Boaz Lazar, HUJI, Israel
Moti Stein, GSI, Israel
Ludwic Halicz, GSI, Israel
Determining the mechanisms and degree of Sr isotope fractionation in continental rocks and soils using column leaching experiments
The rock and immature soil material will be packed into experimental columns. A multichannel peristaltic pump will continuously flow freshwater enriched with CO2 (pCO2 of ~50,000 ppm, the range of soil pCO2) through the system. This water will be prepared by bubbling the water container with cylinder air containing 5% CO2 gas. Fraction collector will be used to collect the water that exits the column enabling to follow changes in Sr (and other major constituents) and its isotopic composition. The experiment will be preprogrammed and computer controlled. The system will allow for on-line introduction of different leaching agents (e.g., acetic acid, diluted HCl, ammonium nitrate, etc.) via controlled valves. Water samples collected with the fraction collector will be stored cold until chemical and isotopic analyses. The column solids will be analyzed by XRD and for the chemical composition at the end of each experiment.