod byl odkryt při těžbě v lomu a byl zde pravděpodobně odlámán větší jeskynní systém. Do jeskyně napadalo značné množství lomové sutě a některé prostory byly částečně pozměněny při speleologických pracích.
Results of research and exploration in the cave from 1974 to 2015 are summarized including the evaluation of archival data. The cave is 119 m long with an altitude difference of –21.4 m. A substantial part of the corridors have an irregular, oval cross section, with many ceiling pockets and channels, and with relicts of flat solution roofs. Cave spaces are controlled primarily by fractures approx. in a W–E direction and dipping at 20–40° to the South. Some of the spaces are filled with silt to silt/clay-dominated sediment with quartz and muscovite. Several meters deep lake floods the cave bottom oscillating according to the precipitation. A dynamic air flow into the cave is observed in winter. Three stages of cave development are distinguished. Isolated cavities were formed first, which later became interconnected, and their sedimentary fill was subsequently removed. The cave entrance was discovered during quarrying. A rather large cave system has been probably removed by limestone exploitation in the quarry. The cave became filled with considerable amounts of quarry rubble, and some cave spaces have been partly altered during speleological exploration.
|The Celní jeskyně cave is situated in the Celní lom quarry at Horní Albeřice in the eastern Krkonoše Mts. Its entrance is located in the SE corner of the quarry at an altitude of 787 m. Bands of crystalline rocks strike mostly north – south, dipping steeply at 60–90° to theeast and west. The carbonate band containing the Celní lom quarry is intercalated in chlorite-sericite phyllites, being terminated by a steeply dipping NE – SW fault in the north. The cave is developed in crystalline limestones with a local dolomite admixture and with thin lenses of calcitic phyllites. The cave is 119 m long, with an altitude difference of 21.4 m. Speleological works have been conducted here since 1974 with varying intensity. Altogether, 540 man-days of work have been spent here. The artificially exposed entrance to the Celní jeskyně cave is located on a bench of the quarry, being followed by a narrow passage. This passage opens into a round opening of a shaft, which passes downwards to an elongate vertical room. The bottom of the room is fully covered by rubble from the quarry. A side passage further south (Králičí chodba – Rabbit Passage) reveals silt- and clay-dominated sediment beneath the quarry rubble. A vertically elongated, artificially excavated cavity, the Střílená šachta shaft (Blasted Shaft), continues towards the NW, opening into the Transportní Dome through a narrow hole. Transportní dóm dome is a dome-like room with numerous pockets in the ceiling and with flat solution roofs (Laugdecken). The bottom of the dome is covered by silt-dominated sediment. Severní chodba (Northern Passage) extends from the Transportní dóm dome towards the north. The Studna (Well) abyss extends downwards. Severní chodba passage is a steeply rising, low and broad passage. At its end, it forks and lowers to impassable heights. It is directed towards the Krakonošova jeskyně cave. Flat solution roofs are preserved at several sites in the Severní chodba passage. The passage lacks, with subtle exceptions, any sedimentary fill. The Studna abyss is of relatively regular, elliptical cross sections. Its course is not vertical. The abys opens into the largest dome, the Vlhký dóm dome (Moist Dome). In this dome, an excavated test pit failed to reach the rocky bottom. The fill of the Vlhký dóm dome is formed by a variety of laminated and stratified silt-dominated and silt- and clay-dominated sediments. The ceiling of the Vlhký dóm dome shows an extremely complex relief (ceiling pockets, channels, flat solution roofs). All water from the Celní šachta shaft, Severní chodba passage and the Studna abyss disappears under the western wall of the dome, approximately beneath a narrow passage. Cave spaces are controlled primarily by fractures striking approximately W – E and dipping south at an angle of 20–40°. Vertical rooms are controlled by steep fractures, also striking approx. W–E. The character of the spaces is not substantially affected by the presence of numerous quartz lenses or dolomite - rich portions in the carbonate rock. Most corridors are of irregular, oval cross sections. Their ceilings are very uneven, with a number of pockets and channel mouths. Flat solution roofs are perfectly preserved at several sites. Flowstone decorations are missing, including their embryonic stages. Detrital sediments are represented by silt- to silt/clay-dominated sediment with a proportion of quartz and muscovite. The sediment also contains dispersed organic matter. A lake several meters deep occurs on the cave bottom, strongly depending on the amount of precipitation. It disappears in very dry seasons. This water comes from the surface, as confirmed by conductivity; no karst water was confirmed. Discrete issues from this cave are probably located at the western limit of the carbonate body, at the boundary with phyllites. Transverse drainage of the carbonate body takes place here. Celní jeskyně cave is a markedly dynamic cave in winter. Inflow of cold air into the cave affects temperatures many metres to the inside of the cave system. In this period, temperatures in the cave drop slightly below the freezing point as far as to the Transportní dóm dome. In summer time, the flow reverses, but the warm air from the surface has little affect on temperatures in the cave . Individuals of the greater mouse-eared bat (Myotis myotis) and the northern bat (Eptesicus nilssonii) live in the cave in winter. The entrance to the cave was uncovered during quarrying. Most probably, a rather large cave systém has been quarried away, which was interconnected with the currently preserved system. The quarrying was accompanied by washing of sedimentary fill and by falling of quarry rubble into the Stará jeskyně cave (Old Cave) and the Studna abyss. Prominent anthropogenic influences also included widening of the impassable vertical cavity (which, however, resulted in the discovery of a substantial part of the presently known cave system) and the subsequent opening of the Celní šachta shaft, removal of quarry rubble and excavations in the sediments. Around 60 m3 of quarry rubble and sediments have been removed from the cave. Three distinct stages of cave development can be distinguished. First, isolated or sparsely interconnected cavities of irregular shape were formed. These became filled with autochthonous material and water. After gradual mutual interconnection of the cavities, washing of sediments to the level of the Transportní dóm dome occurred. In the third stage, narrow vertical cavities along joints widened and interconnected. The sediments were washed into other, as yet undisclosed, parts of the cave below the level of the presently known bottom.|
|Plán a rozvinutý vertikální řez Celní jeskyně||Jiný typ přílohy||Download|