Acta CarsologicaOpen Journal SystemsJournal HelpUserUsername Password Remember meNotifications View SubscribeEnglish Slovensko (Slovenian)Journal ContentSearchSearch ScopeBrowse By Issue By Author By ...Title Other JournalsFont SizeMake font size smallerMake font size defaultMake font size larger Home About Login Register Search Current Archives Announcements Submit Old SiteHome > Vol 44, No 3 (2015) > AudraResearch frontiers in speleogenesis. Dominant processes, hydrogeological conditions and resulting cave patternsPhilippe Audra, Arthur N. PalmerDOI: https://doi.org/10.3986/ac.v44i3.1960AbstractSpeleogenesis is the development of well-organized cave systems by fluids moving through fissures of a soluble rock. Epigenic caves induced by biogenic CO2 soil production are dominant, whereas hypogenic caves resulting from uprising deep flow not directly connected to adjacent recharge areas appear to be more frequent than previously considered. The conceptual models of epigenic cave development moved from early models, through the “four-states model” involving fracture influence to explain deep loops, to the digital models demonstrating the adjustment of the main flow to the water table. The relationships with base level are complex and cave levels must be determined from the elevation of the vadose-phreatic transitions. Since flooding in the epiphreatic zone may be important, the top of the loops in the epiphreatic zone can be found significantly high above the base level. The term Paragenesis is used to describe the upward development of conduits as their lower parts fill with sediments. This process often records a general baselevel rise. Sediment influx is responsible for the regulation of long profiles by paragenesis and contributes to the evolution of profiles from looping to water table caves. Dating methods allow identification of the timing of cave level evolution. The term Ghost-rock karstification is used to describe a 2-phase process of speleogenesis, with a first phase of partial solution of rock along fractures in low gradient conditions leaving a porous matrix, the ghost-rock, then a second phase of mechanical removing of the ghost-rock mainly by turbulent flow in high gradient conditions opening the passages and forming maze caves. The first weathering phase can be related either to epigenic infiltration or to hypogenic upflow, especially in marginal areas of sedimentary basins. The vertical pattern of epigenic caves is mainly controlled by timing, geological structure, types of flow and base-level changes. We define several cave types as (1) juvenile, where they are perched above underlying aquicludes; (2) looping, where recharge varies greatly with time, to produce epiphreatic loops; (3) water-table caves where flow is regulated by a semi-pervious cover; and (4) caves in the equilibrium stage where flow is transmitted without significant flooding. Successive base-level drops caused by valley entrenchment make cave levels, whereas baselevel rise is defined in the frame of the Per ascensum Model of Speleogenesis (PAMS), where deep passages are flooded and drain through vauclusian springs. The PAMS can be active after any type of baselevel rise (transgression, fluvial aggradation, tectonic subsidence) and explains most of the deep phreatic cave systems except for hypogenic.
Palaeolithic cave art in Borneo Aubert, M; Setiawan, P; Oktaviana, A A ...
Nature (London),
12/2018, Volume:
564, Issue:
7735
Journal Article
Peer reviewed
Figurative cave paintings from the Indonesian island of Sulawesi date to at least 35,000 years ago (ka) and hand-stencil art from the same region has a minimum date of 40 ka
. Here we show that ...similar rock art was created during essentially the same time period on the adjacent island of Borneo. Uranium-series analysis of calcium carbonate deposits that overlie a large reddish-orange figurative painting of an animal at Lubang Jeriji Saléh-a limestone cave in East Kalimantan, Indonesian Borneo-yielded a minimum date of 40 ka, which to our knowledge is currently the oldest date for figurative artwork from anywhere in the world. In addition, two reddish-orange-coloured hand stencils from the same site each yielded a minimum uranium-series date of 37.2 ka, and a third hand stencil of the same hue has a maximum date of 51.8 ka. We also obtained uranium-series determinations for cave art motifs from Lubang Jeriji Saléh and three other East Kalimantan karst caves, which enable us to constrain the chronology of a distinct younger phase of Pleistocene rock art production in this region. Dark-purple hand stencils, some of which are decorated with intricate motifs, date to about 21-20 ka and a rare Pleistocene depiction of a human figure-also coloured dark purple-has a minimum date of 13.6 ka. Our findings show that cave painting appeared in eastern Borneo between 52 and 40 ka and that a new style of parietal art arose during the Last Glacial Maximum. It is now evident that a major Palaeolithic cave art province existed in the eastern extremity of continental Eurasia and in adjacent Wallacea from at least 40 ka until the Last Glacial Maximum, which has implications for understanding how early rock art traditions emerged, developed and spread in Pleistocene Southeast Asia and further afield.
This edited work presents an interdisciplinary exploration of the use of caves and rock shelters across Europe during the medieval period for a wide range of religious and spiritual purposes by ...Christian, Muslim, Pictish and non-denominational communities, at both regional and local levels.
Kahf Kharrat Najem Cave is a small cave in United Arab Emirates (UAE) that hosts a bat colony which is the source of guano deposits and peculiar centimeter-long yellowish stalactites. The mineralogy ...and geochemistry of these deposits were analyzed using powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopic microanalysis (EDX), scanning electron microscope (SEM), and stable isotope composition (δ^sup 13^C and δ^sup 15^N). Urea CO(NH^sub 2^)^sub 2^ was found to be the main compound of these stalactites, while allantoin C^sub 4^H^sub 6^N^sub 4^O^sub 3^ was found to be an accessory urea byproduct. This paper is the first to mention allantoin in a cave environment. We also identified rare sulfate minerals (aphthitalite, alunite) and phosphates that probably correspond to the archerite-biphosphammite series. The occurrence of these rare bat-related minerals is due to the extremely dry conditions in the cave, which accounts for the extraordinary preservation of the guano deposits and allows for the crystallization of these very soluble minerals.
Guano is a typical deposit found in caves derived from the excretions of bats and in minor cases of birds. These organic deposits decompose and form a series of acid fluids and gases that can ...interact with the minerals, sediments, and rocks present in the cave. Over sixty phosphates are known and described from caves, but guano decay also often leads to the formation of nitrates and sulfates. In this study twenty-two European caves were investigated for their guano-related secondary minerals. Using various analytical techniques, seventeen phosphates, along with one sulfate (gypsum), were recognized as secondary products of guano decay. Among those minerals, some are very rare and result from the interaction of guano leachates with clays, fluvial deposits, or pyrite. Some of these minerals are even found only in the studied caves (spheniscidite, robertsite). The most common minerals belong to the apatite group. The common mineral association present in fresh decaying guano is brushite-ardealite-gypsum, minerals that usually are not present in older deposits because of their higher solubility. Most minerals are in hydrated form because of the wet cave environment; however, some specific dry conditions may favor the presence of dehydrated minerals, such as berlinite, formed during guano combustion. Investigation on the acidity of guano piles shows pH values as low as 3.5 with an increase of acidity with age and depth. Finally, cave guano deposits should be better studied in the future because of their role in paleoenvironmental and paleoclimatic reconstructions and because it is important to better understand the origin of guano-related minerals, especially the phosphates and sulfates. Among all of the caves studied, Corona 'e sa Craba (Italy) and Domica-Baradla Cave (Slovakia-Hungary) are considered to be outstanding sites with respect to their phosphate mineralogy.
Hermannshohle is a show cave located near Kirchberg/Wechsel in Lower Austria. Together with three nearby and genetically connected caves, it forms the Hermannshohlen cave system (HHS). With a length ...of 5 km, the HHS is the longest cave in the Lower Austroalpine unit. It is arranged as an extreme three-dimensional maze on a ground area of 200 x 200 x 82 m. Speleothems are abundant in this cave and represent the focus of this study. Low carbon isotope values indicate the presence of a soil-covered catchment above the HHS during times of speleothem deposition. 28 samples were dated by the ^sup 230^Th/U-method and, in combination with palaeomagnetic data from a 5 m-high sediment profile, indicate multiple phases of sediment infill and erosion in the HHS. Although parts of the cave system are nowadays located at or below the level of the nearby Rams brook, they fell dry already at least 125 ka ago.
Cave hosted ice bodies have been reported to suffer significant mass loss worldwide. Although some successful achievements were reported recently to confirm the potential of stable isotope, pollen or ...trace element records in cave glaciers for climate and environmental reconstructions, these archives are still weakly studied. This brief paper is to be an invitation to the geoscience community to face this research need and devote more scientific attention to the complex research of cave ice deposits before accelerated melt will determine the complete loss of the unique palaeoenvironmental information stored in these deposits.
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Donors of Longmen is the first work in a Western language to recreate the history of the Longmen Grottoes, one of China's great stone sculpture treasure houses. Longmen, a UNESCO World Heritage site ...located near the old capital of Luoyang in modern Henan Province, consists of thousands of ancient cave chapels and shrines containing Buddhist icons of all sizes that were carved into the towering limestone cliffs from the fifth to the eighth century. Beyond its superb sculpture, Longmen also preserves thousands of engraved dedicatory inscriptions by its donors, who included emperors and empresses, aristocrats, court eunuchs, artisans, monks, nuns, lay societies, female palace officials, male civil and military officials, and ordinary lay believers. Based on wide reading of both Asian and Western-language scholarship and careful analysis of the architecture, epigraphy, and iconography of the site, Amy McNair provides a rich and detailed examination of the dynamics of faith, politics, and money at Longmen, beginning with the inception of the site at Guyang Grotto in 493 and concluding with the last major dated project, the forty-eight Amitabhas added to the Great Vairocana Image Shrine in 730. Believers sponsored statues and cave shrines as public acts of giving (dâna) and merit (karma) to generate social credit in the political realm and karmic merit in the spiritual. Although donors' choices of icons reveal the changes in Buddhist religious concerns over the 250-year life of the site, the discussions of expenditure in the dedicatory inscriptions reveal not only how much was spent, but also the rhetoric appropriate to the donor's station in life, gender, and the intended audience. McNair argues that donors made conscious decisions regarding the style of their sculptures--a lively interplay between native Chinese imagery and icons and styles of art from the Buddhist holy land of India--so as to imbue the images with meanings that were immediately comprehensible to their contemporaries. Through the her sensitive and well-informed exploration of Longmen's huge repository of remarkable early sculpture, McNair gives voice to a wide array of medieval believers, many of them traditionally excluded from history. Hers will be the definitive work on Longmen for years to come.
The Altai region of Siberia was inhabited for parts of the Pleistocene by at least two groups of archaic hominins-Denisovans and Neanderthals. Denisova Cave, uniquely, contains stratified deposits ...that preserve skeletal and genetic evidence of both hominins, artefacts made from stone and other materials, and a range of animal and plant remains. The previous site chronology is based largely on radiocarbon ages for fragments of bone and charcoal that are up to 50,000 years old; older ages of equivocal reliability have been estimated from thermoluminescence and palaeomagnetic analyses of sediments, and genetic analyses of hominin DNA. Here we describe the stratigraphic sequences in Denisova Cave, establish a chronology for the Pleistocene deposits and associated remains from optical dating of the cave sediments, and reconstruct the environmental context of hominin occupation of the site from around 300,000 to 20,000 years ago.
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