Understanding fluid behavior through ion and isotope data from the Yitong Basin, Northeast China

Rongsheng Zhao, Xuanlong Shan, Jian Yi, Ye Liang, Chunlong Li, Cuiying Qiu
2018 Canadian journal of earth sciences (Print)  
To evaluate ion origins and fluid behavior, the chemical properties of 6 thermal water sampled from the Eocene reservoir in the Yitong Basin (YB), Northeast 7 China, were investigated. The thermal water samples are classified as Na-HCO 3 -type 8 water and were fully equilibrated, except for Sijixiangkang (SJXK) and Yitong (YT). 9 The cations originate mainly from water-rock interactions (e.g. albitization and 10 weathering of plagioclase), while the anions originate from magmatic volatiles and
more » ... atic volatiles and 11 leaching of limestone and granite, which were heated by hot magmatic volatiles and 12 exhibited an evaporation-like pattern in the Gibbs's diagrams. The existence of 13 magmatic volatiles was verified by the high ion ratio, the minor element origins, δ 13 C 14 values of HCO 3 , and δ 34 S of SO 4 values, which flowed upward along lithospheric 15 faults, with higher fluxes in the northeast than in the southwest (the δ 13 C value of the 16 Chaluhe depression (CD) is 0.93‰ lower than that of the Moliqing depression (MD 17 1.63‰,)). Furthermore, according to the Br/Cl and HCO 3 -/Cl ratios and the δ 13 C 18 values, we speculate that a deep Permian limestone reservoir exists below the granitic 19 unit. Based on the ion origins and fluid potentials, we conclude that the CD and MD 20 are open systems rather than closed systems. The recharged water migrates from the 21 margin to the center in the plane, and in the vertical direction, it migrates from the 22 Page 2 of 50 https://mc06.manuscriptcentral.com/cjes-pubs Canadian Journal of Earth Sciences Yongji (E 2 y) and Sheling (E 2 sh) strata to the overlying strata and underlying 23 Shuangyang (E 2 s) strata along faults. By summarizing all of the available data, we 24 proposed a conceptual model of fluid migration. 25
doi:10.1139/cjes-2017-0154 fatcat:ixwqjrkmzrfvpauv7j66unz4u4