Uranium-series dating of gypsum speleothems: methodology and examples

Authors

Laura Sanna, Bergen University
Francisco Saez
Siri Simonsen, University of Oslo
Silviu Constantin, Bergen University
José-Maria Calaforra, University of Almeria
Paolo Forti, University of Bologna
Stein-Erik Lauritzen, Bergen UniversityFollow

Abstract

The analytical problems of dating gypsum speleothems with the U-series technique are reviewed. Gypsum speleothems are, in general, very low in U content, challenging the limits of detection methods. Various approaches to dissolving gypsum and isolation of actinides from the matrix include ion-pairing dissolution with magnesium salts and using nitric acid. The most precise dating technique is Thermal Ionization Mass Spectrometry (TIMS), combined with Fe(OH)₃ scavenging and anionic exchange chromatography. Less satisfactory, but much quicker, is direct retention of actinides from HNO₃ by means of TRU resin and MC-ICP-MS detection. We have tested these methods on gypsum speleothems from the Sorbas karst in Spain and from the Naica caves in Mexico.

DOI

http://dx.doi.org/10.5038/1827-806X.39.1.5

Recommended Citation

Sanna, Laura; Francisco Saez; Siri Simonsen; Silviu Constantin; José-Maria Calaforra; Paolo Forti; and Stein-Erik Lauritzen. 2010. Uranium-series dating of gypsum speleothems: methodology and examples. International Journal of Speleology, 39: 35-46.
Available at: https://digitalcommons.usf.edu/ijs/vol39/iss1/5