Université de Fribourg

Barium isotope fractionation during experimental formation of the double carbonate BaMn[CO₃]₂ at ambient temperature

Böttcher, Michael E. ; Geprägs, Patrizia ; Neubert, Nadja ; Allmen, Katja von ; Pretet, Chloé ; Samankassou, Elias ; Nägler, Thomas F.

In: Isotopes in Environmental and Health Studies, 2012, p. -

In this study, we present the first experimental results for stable barium (Ba) isotope (¹³⁷Ba/¹³⁴Ba) fractionation during low-temperature formation of the anhydrous double carbonate BaMn[CO₃]₂. This investigation is part of an ongoing work on Ba fractionation in the natural barium cycle. Precipitation at a temperature of 21±1°C leads to an enrichment of the lighter Ba isotope...

Université de Fribourg

A new model for estimating subsurface ice content based on combined electrical and seismic data sets

Hauck, Christian ; Böttcher, Michael E. ; Maurer, H.

In: The Cryosphere, 2011, vol. 5, p. 453–468

Detailed knowledge of the material properties and internal structures of frozen ground is one of the prerequisites in many permafrost studies. In the absence of direct evidence, such as in-situ borehole measurements, geophysical methods are an increasingly interesting option for obtaining subsurface information on various spatial and temporal scales. The indirect nature of geophysical soundings...

Université de Fribourg

Barium isotope fractionation in the global barium cycle: First evidence from barium minerals and precipitation experiments

Allmen, Katja von ; Böttcher, Michael E. ; Samankassou, Elias ; Nägler, Thomas F.

In: Chemical Geology, 2010, vol. 277, no. 1-2, p. 70-77

In this study, we present first results from an ongoing investigation on the stable barium (Ba) isotope fractionation in the natural barium cycle. Stable Ba isotope signatures of international IAEA reference materials (synthetic barium sulfate, IAEA-SO-5, -6, and barium carbonate, IAEA-CO-9), natural Ba minerals and experimental Ba precipitates have been analyzed as a first approach to evaluate...