A Piecewise Model for In Situ Raman Measurement of the Chlorinity of Deep-Sea High-Temperature Hydrothermal Fluids. Issue 9 (September 2021)

• Record Type: Journal Article
• Authors: Ge, Meng; Li, Lianfu; Zhang, Xin; Luan, Zhendong; Du, Zengfeng; Xi, Shichuan; Yan, Jun
• Is Part Of: Applied spectroscopy. Volume 75:Issue 9(2021)
• Page Start: 1178
• Page End: 1188
• Publication Date: 2021-09
• Subjects: In situ -- hydrothermal fluids -- Raman spectroscopy -- chlorinity -- OH stretching band; Spectrum analysis -- Periodicals; 543.505
• DOI: 10.1177/0003702821999114
• Languages: English
• ISSNs: 0003-7028

Abstract

The chlorinity of deep-sea hydrothermal fluids, representing one of the crucial deep-sea hydrothermal indicators, indicates the degree of deep phase separation of hydrothermal fluids and water/rock reactions. However, accurately measuring the chlorinity of high-temperature hydrothermal fluids is still a significant challenge. In this paper, a piecewise chlorinity model to measure the chlorinity of high-temperature hydrothermal fluids was developed based on the OH stretching band of water, exhibiting an accuracy of 96.20%. The peak position, peak area ratio, and F value were selected to establish the chlorinity piecewise calibration model within the temperature ranges of 0–50 ℃, 50–200 ℃, and 200–300 ℃. Compared with that of the chlorinity calibration model built based on a single parameter, the accuracy of this piecewise model increased by approximately 4.83–12.33%. This chlorinity calibration model was applied to determine the concentrations of Cl for high-temperature hydrothermal fluids in the Okinawa Trough hydrothermal field. Graphical Abstract