International, cooperative research in the Apuseni Mountains of western Romania

In May of 2006, nine American scientists and cavers from the Karst Research Group at the University of South Florida traveled to western Romania to attend and present at an international conference on records of climate change in caves in the historic Roman town of Baile Hurculane. The conference, co-sponsored by the “Emil Racoviţă” Speleological Institute of Romania and the Karst Waters Institute, drew more than 100 experts in the field of climate change and karst, and was a wonderful time spent alongside the thermal springs and Austro-Hungarian bathhouses nestled within the massive limestone canyon of the Cerna River. Following the conference and post-conference field trips in early June of 2006, six members of the American team joined with several Romanian colleagues to conduct paleoclimate research in the caves of the Apuseni Mountains of Transylvania. A follow-up trip in July of 2007 by a smaller research team completed the projects started the previous year. The NSS provided partial funding for the work in both 2006 and 2007 though an International Participation Grant. The Romanian Science Foundation and the Romanian Ministry of Education and Research provided much of the remaining funds

Constraining Holocene hydrological changes in the Carpathian–Balkan region using speleothem δ18O and pollen-based temperature reconstructions

Here we present a speleothem isotope record (POM2) from Ascunsă Cave (Romania) that provides new data on past climate changes in the Carpathian–Balkan region from 8.2 ka until the present. This paper describes an approach to constrain the effect of temperature changes on calcite δ18O values in stalagmite POM2 over the course of the middle Holocene (6–4 ka), and across the 8.2 and 3.2 ka rapid climate change events. Independent pollen temperature reconstructions are used to this purpose. The approach combines the temperature-dependent isotope fractionation of rain water during condensation and fractionation resulting from calcite precipitation at the given cave temperature. The only prior assumptions are that pollen-derived average annual temperature reflects average cave temperature, and that pollen-derived coldest and warmest month temperatures reflect the range of condensation temperatures of rain above the cave site. This approach constrains a range of values between which speleothem δ18O changes should be found if controlled only by surface temperature variations at the cave site. Deviations of the change in δ18Ocspel values from the calculated temperature-constrained range of change are interpreted towards large-scale variability of climate–hydrology. Following this approach, we show that an additional ∼0.6‰ enrichment of δ18Oc in the POM2 stalagmite was caused by changing hydrological patterns in SW Romania across the middle Holocene, most likely comprising local evaporation from the soil and an increase in Mediterranean moisture δ18O. Further, by extending the calculations to other speleothem records from around the entire Mediterranean basin, it appears that all eastern Mediterranean speleothems recorded a similar isotopic enrichment due to changing hydrology, whereas all changes recorded in speleothems from the western Mediterranean are fully explained by temperature variation alone. This highlights a different hydrological evolution between the two sides of the Mediterranean. Our results also demonstrate that during the 8.2 ka event, POM2 stable isotope data essentially fit the temperature-constrained isotopic variability. In the case of the 3.2 ka event, an additional climate-related hydrological factor is more evident. This implies a different rainfall pattern in the Southern Carpathian region during this event at the end of the Bronze Age

Datos preliminares sobre la mineralogía de los precipitados asociados a los respiradores y toberas existentes en la Cova des Pas de Vallgornera (Mallorca)

[cat] La Cova des Pas de Vallgornera, situada en la isla de Mallorca, es una cavidad excepcional por su desarrollo topográfico, presencia de espeleotemas y rasgos morfológicos. El conjunto de morfologías existentes ilustra el papel jugado por los distintos factores geológicos en su génesis. Contiene evidencias de procesos espeleogenéticos complejos, que incluyen a parte de la típica karstificación costera ligada a los procesos de corrosión en la zona de mezcla de aguas, una marcada recarga de aguas meteóricas juntamente con una posible recarga basal profunda de origen hipogénico, apoyada por la presencia de abundantes canales ascendentes de disolución, rising solutional channels en distintas zonas de la cavidad. Una serie de morfologías descritas como respiraderos (vents) muestran un conjunto de espeleotemas asociados como son las toberas (cave rims) y costras minerales. Las toberas se presentan alrededor de los agujeros y grietas presentes en el suelo de las galerías. Su génesis está relacionada con su posición en el nivel superior de la cavidad, por encima del nivel freático. La circulación de aire desde el nivel inferior (en contacto con el nivel freático que aporta la humedad al aire) al superior podría haber causado el desarrollo de estas morfologías. Parte de la composición química además de la variada mineralogía observada, apuntan a una influencia hipogénica en la génesis de las toberas y costras minerales relacionadas con los respiraderos. Aparte de los minerales carbonatados comunes presentes en las cuevas de Mallorca, se han identificado otros que en su gran mayoría son raros (monohidrocalcita, estroncianita, celestina, todorokita y varios minerales del grupo de las arcillas), u otros completamente inesperados (baritina, nordstrandita, maghmita y paralstonita). Debido a la monótona geología de la superficie alrededor de la cueva, creemos que fluidos ascendentes de origen hipogénico ricos, en Sr y Ba, reaccionaron con la roca encajante para formar este conjunto mineral único hasta el momento en el entorno de Mallorca.[eng] Located in the southern part of the island of Mallorca, on upper Miocene limestones, the Cova des Pas de Vallgornera is an exceptional coastal cave because of its length, presence of speleothems, and particular morphological features. Its morphological assemblage illustrates the key-role of geological factors in its genesis. It contains evidences of complex speleogenetic processes including besides the typical coastal karstification, a noticeable meteoric water recharge along with a possible basal, deep recharge of hypogenic origin. Related to the latter one there are some conspicuous upwards rising solutional channels. A series of morphologies interpreted as vents show associated and related speleothems such as crusts and cave rims. Rims occur around the lips of the holes and cracks on the galleries’ floor. The genesis of these speleothems closely relates to their location in the upper maze area of the cave, just above the water table level. Airflow from the lower level (in contact with the water table which supplies moisture to that air) to the upper level can cause the development of these rims. The chemical composition as well as a diverse mineralogy observed, point to a hypogenic influence into the crusts and cave rims genesis related to the vent morphologies. Apart from the common carbonate minerals present in the mallorcan cave environment, the vast majoriy are rare (monohydrocalcite, strontianite, celestite, siderite, todorokite, and various clay minerals) or completely unexpected (barite, nordstrandite, maghmite, and paralstonite). Given the monotonous surface geology around the cave we suspect that ascending Sr and Ba, hypogene solutions react with the host rock to form this unique mineral assemblage. Iron can be leached from surface or from the limestone

Late Quaternary Sea-level History: a Speleothem Perspective

Abstract not availabl

Searching for cold-adapted microorganisms in the underground glacier of Scarisoara Ice Cave, Romania

Scarisoara Ice Cave (Romania) hosts one of world’s largest and oldest underground glacier. While no studies were carried out on the existence of microorganisms in this cave’s ice block, our interest is to investigate the presence of microorganisms and their chronological distribution in the cave’s subterranean ice in relationship with past climatic changes. Samples were collected from ice layers of different age (from present to ~900 cal. yrs. BP), and the diversity of embedded microbial communities was assessed by classical cultivation and molecular techniques. The microorganisms from icesediments were cultivated at 4 °C and 15 °C, in the presence and absence of light. Epifluorescence microscopy analysis indicates the presence of autotrophic prokaryotes and eukaryotes in sunlightexposed ice and water samples. Total DNA was isolated from each ice sample and the bacterial and eukaryotic SSU-rRNA genes were amplified by PCR. The chemical composition and organic content of both deeply buried (>10 m inside the ice block) and surface (supra- glacial pond water) habitats were analyzed in relation to their age and organic composition. This study is the first to report on the presence of both prokaryotic and eukaryotic microorganisms in the subterranean ice block of Scarisoara Ice Cave, thriving in both organic-rich ice and clear ice layers. Phototrophic prokaryotes and eukaryotes were identified in sun-exposed recent ice. The composition of cold-adapted ice embedded microbiota varied with the habitat age and organic content, as resulting from dissimilarities in growth curve profiles at two different temperatures. The presence of bacteria and eukaryotes in all the analyzed samples was asserted by PCR amplification of SSU-rRNA gene fragments. These findings can be further used to reconstruct changes in the microbial diversity over the past approximately 5000 years, in correlation with climatic and environmental changes recorded by the ice block