Origin and Evolution of Saline Spring Water in North and Central Laos Based on Hydrochemistry and Stable Isotopes (δD, δ18O, δ11B, and δ37Cl)

Xiwei Qin; Haizhou Ma; Xiying Zhang; Xiasong Hu; Guorong Li; Ziwen Jiang; Huaide Cheng; Jibin Han; Yongshou Li; Weiliang Miao; Wenhua Han; Sha Yang; Qian Song; Shang Lei; Hongying Wang

doi:10.3390/w13243568

Water (Dec 2021)

Origin and Evolution of Saline Spring Water in North and Central Laos Based on Hydrochemistry and Stable Isotopes (δD, δ18O, δ11B, and δ37Cl)

Xiwei Qin,
Haizhou Ma,
Xiying Zhang,
Xiasong Hu,
Guorong Li,
Ziwen Jiang,
Huaide Cheng,
Jibin Han,
Yongshou Li,
Weiliang Miao,
Wenhua Han,
Sha Yang,
Qian Song,
Shang Lei,
Hongying Wang

Affiliations

Xiwei Qin: Department of Geological Engineering, Qinghai University, Xining 810016, China
Haizhou Ma: Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Xining 810008, China
Xiying Zhang: Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Xining 810008, China
Xiasong Hu: Department of Geological Engineering, Qinghai University, Xining 810016, China
Guorong Li: Department of Geological Engineering, Qinghai University, Xining 810016, China
Ziwen Jiang: Department of Geological Engineering, Qinghai University, Xining 810016, China
Huaide Cheng: Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Xining 810008, China
Jibin Han: Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Xining 810008, China
Yongshou Li: Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Xining 810008, China
Weiliang Miao: Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Xining 810008, China
Wenhua Han: Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Xining 810008, China
Sha Yang: Department of Geological Engineering, Qinghai University, Xining 810016, China
Qian Song: Department of Geological Engineering, Qinghai University, Xining 810016, China
Shang Lei: Department of Geological Engineering, Qinghai University, Xining 810016, China
Hongying Wang: Department of Geological Engineering, Qinghai University, Xining 810016, China

DOI: https://doi.org/10.3390/w13243568
Journal volume & issue: Vol. 13, no. 24
p. 3568

Abstract

Read online

This paper discusses the origin and evolution of saline springs in north and central Laos, based on chemical and stable isotopes (δD, δ18O, δ11B, and δ37Cl). All the saline springs in this study are of the Na–Cl geochemical type. The geochemical and water isotope values suggest that the saline springs in this study are mainly derived from meteoric water and/or ice and snow melt from the surrounding mountains and that they also experienced strong evaporation and intense rock–water interactions. The ionic ratios, characteristic coefficients, ternary Ca–SO4–HCO3 phase diagrams, and saturation indices of minerals show that the dissolution of halite, sulfate, and carbonate rocks may be the solute sources for saline springs in this study, whereas the underground brines in the Thakhek potash mining area are geochemically influenced by the dissolution of carnallite and sylvite. The global geothermal δ11B–Cl/B relationship and δ11B values (5.50 to 36.01‰) of saline springs suggest a continental origin of B. This B is most likely derived from marine carbonate rocks and marine evaporates (gypsum and halite) of the late Cretaceous, which is similar to the saline springs of the Nangqen–Qamdo–Simao Salt Basin. The δ37Cl value (−0.12 to +0.79) and the Cl/Br ratio (4076 to 9853) show that dissolution of late cretaceous marine halite layers, atmospheric precipitation, and water–rock interactions between volcanic rocks, mudstones, and sandstone can restrict the δ37Cl values in saline springs. Results from silica geothermometry and multi–mineral equilibrium diagrams indicate that the reservoir temperatures for the saline springs range from 87–137 °C and experience deep circulation. Hydrochemical characteristic coefficients suggest that saline springs in the Muang Say basin may have leached sylvinite and carnallite and that the potash exploration prospect in this area is relatively good.

Published in Water

ISSN: 2073-4441 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Hydraulic engineering; Technology: Environmental technology. Sanitary engineering: Water supply for domestic and industrial purposes
Website: http://www.mdpi.com/journal/water/

About the journal

Abstract

Keywords