Hydrogeochemistry and genesis of metasilicate spring water in the Changbai Mountain basalt area,NE

There have been many volcanic activities in the basalt area of Changbai Mountain, NE China is abundant in metasilicate spring water due to its unique geological conditions. This study analyzed the hydrochemical characteristics and genesis of the spring water based on analyses of water chemistry, water isotopes, SF6 and lithology of the volcanic rocks. Results show that the spring water is mainly recharged by local precipitation, with an elevation of 430.3-1033.5 m, then run along water conductive faults and discharges at low-lying areas as springs. The circulation depth of the groundwater is about 13–169 m, which is less than the thickness of the whole basalt layer, indicating that the groundwater circulation is limited to the basalt layer. The SF 6 age of the spring water is around 8.5-35.0 a, indicating a rather fast flow rate. The main hydrochemical facies of the spring water is HCO 3 –Ca·Mg·Na, followed by HCO 3 –Na·Mg·Ca and HCO 3 –Mg·Na·Ca.Based on cross-plots of main chemical components, Pearson Correlation and Principle Component Analysis (PCA), the origin of the solutes in the groundwater and the main water-rock interactions are identified.