Strontium stable isotopes fractionate in the soil environments?

This study shows that the stable isotopic composition of strontium (the Sr-88/Sr-86 ratio expressed as delta(88)/Sr-86 value relative to the NBS987 standard) varies significantly in sedimentary terrestrial environments. The abundances of Sr-86, Sr-88 isotopes were analyzed by MC-ICP-MS Nu Plasma. All studied rocks and waters show delta(88)/Sr-86 values that are distinctly different from the measured NBS987 standard (yielding 0.01 +/- 0.05%, all errors are reported as 2 sigma). Modern corals from the northern Gulf of Aqaba, Red Sea yielded significantly different value than seawater (delta(88)/Sr-86 = 0.22 +/- 0.07%, compared to 0.35 +/- 0.06%, respectively), in an excellent correlation with the 688116 SF analyses reported by Fietzke and Eisenhauer [Fietzke, J., Eisenhauer, A., 2006. Determination of temperature-dependent stable strontium isotopes (Sr-88/Sr-86) fractionation via bracketing standard MC-ICP-MS. Geochm. Geophys. Geosyst. 7 (no. 8)] on other coral samples. All carbonate samples that originated in the marine environment: corals (porites and acropora from the northern Gulf of Aqaba); Cretaceous limestone and runoff from the Judea Mountains as well as lacustrine evaporitic aragonite (Dead Sea); and Red Sea and Atlantic seawater yield an average delta(88)/Sr-86 value of 0.26 +/- 0.1%. On the other hand, secondary Materials (Products of chemical weathering) from the terrestrial environment of the Judea Mountain such as terra rossa soil and speleothem calcite (that derives its Sr from the above-lying soil) yielded significantly lower delta(88)/Sr-86 value of -0.17 +/- 0.06%.. This indicates that strontium isotopes fractionate in the soil environment calling for a possible development of strontium isotopes as a tracer for Processes of chemical weathering and pedogenesis. (C) 2008 Elsevier B.V. All rights reserved.