Chen, Bei-Bei;
Li, Si-Liang;
Pogge von Strandmann, Philip AE;
Zhong, Jun;
Ma, Ting-Ting;
Sun, Jian;
He, Wen-Yan;
(2023)
Calcium isotopic geochemistry of geothermal systems in the tectonically active southeastern Tibetan Plateau.
Science of The Total Environment
, 867
, Article 161534. 10.1016/j.scitotenv.2023.161534.
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Abstract
The global Calcium (Ca) cycle is closely coupled to the carbon cycle, and Ca isotopes have potential in tracing it. Even though groundwater is one of the main reservoirs of Ca at the Earth's surface, few data are available for groundwater, and the behavior of Ca and its isotopes in geothermal systems remains unknown. Here we analysed the stable Ca and radiogenic Sr isotope compositions of thermal waters distributed along the Jinsha and Yalong river valleys in the southeastern Tibetan Plateau. The Ca isotopic composition of the thermal water ranges from 0.45 to 2.16 ‰ (δ44/40Ca values relative to SRM 915a). The thermal waters collected from carbonate aquifers have higher δ44/40Ca values than bedrocks, which was attributed to secondary carbonate precipitation accompanied by CO2 degassing. In contrast, δ44/40Ca values in thermal waters collected from clastic and igneous rocks are similar to bedrock. Despite some thermal waters undergoing secondary silicates formation and CaNa ion exchange, such processes maybe not play a significant role in governing the Ca isotopic composition of these thermal waters. This suggests that Ca isotopes can be used to trace secondary carbonate precipitation driven by CO2 degassing (e.g. travertine) in geothermal systems located in tectonically active areas.
| Type: | Article |
|---|---|
| Title: | Calcium isotopic geochemistry of geothermal systems in the tectonically active southeastern Tibetan Plateau |
| Location: | Netherlands |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.scitotenv.2023.161534 |
| Publisher version: | https://doi.org/10.1016/j.scitotenv.2023.161534 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Calcium cycling, Calcium isotopes, Geothermal system, Groundwater, Tibetan Plateau, Water-rock interaction |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Earth Sciences |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10163906 |
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