Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Earth Sciences
Uranium-Series Dating Of Gypsum Speleothems: Methodology And Examples, Laura Sanna, Francisco Saez, Siri Simonsen, Silviu Constantin, José-Maria Calaforra, Paolo Forti, Stein-Erik Lauritzen
Uranium-Series Dating Of Gypsum Speleothems: Methodology And Examples, Laura Sanna, Francisco Saez, Siri Simonsen, Silviu Constantin, José-Maria Calaforra, Paolo Forti, Stein-Erik Lauritzen
International Journal of Speleology
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 …
Candoluminescence Of Cave Gypsum, John R. Sweet, John W. Hess, William B. White
Candoluminescence Of Cave Gypsum, John R. Sweet, John W. Hess, William B. White
International Journal of Speleology
A selection of gypsum specimens from a variety of caves as well as CaSO4 synthesized in the laboratory emit both a green and yellow candoluminescence when excited by a hydrogen diffusion flame. The green emission is attributed to dehydration of gypsum to bassanite and the yellow emission appears upon further dehydration to anhydrite. The source of the luminescence is ascribed to minor concentrations of Mn2+ in the gypsum.