%A Olga E. KIKVADZE, Vasilii Yu. LAVRUSHIN, Boris G. POLYAK %T Chemical geothermometry: application to mud volcanic waters of the Caucasus region %0 Journal Article %D 2020 %J Front. Earth Sci. %J Frontiers of Earth Science %@ 2095-0195 %R 10.1007/s11707-019-0810-8 %P 738-757 %V 14 %N 4 %U {https://journal.hep.com.cn/fesci/EN/10.1007/s11707-019-0810-8 %8 2020-12-15 %X

The generation temperatures of gas-water fluids released from mud volcanoes in different provinces of the Caucasian region have been constrained using Mg/Li (ТMg/Li) chemical geothermometry. Mud volcanic fluids in the Taman Peninsula (Kerch-Taman mud volcanic province) were generated at temperatures (ТMg/Li) from 41 to 137°С. The depths of the respective mud reservoirs estimated from ТMg/Li values and local geothermal gradient are in a range of 1.0 to 3.4 km which spans the Maykop Formation of marine shale. For the South Caspian province, the ТMg/Li values of waters vary from 18 to 137°C and the respective root depths НMg/Li of mud volcanoes range from ~ 0.85 to 6.5 km. The obtained TMg/Li values for the analyzed mud volcanic waters from Caucasian provinces are in positive correlation with НСО3 contents and water oxygen isotope compositions (δ 18OH2O and Δδ 18OH2O) and in high negative correlation with Cl. The increase of ТMg/Li toward the Greater Caucasus Range, as well as the lateral TMg/Li patterns in the Taman and South Caspian mud volcanic provinces, support the idea that mud volcanic fluids generate at temperatures increasing progressively toward the Alpine orogenic belt.