Stable chlorine isotope evidence for non-marine chloride in Badenian evaporites, Carpathian mountain region
✍ Scribed by C.J. Eastoe; T. Peryt
- Book ID
- 104463247
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 729 KB
- Volume
- 11
- Category
- Article
- ISSN
- 0954-4879
No coin nor oath required. For personal study only.
✦ Synopsis
Routine trace‐element geochemistry suggests that components in putative marine halite evaporites may be partly of nonmarine origin, but such interpretations are commonly ambiguous. Stable chlorine isotopes may provide a less‐ambiguous marker of chloride origin where δ^37^Cl departs from the range predicted for evaporite formation from seawater. Bedded halite with primary sedimentary textures preserves original δ^37^Cl values. Measurable change in δ^37^Cl can be generated by incongruent dissolution of halite, but only if less than half the original halite remains. Badenian (middle Miocene) halite from the Forecarpathian and from the East Slovakian and Transcarpathian basins has a δ^37^Cl range of – 0.2 to 0.8‰. Two phenomena cannot be explained by simple evaporation of 0.0‰ seawater. At Wieliczka, the Shaft Salt has distinctive δ^37^Cl values (– 0.2 to 0.0‰) relative to neighbouring salt beds (0.2 to 0.6‰), requiring a large, abrupt input of brine with negative δ^37^Cl. Halite with high (0.6 – 0.8‰) δ^37^Cl near the base of the East Slovakian and Transcarpathian evaporites requires a large input of chloride with positive δ^37^Cl into the basins. Expulsion of basin brine with non‐0‰δ^37^Cl into the evaporite basins may account for the nonmarine chloride sources.