鲁北平原阳信地区地热田地热地质特征及地热流体化学特征OA

Yangxin area in Shandong province is located in Huimin depression on the tectonic unit.Its northern edge is Wudi depression and the eastern edge is Zhanhua depression.The area is mainly charac-terized by subsidence tectonic movement,thick sedimentary strata of Paleogene,Neogene and Quaternary have been formed,and favorable conditions for the formation of geothermal resources have been created.6 construction boreholes have been drilled in Yangxin area,and all revealled hot mineral water of Guantao formation.The water temperature is 48～53 ℃,which belongs to warm water type geothermal resource.As showed by geothermal fluid chemistry,geothermal fluid in Yangxin area is saline water.Hydrochemi-cal type is Cl-Na type.The concentration standards of metasilicic acid,strontium,and lithium in geo-thermal water can reach medical value.It can be used as therapeutic mineral water.Analysis of Na-K-Mg ions at various points shows that geothermal water belongs to partially equilibrium water,and dissolu-tion is still ongoing.Geothermal isotopes of 8 18 O and δ2 H are close to the atmospheric precipitation line.It is indicated that hot water in the area originates from atmospheric precipitation.The estimation results of SiO2 temperature scale for thermal storage temperature indicate that the temperature of quartz is 53.22～66.66 ℃,the average geothermal gradient is 3.50 ℃/100m,and the estimated depth of thermal cycle is 1146～1530 m.