RT Journal Article
T1 Porosity and hydric behavior of typical calcite microfabrics in stalagmites
A1 Muñoz García, Mercedes
A1 López Arce, Paula
A1 Fernández Valle, Mª Encarnación
A1 Martín Chivelet, Javier
A1 Fort González, Rafael
AB Petrophysical techniques commonly used for material characterization are applied for the first time tospeleothem samples to investigate the porosity and hydric behavior of calcite stalagmites used in paleoclimatology.These techniques allow the determination of the stalagmites' potential to undergo diagenetic transformationswhen substantial changes in drip waters occur in the cave environment. The petrophysicaltechniques include water absorption under vacuum and by capillarity, nuclear magnetic resonance, environmentalscanning electron microscopy, and mercury intrusion porosimetry. The studied samples comprise fivecommon calcite microfabrics, which have markedly different porosities and hydric behaviors and, as a consequence,different sensibilities to diagenetic processes related to the influx of water. The experiments showthat stalagmites can behave as complex, small-scale hydrological systems and that the circulation of waterthrough them by complex nets of interconnected pores might be common. As the circulation of water favorsdiagenetic transformations that involve geochemical and isotopic changes, the characterization of flow patternsis key for outlining areas that are susceptible to such modifications, which is critical to paleoclimaticstudies that are based on speleothems because geochemical and stable isotopic data are used as paleoenvironmentalproxies and absolute ages are obtained by using radioactive isotope ratios. These potential modificationsalso have obvious implications for studies based on fluid inclusions in speleothems.The integrated methodology, which uses primarily non-destructive techniques, shows a high potential forcharacterization of any type of speleothem and other continental carbonates such as tufas or sinters.
PB Elsevier
SN 0037-0738
YR 2012
FD 2012
LK https://hdl.handle.net/20.500.14352/43667
UL https://hdl.handle.net/20.500.14352/43667
LA eng
DS Docta Complutense
RD 28 abr 2024