Rare earth elements into the aqueous phase of mud volcanoes of the Kerch-Taman region

This article presents original data on the content and distribution of major and rare earth elements into the waters phases from 26 mud volcanoes within the Kerch-Taman region. According to the chemical composition of the studied mud volcanic waters are represented by Na-Cl and Na-HCO3-Cl types, and the Cl/Br, Na/Cl, and Y/Ho ratios specify three main genetic groups of volcanoes. It was found that the rare-earth element contents in the aqueous phase of mud volcanoes are low (fractions of μg/L) and are distinguished by negative cerium anomalies and positive europium and holmium anomalies. The highest REE concentrations are observed in mud volcanoes located within the oldest Cretaceous sediments in the area of fault influence. As the distance from the Mesozoic source ΣREE sharply decreases. It has found that the free CO2 content in the aqueous phase regulates the REE content in waters and the value of cerium and europium anomalies.