Predstavljen je seznam jamskih simbolov, ki jih Mednarodna speleološka zveza priporoča pri risanju načrtov podzemnih jam. Seznam simbolov so leta 1999 izvolili delegati iz dvanajstih držav. Kjer je ...potrebno, je poleg simbola še krajša razlaga. V prispevku je na kratko predstavljena tudi podkomisija za topografijo pri Mednarodni speleološki zvezi. A set of cave symbols used for underground mapping has been voted by national delegates of 12 countries in 1999. This symbol set is shown and, when necessary, explained. The UIS subcommission on topography is briefly presented and its aims outlined.
Deuterium (δD) and oxygen (δ18O) isotopes are powerful tracers of the hydrological cycle and have been extensively used for paleoclimate reconstructions as they can provide information on past ...precipitation, temperature and atmospheric circulation. More recently, the use of 17Oexcess derived from precise measurement of δ17O and δ18O gives new and additional insights in tracing the hydrological cycle whereas uncertainties surround this proxy. However, 17Oexcess could provide additional information on the atmospheric conditions at the moisture source as well as about fractionations associated with transport and site processes. In this paper we trace water stable isotopes (δD, δ17O and δ18O) along their path from precipitation to cave drip water and finally to speleothem fluid inclusions for Milandre cave in northwestern Switzerland. A two year-long daily resolved precipitation isotope record close to the cave site is compared to collected cave drip water (3 months average resolution) and fluid inclusions of modern and Holocene stalagmites. Amount weighted mean δD, δ18O and δ17O are −71.0‰, −9.9‰, −5.2‰ for precipitation, −60.3‰, −8.7‰, −4.6‰ for cave drip water and −61.3‰, −8.3‰, −4.7‰ for recent fluid inclusions respectively. Second order parameters have also been derived in precipitation and drip water and present similar values with 18 per meg for 17Oexcess whereas d-excess is 1.5‰ more negative in drip water. Furthermore, the atmospheric signal is shifted towards enriched values in the drip water and fluid inclusions (Δ of ∼ + 10‰ for δD). The isotopic composition of cave drip water exhibits a weak seasonal signal which is shifted by around 8–10 months (groundwater residence time) when compared to the precipitation. Moreover, we carried out the first δ17O measurement in speleothem fluid inclusions, as well as the first comparison of the δ17O behaviour from the meteoric water to the fluid inclusions entrapment in speleothems. This study on precipitation, drip water and fluid inclusions will be used as a speleothem proxy calibration for Milandre cave in order to reconstruct paleotemperatures and moisture source variations for Western Central Europe.
•First measurements of δ17O in speleothem fluid inclusions.•Triple isotope (δD, δ17O, δ18O) compared for the first time in precipitation, drip water and speleothem fluid inclusions.•New insights through 17Oexcess geochemistry in a cave environment and for precipitation.•Isotope monitoring as a prerequisite for paleoclimate reconstruction for Milandre Cave speleothems.
Karstic caves are created by water eroding and corroding rocks that can be dissolved. Since both the spring areas of caves (normally at the valley bottom) as well as the recharge is controlled by ...superficial processes, the morphology of the cave bears strong links to these influences. Lowering of local base levels promotes the development of horizontal phreatic cave passages at progressively lower elevations, resulting in the formation of multi-level karst systems. Upon the next lowering of base level, these upper systems become fossilized, and sediment trapped within them may remain preserved for millions of years. Dating these sediments gives clues regarding the time when the passages were last active, and thus may yield age information for old valley floors. The present paper presents cosmogenic nuclide datings of twelve samples from eight caves in the central part of the Northern Calcareous Alps of Austria. Besides three samples that gave no results, most of the obtained ages are at the Mio-Pliocene boundary or within the Pliocene, as was expected before sampling. No multi-level caves could be sampled at different elevations, thus, the obtained valley deepening rates are averages between the age of sediment deposition and the present-day valley floor. However, the valley deepening rates of 0.12 to 0.21 km/Ma are in accordance to previous findings and corroborate a comparatively slow evolution of base level lowering in the Eastern Alps compared to the fast (Late Quaternary) evolution in the Central and Western Alps.
We report the first incision rates derived from burial ages of cave sediments from the Mur river catchment at the eastern margin of the Eastern Alps. At the transition zone between the Alpine orogen ...and the Pannonian basin, this river passes through the Paleozoic of Graz — a region of karstifiable rocks called the Central Styrian Karst. This river dissects the study area in a north–south direction and has left behind an abundance of caves. These caves can be grouped into several distinct levels according to their elevation above the present fluvial base level. Age estimates of abandoned cave levels are constrained by dating fluvial sediments washed into caves during the waning stages of speleogenesis with the terrestrial cosmogenic nuclide method. These ages and the elevations of the cave levels relative to the current valley floor are used to infer a very complex history of 4millionyears of water table position, influenced by the entrenchment and aggradation of the Mur river. We observe rather low rates of bedrock incision over the last 4Ma (in the order of 0.1mm/y) with an e-folding decrease in this trend to lower rates at younger times. We relate this incision history to a tectonic setting where an increase of drainage area of the Mur river due to stream piracy in Late Miocene to Pliocene times is linked to surface uplift. The later decrease in valley lowering rates is attributed to the rise of the base level related to aggradation of sediments within the valley. Sediment transport through the valley from the upstream section of the Mur river limited the erosional potential of the river to a transport limited state at the later stages of the incision history.
Raponzolo is a paleo-phreatic cave explored in 2011 in the Brenta Dolomites (Trentino, Italy), at the remarkable altitude of 2,560 m a.s.l. Differently to all other caves of the area, it hosts ...well-cemented fine to medium sands of granitic-metamorphic composition. The composition suggests a sediment source from the Adamello and Tonale Unit, separated from the Brenta by one of the most important tectonic lineaments of the Alps (Giudicarie Line). The fine-sand sediment was sampled to determine burial time and thus a minimum age of the cave. Cosmogenic isotopes (
26
Al and
10
Be) in quartz grains allowed to estimate a minimum burial age of 5.25 Ma based on the mean sediment transport time at the surface and infer original altitude of the catchment area. Detrital apatite fission-track (AFT) and U-Pb dating on zircons provide information on the source, both from a regional and altitude (exhumation) perspective. Two populations of detrital AFT ages center at 17 (−2.3 + 2.6) Ma and 23 (−3.3 + 3.9) Ma, whereas the main detrital zircon U-Pb age populations are younger than 40 Ma. These correspond to intrusive and metamorphic sources nowadays outcropping exclusively above 2,200–2,300 m a.s.l. in Northern Adamello and Tonale. The results point to a late Miocene erosion and infilling of the cave by allochtonous sediments, with important implications on the timing of cave speleogenesis, as well as the paleogeographical connection, tectonic evolution and uplift of different structural units of the Alps. The roundness and the well sorted size of the quartz grains suggest a fluvial or aeolian origin, possibly recycled by glacial activity related to cold events reported in high latitude areas of the world at 5.75 and 5.51 Ma. These glacial phases have never been documented before in the Alps. This information confirms that the valleys dividing these geological units were not yet deeply entrenched during the onset of the Messinian Salinity Crisis (5.6–5.5 Ma), allowing an efficient transport of sediments across major tectonic lineaments of the Alps. This study shows the potential of cave sediments to provide information not only on the age of speleogenesis but also on the paleogeography of a wide area of the Alps during the late Miocene.
Kozmični žarki povzročajo nastanek kozmogenih nuklidov na površini zemlje in tik pod njo. Za datiranje jamskih sedimentov sta posebej pomembna 10Be in 26Al, ki nastajata v kremenu. Ko je kamen na ...površini in izpostavljen kozmičnemu sevanju, nastajata v stalnem razmerju. Ko ga zanese v podzemlje, se tvorba kozmogenih nuklidov ustavi, nadaljuje pa se njihov radioaktivni razpad. Ker 26 Al razpada hitreje, lahko iz razmerja med njima izračunamo čas, ki je potekel odkar je kremen pod zemljo. Metodo lahko uporabimo na sedimentih, ki so pokopani oziroma v jami med 0.1 in 5 milijoni let. Na ta način lahko v idealnih primerih izračunamo hitrost vrezovanja dolin. Z opisano metodo smo določili starost najstarejših delov sistema Siebenhengste v Švici. Najstarejši sediment je star 4.4 ± 0.6 Ma in nakazuje, da je na tem območju potekalo zakrasevanje že v pliocenu. Cosmic rays produce nuclides at and near the Earthʼs surface. 10Be and 26Al in quartz are of particular interest for dating cave sediments. These two nuclides are produced at the surface at a fixed ratio. If the quartz is carried from the surface into a cave, the sediment is shielded from additional cosmogenic nuclide production, and the inherited 10Be and 26Al decay radioactively. Because 26Al decays more rapidly than 10Be, the ratio of these two nuclides indicates the time since the sediment was washed underground. The burial dating method can be applied to sediments in the age range of approximately 0.1 to 5 Ma. In ideal cases, we get information about valley lowering rates. If the provenance of the sediment is known, averaged erosion rates of the source area can be estimated. The oldest cave phases of the Siebenhengste system, Switzerland, were dated using cosmogenic nuclides. The oldest sediment is 4.4 ± 0.6 Ma and thus indicates Pliocene karstification of the Siebenhengste.
The present publication focuses on the study of caves in northern and central Switzerland in order to detect and date historical earthquakes and active tectonic displacements by investigations of ...broken and resealed or displaced speleothems datable by U/Th and 14C. While it can be shown that these methods are potentially suitable, the ages obtained are often beyond the range of historically recorded earthquakes, and it cannot be proved that the observed and dated events are related to a seismic event. Particularly this is true for the caves in central Switzerland, where most ages in the Melchsee-Frutt region were beyond the limits of the U/Th method, or of late Pleistocene age in the Siebenhengste-Hohgant region. A direct comparison with known historical (or prehistoric) earthquakes was not possible. In contrast to central Switzerland, the results in the Basle region of northern Switzerland indicates cave and speleothem damages in one cave within the epicentral area of the 1356 Basle earthquake. 14C datings allowed to directly relate the speleothem damages to this M 6.9 earthquake. Further dating results from caves in northern Switzerland on speleothems and organic material in cave deposits supplied ages which indicate older events not related to the historical Basle earthquake. The detection of active fault displacements and prehistoric strong earthquakes can only be achieved by a very careful deciphering of the palaeo-environmental records and many more age determinations which allow to separate active tectonic displacements and seismic events from other events not related to tectonics, i.e. glaciations, creep of sediments, catastrophic floods etc.
29 year old rock paintings in the Alpine karren field of Innerbergli (Siebenhengste, Switzerland) prevented the underlying rock from corrosion, while the surface nearby was corroded. Measurement of ...the steps indicates an average recent corrosion rate of 0.014 (±0.007) mm/a. This denudation rate is very similar to those observed in other comparable places and with other means.
The sedimentary deposits from Cioclovina Uscată Cave yielded numerous paleontological, anthropological and mineralogical findings. However, until now, a study of the sediments and their depositional ...features and environment had not been conducted. Here, we present a complete study of the sediments within the
Main Gallery
with the purpose of documenting their origin, depositional mode and processes, and direction of the paleodrainages. Seventeen sedimentary profiles were mapped and analyzed. A complete map was drawn, based on the lithological description, laboratory analyses, and the exact position of the profiles in the sedimentary deposit and their location along the gallery. Although the deposition mode of the sediments is very complex, the distribution of three main complexes (silt, sand and pebbles) can be clearly distinguished, indicating a typical cave channel lithofacies. We recognize seven stages in the evolution of the cave; the third one indicates a sudden change in the climatic conditions at the surface.
A cave is a natural void in the rock. Therefore, a cave in itself cannot be dated, and one has to resort to datable sediments to get ideas about the age of the void itself. The problem then is that ...it is never very certain that the obtained age really is coincident with the true age of the cave. Here, we present the use of a method which couples sedimentary and morphologic information to get a relative chronology of events. Datings within this relative chronology can be used for assessing ages of forms, processes, and sediments, and the obtained dates also fix some milestones within the chronology, which then can be used to retrace, among other things, paleoclimatic variations. For many cave systems, the dating limits of the most widely used U/Th method on speleothems are too low (350 to max. 700 ka) to get ages that inform us about the age of the cave. The recent use of cosmogenic nuclides on quartz-containing sediment permits to push the datable range back to 5 Ma. While the theoretical background is explained elsewhere (Granger, this volume), we concentrate on the Siebenhengste example (Switzerland)
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