Mud Volcanic Fluids of the Kerch–Taman Region: Geochemical Reconstructions and Regional Trends. Communication 1: Geochemical Features and Genesis of Mud-Volcanic Waters
V. Yu. Lavrushin, A. S. Aydarkozhina, É. V. Sokol, G. A. Chelnokov, О. Л. Петров
Abstract
The chemical and isotopic characteristics (δ18O and δ2H) of water from 42 mud volcanoes of the Kerch–Taman region (Crimean–Caucasus district) were analyzed. The formation temperatures of mud volcanic waters were estimated using the Mg-Li hydrochemical geothermometer (t(Mg-Li) = 40–134°C). It was revealed that dehydration waters released during the smectite–to-illite transformation play significant role in the total fluid balance of the mud volcanic systems (up to 80% of the total fluid volume). These waters are characterized by low Cl ion contents, δ18O from +13 to +17‰, and δ2H from –25 to –20‰ relative to VPDB, and high concentrations of $${\text{HCO}}_{3}^{ - }$$ , B, Li, Ba and other trace elements. Correlations between the concentration of HCO3, B, δ18O, and t(Mg-Li) values were revealed.