Hydrogeochemical Characteristics and Genesis Model of Jinjiang and Julong Hot Springs in Changbai Mountain, Northeast China

Changbai Mountain in China has been explored as a potential area for its rich hot springs including the Jinjiang and Julong hot spring groups. The hydrogeochemical characteristics and conceptual genesis models of the Jinjiang and Julong hot springs were evaluated by hydrogeochemical analysis, isotope analysis, rock sample analysis, hydrogeochemistry simulation, and geophysical exploration method. The results showed that HCO3− and Na+ were the most abundant anion and cation in the hot springs, and the hydrochemical type was Na-HCO3. And the hot springs are enriched with trace components such as H2SiO3 and Sr. The major gas composition of the Jinjiang hot springs and Julong hot springs were CO2, N2, and CH4, which were derived from the mantle. The chemical compositions were produced by feldspar and pyroxene mineral hydrolysis. The recharge source of the hot springs was atmospheric precipitation and was also influenced by evaporation, and the genetic models for the Jinjiang hot springs and Julong hot springs were as follows: the heat source of both was a magma body and heat was mainly migrated in the form of thermal conduction. The cap rocks were both composed of trachyte of Baitoushan formation, basalt of Junjianshan formation, and rhyolitic pyroclastic rocks of Changbai formation. The geothermal reservoir of both hot springs was a fracture zone with the lithology of volcanic breccia, sand, and gravel and volcanic breccia and marble, respectively.