Comment on 'Maximilian Hansen, Denis Scholz, Bernd R. Schöne, Christoph Spötl, Simulating speleothem growth in the laboratory: Determination of the stable isotope fractionation (δ13C and δ18O) between H2O, DIC and CaCO3' Chemical Geology 509 (2019) 20–44
| Autor: | Wolfgang Dreybrodt |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Calcite
geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Kinetic model δ13C Stable isotope ratio δ18O Speleothem Thermodynamics Geology Fractionation 010502 geochemistry & geophysics 01 natural sciences chemistry.chemical_compound chemistry Geochemistry and Petrology Kinetic fractionation 0105 earth and related environmental sciences |
| Zdroj: | Chemical Geology. 533:119236 |
| ISSN: | 0009-2541 |
| DOI: | 10.1016/j.chemgeo.2019.07.011 |
| Popis: | In this comment it is shown that analysis of the fractionation constants of the DIC describing the enrichment of 13C and 18O along the flow path of a thin water layer flowing down an inclined marble plate precipitating calcite in analogy to precipitation to speleothems, enables one to decide whether the Rayleigh-Distillation-model or the kinetic model is valid. Appropriate analysis of etot values for carbon and oxygen as reported by Hansen et al. (2019) reveals the validity of the kinetic model and allows determining the constants ekin and λ. This is in contrast to findings of Hansen and coauthors and gives a deeper understanding of the meaning of kinetic fractionation during precipitation of calcite. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect