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Full-Text Articles in Earth Sciences
Cryogenic Ridges: A New Speleothem Type, Bogdan P. Onac, Daniel M. Cleary, Oana A. Dumitru, Victor J. Polyak, Ioan Povara, Jonathan G. Wynn, Yemane Asmerom
Cryogenic Ridges: A New Speleothem Type, Bogdan P. Onac, Daniel M. Cleary, Oana A. Dumitru, Victor J. Polyak, Ioan Povara, Jonathan G. Wynn, Yemane Asmerom
International Journal of Speleology
Cryogenic cave carbonates have been described from several formerly or presently glaciated karst caves. In most of these occurrences, they precipitated as loose grains or aggregates with various morphologies and sizes. Here, we report on a new speleothem type (cryogenic ridges) identified in Sohodoalele Mici Cave (SW Romania) within a large chamber near the entrance shaft. This study was motivated by the presence of a network of calcite ridges over the stalactites’ surface and by the observation that during winter, these speleothems are covered by a thin ice layer. The higher δ18O (−3.5 to –1‰) and …
Petrographical And Geochemical Changes In Bosnian Stalagmites And Their Palaeo-Environmental Significance, Veronica Chiarini, Isabelle Couchoud, Russell Drysdale, Petra Bajo, Simone Milanolo, Silvia Frisia, Alan Greig, John Hellstrom, Jo De Waele
Petrographical And Geochemical Changes In Bosnian Stalagmites And Their Palaeo-Environmental Significance, Veronica Chiarini, Isabelle Couchoud, Russell Drysdale, Petra Bajo, Simone Milanolo, Silvia Frisia, Alan Greig, John Hellstrom, Jo De Waele
International Journal of Speleology
Detailed petrographic observations have been coupled with trace element and δ13C - δ18O analyses in order to investigate their dynamics in two Holocene Bosnian speleothems. The potential of this multiproxy approach in providing a means to extract palaeo-environmental information from stalagmites whose stable isotope signals are noisy and without obvious trends has been tested. The studied stalagmites are mostly characterized by columnar microcrystalline fabric. At the sub-millimetre scale of lamination, different microcrystalline columnar sub-types (open and closed) have been detected and classified on the basis of the observed porosity and the crystallite size. The presence of …
Groundwater Geochemistry Observations In Littoral Caves Of Mallorca (Western Mediterranean): Implications For Deposition Of Phreatic Overgrowths On Speleothems, Liana M. Boop, Bogdan P. Onac, Jonathan G. Wynn, Joan J. Fornós, Marta Rodríguez-Homar, Antoni Merino
Groundwater Geochemistry Observations In Littoral Caves Of Mallorca (Western Mediterranean): Implications For Deposition Of Phreatic Overgrowths On Speleothems, Liana M. Boop, Bogdan P. Onac, Jonathan G. Wynn, Joan J. Fornós, Marta Rodríguez-Homar, Antoni Merino
International Journal of Speleology
Phreatic overgrowths on speleothems (POS) precipitate at the air-water interface in the littoral caves of Mallorca, Spain. Mainly composed of calcite, aragonite POS are also observed in specific locations. To characterize the geochemical environment of the brackish upper water column, water samples and salinity values were collected from water profiles (0-2.9 m) in April 2012 and March 2013 near aragonite POS in Cova des Pas de Vallgornera and calcite POS in Coves del Drac (hereafter, Vallgornera and Drac). Degassing of CO2 from the water was evidenced by the existence of lower dissolved inorganic carbon (DIC) concentration and enriched δ …
A New Foodweb Based On Microbes In Calcitic Caves: The Cansiliella (Beetles) Case In Northern Italy, Maurizio G. Paoletti, Mattia Beggio, Angelo Leandro Dreon, Alberto Pamio, Tiziano Gomiero, Mauro Brilli, Luca Dorigo, Giuseppe Concheri, Andrea Squartini, Annette Summers Engel
A New Foodweb Based On Microbes In Calcitic Caves: The Cansiliella (Beetles) Case In Northern Italy, Maurizio G. Paoletti, Mattia Beggio, Angelo Leandro Dreon, Alberto Pamio, Tiziano Gomiero, Mauro Brilli, Luca Dorigo, Giuseppe Concheri, Andrea Squartini, Annette Summers Engel
International Journal of Speleology
The troglobitic beetle, Cansiliella servadeii percolating water on moonmilk, a speleothem formation in Grotta della Foos, Italy. Results from analyses of stable isotopes of carbon and nitrogen suggest that acquires and assimilates dissolved allochthonous organic carbon, inorganic nitrogen, and possibly phosphorus and other nutrients from the microbial fauna associated with moonmilk.
Revisiting Three Minerals From Cioclovina Cave (Romania), Bogdan P. Onac, Herta S. Effenberger, Nathan C. Collins, Joe B. Kearns, Radu C. Breban
Revisiting Three Minerals From Cioclovina Cave (Romania), Bogdan P. Onac, Herta S. Effenberger, Nathan C. Collins, Joe B. Kearns, Radu C. Breban
International Journal of Speleology
Cioclovina Cave in Romania’s Southern Carpathians is a world-renowned cave site for its paleontological, anthropological, and mineralogical (type locality of ardealite) findings. To date, over 25 mineral species have been documented, some unusual for a cave environment. This paper presents details on the occurrence of collinsite [Ca2(Mg,Fe2+)(PO4)2·2H2O], atacamite [Cu22+Cl(OH)3], and kröhnkite [Na2Cu2+(SO4)2·2H2O] based on single-crystal X-ray diffraction, electron microprobe, stable isotope analyses, and scanning electron microscope imaging. This is the first reported occurrence of kröhnkite …
Age Frequency Distribution And Revised Stable Isotope Curves For New Zealand Speleothems: Palaeoclimatic Implications, Paul W. Williams, Helen L. Neil, Jian-Xin Zhao
Age Frequency Distribution And Revised Stable Isotope Curves For New Zealand Speleothems: Palaeoclimatic Implications, Paul W. Williams, Helen L. Neil, Jian-Xin Zhao
International Journal of Speleology
The occurrence of speleothems in New Zealand with reversed magnetism indicates that secondary calcite deposition in caves has occurred for more than 780 thousand years (ka). 394 uranium-series dates on 148 speleothems show that such deposition has taken place somewhere in the country with little interruption for more than 500 ka. A relative probability distribution of speleothem ages indicates that most growth occurred in mild, moist interglacial and interstadial intervals, a conclusion reinforced by comparing peaks and troughs in the distribution with time series curves of speleothem δ18O and δ13C values. The stable isotope time series …
Modern C, O, And H Isotope Composition Of Speleothem And Dripwater From Modrič Cave, Eastern Adriatic Coast (Croatia), Maša Surić, Zvjezdana Roller-Lutz, Magda Mandić, Ines Krajcar Bronić, Mladen Juračić
Modern C, O, And H Isotope Composition Of Speleothem And Dripwater From Modrič Cave, Eastern Adriatic Coast (Croatia), Maša Surić, Zvjezdana Roller-Lutz, Magda Mandić, Ines Krajcar Bronić, Mladen Juračić
International Journal of Speleology
Modrič Cave is a shallow horizontal cave situated in the middle of the eastern Adriatic coast (Croatia). The cave entrance is located 120 m from the coast at an altitude of 32 m above sea level, and due to its position on the SW slope of the Dinaridic mountain range, a Mediterranean climatic influence is dominant. Due to the stable environmental conditions [(15.6 ± 0.1) °C] Modrič Cave was recognized as a potential site for detailed palaeoclimatic studies. Isotope analyses of modern carbonate speleothems, rain and dripwater were conducted in order to evaluate the isotopic equilibrium conditions. The δ18O composition …
Speleothems As Indicators Of Wet And Dry Periods, Ian John Fairchild, Emily Anne Mcmillan
Speleothems As Indicators Of Wet And Dry Periods, Ian John Fairchild, Emily Anne Mcmillan
International Journal of Speleology
Calcareous speleothems provide a record of dripwater composition which in turn is a function of climatic conditions. The historical focus of speleothem palaeoclimate studies has been on the derivation of palaeotemperatures through oxygen isotope studies. However, it is now realized that water availability is a more generally important control on their characteristics. Growth rate and growth morphology in principle should give rise to recognizable changes at low flow. However, accidental plumbing effects during aquifer evolution, can also lead to variations in water supply and it is not easy to distinguish these effects. In areas where there is a strong amount …