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Evaporation Stage of Paleo‐saline Lake in the Sichuan Basin, China: Insight from Fluid inclusions in Halite
Author(s) -
DING Ting,
LIU Chenglin,
GUO Fusheng,
ZHAO Yanjun,
WANG Mingquan,
CHEN Liuqin
Publication year - 2020
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.14398
Subject(s) - halite , evaporite , geology , fluid inclusions , geochemistry , isotopes of oxygen , seawater , brine , structural basin , potash , mineralogy , potassium , quartz , oceanography , paleontology , chemistry , sedimentary rock , organic chemistry
Sichuan Basin is one of the most important marine–salt forming basins in China. The Simian and Triassic have a large number of evaporites. The Triassic strata have found a large amount of polyhalite and potassium‐rich brine. However, no soluble potassium salt deposit were found. In this study, the halite in well Changping 3 which is located at the eastern part of the Sichuan basin was studied using the characteristics, hydrogen and oxygen isotopes of the fluid inclusion in halite to reconstruct the paleoenvironment. The salt rocks in well Changping 3 can be divided into two types: grey salt rock and orange salt rock. The result shows that the isotopic composition of the halite fluid inclusion is distinct from the global precipitation line reflecting that the salt formation process is under strong evaporation conditions and the climate is extremely dry. At the same time, compared with the hydrogen and oxygen isotopes of brine in the Sichuan Basin and the hydrous isotope composition of the inclusions in the salt inclusions of other areas in China, it is shown that the evaporation depth of the ancient seawater in the Sichuan Basin was high and reached the precipitation of potassium and magnesium stage.