Prospects for Eocene potash deposition in the East Tethyan domain: New evidence from fluid inclusions and chlorine isotope of halite crystals in the Kuqa Basin, NW China

• DOI: 10.1016/j.oregeorev.2023.105313
• Publication Date: 2023-01-25T10:07:25Z
• Authors: Hui-Dong Yu; Hao Zou; Jiang-Han Wu; Leon Bagas; Da-Xing Gong; Hai-Feng Cheng; Chang-Cheng Huang; He Zhu
• Keywords: Halite; Potash; Paleogene; Brine

The level of the Tethys Sea increased several times during deposition Mesozoic to Cenozoic sediments in Kuqa Basin Tarim Block. basin contains Paleogene Neogene units containing evaporite-rich layers, which are favourable sources for economic concentration potash (K-rich salt). However, basin's geology is poorly understood, lacking knowledge source brine, paleo-water temperatures, and degree evaporation. As a result, exploration mineralisation has been limited. This study documents geochemistry, fluid inclusions, Cl-isotope Early Eocene halite crystals from Basin. results show that homogenisation temperatures primary inclusions range between 20° 57 °C, close temperature seawater Tethyan sea same period. average value ∼ 32 °C taken as salt-forming brine Eocene. generally high, with maximum consistent global Paleocene–Eocene thermal (PETM) climatic event, indicating experienced long-term sustained high short-term extremely temperatures. recorded other parts earth, such 59 Silurian Michigan USA 58 Quaternary Lop Nur region Mongolia. In addition, Br content samples 125 ppm, × 103/Cl 0.11 0.21, evaporation curve seawater, there marine environment deposition. δ37Cl −0.7 −0.14 ‰ showing salinity evolved higher concentration, especially later stage indicates potential presence deposits high.