1. Behaviour of Cr in runoff from two catchments underlain by felsic bedrock.
- Author
-
Andronikov, A. V., Novak, M., Kram, P., Sebek, O., Andronikova, I. E., Efremenko, N. A., Borodulina, G. S., Subetto, D. A., Stepanova, M., Antalova, E., Levichev, M. A., Zobkova, M. V., and Chesalina, G. L.
- Subjects
- *
RUNOFF , *CHROMIUM isotopes , *BEDROCK , *WEATHER control , *FELSIC rocks - Abstract
Chromium isotope and chemical compositions in runoff from two felsic rock catchments, the Lysina (LYS; Czech Republic) and the Neglinka (NEG; northwest Russia), were studied. Three types of water were identified: Na-Ca-SO4 type for the LYS, Mg-Ca-Cl-HCO3 type for the NEG downstream, and Mg-Ca-Cl to Mg-Ca-HCO3 type for the NEG upstream. The Cr (III) liberated during soil/bedrock weathering oxidized to Cr (VI), which was the main dissolved Cr species in both catchments. Variations in δ53Cr values for LYS runoff (–0.07‰ to +0.37‰) reflected a sole Cr source, seasonality of weathering and hydrologically controlled leaching/export processes. In the NEG catchment, back-reduction of Cr (VI) to Cr (III) during riverine transport resulted in a decrease in Cr concentrations (to 10–30%) and in an increase of δ53Cr values (+0.09 to +0.42‰ for the upstream to +0.72 to +1.73‰ for the downstream). Groundwater discharge could have influenced the chemical composition of the downstream NEG runoff to some extent. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF