Naslov
Stable Isotope Composition of Recent Cave Calcite Precipitates and its Relation to Dic in Drip Water From Postojna Cave, Slovenia

Autori
Mandić, Magda ; Krajcar Bronić, Ines ; Mihevc Andrej ; Leis, Albrecht

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Abstracts / Otoničar, Bojan ; Gostinčar, Petra ; Gabrovšek, Franci - Postojna : Znanstvenoraziskovalni center SAZU, Inštitut za raziskovanje krasa ZRC SAZU = Karst Research Institute at ZRC SAZU, 2013, 88-88

Skup
21st International Karstological School "Classical Karst" : Hypogene Speleogenesis (between theory and reality...)

Mjesto i datum
Postojna, Slovenija, 10.06.2013. - 14.06.2013

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
speleothems; monitoring; cave environment; carbonate precipitates PCP

Sažetak
Modern approach to the application of stalagmites for paleoclimate investigation recommends first studies of younger actively growing samples as well as cave drip water and cave environment monitoring undertaken for at least one climatic year. In the period from March 2010 to April 2011 such program has been performed in Postojna Cave. Environmental parameters (air and water temperature, pCO2 and geochemical parameters of drip water) have been monitored and stable isotopic composition (13C and 18O) of water and recent (soda straw and carbonate precipitated on watch glasses) has been determined, as well as stable isotopic composition of old carbonates. Monitoring has been performed on nine locations along the longitudinal profile of Postojna cave. Locations were chosen in order to cover different conditions of cave environment. Drip rate has been measured at each site. Glass plates were exposed for eight months at each location for recent carbonate precipitate sampling. The analysis of carbon (13C) and oxygen (18O) isotope ratios from cave drip water and fresh calcite precipitates from watch glasses has been done. Here we present the obtained results. The 13C values of carbonates precipitated on watch glasses are close to the corresponding 13CDIC values (≈-12 to -13 ‰). The values of 13C for “soda straws” vary from -7.84 ‰ to -10.58 ‰. The 13C of DIC and carbonates precipitated on watch glasses at location 05 – Podrti kapnik, -9.90 ‰ and -9.95 ‰, respectively, differ significantly from the corresponding data at other locations. The reason of such behavior could be in assumed prior calcite precipitation (PCP). The highest 18O value of soda straw samples is -4.84 ‰ and the lowest is -7.84 ‰. The 18O values of carbonates precipitated on watch glasses range from -3.07 ‰ to -4.67 ‰. The 18O values of carbonates on watch glasses are therefore more positive/less negative than 18O of “soda straws”.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Geologija

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