A Study Of The Hot Springs In Chichen And Fengning Counties Of Hebei Province

Geothermal features has been concerned by domestic and foreign geologists. It isrenewable resource which comes from the Earth’s interior. It had been used long timeago, and has gradually been used for heating, greenhouse cultivation, agriculture and soon. Studies of hot spring’s outcropping characteristics, distribution characteristics,origins analysis, evolution, thermal storage temperature and other issues are of animportant guiding significance for the scientific, effective and sustainable developmentand utilization of hot spring resources.The study area is located Chengde City and Zhangjiakou City in the northwest ofHebei Province. The geographical coordinate is: longitude115°~118°, latitude40°40’~41°20’. There are eight hot springs: Yangshugou Spa (A26), Hongtangsi Spa (A9),Tangzimiao Springs’ north spring (A3), Akagi spa’ hot spring (A2), Stomach Spring(A2-2), Hiraizumi (A2-3), Bronchitis Spring (A2-4), Eye spring (A2-5). Stratum of thestudy area is from the old to the new: the Archean, Proterozoic, Paleozoic, Mesozoicand Cenozoic. Magmatic activity of obvious polycyclic was very strong and there are alot of intrusive rocks and many chasms.The hot springs: A26, A3, A2, A2-2, A2-3andA2-5are exploded in similar granite outcrops, Hydrocheical type are all SO4-Na; whileA9Hongtangsi Spring’s outcropping rock containing breccia and tuff, the springscontains a higher amount of HCO3-, Hydrocheical type is SO4HCO3-Na, and is deepcycling springs; A2-4’s forming environmental is different from other springs, thesprings is shallow cycling springs, the cycle time is short and the temperature is low,Hydrocheical type is SO4HCO3-Na Ca.The study area’s spas are the low temperature hot springs, the temperature rangesfrom28℃to53℃. pH is about8for alkaline water; TDS is less than1, and the hotwater is fresh water. Hydrocheically, Na+is dominant, in cation and SO42-in anion, andF and H2SiO3are high in the hot water. PHREEQC software was used to calculate theseven basic components of the spas, H+, OH-and SiO2and to get the equilibriumdistribution percentage of their respective water-soluble components. The mineralsaturation indices were calculated in the study area, showing that marble, calcite and chalcedony are in an equilibrium state, and the rest are in a non-saturated or saturatedstate.2H and18O is otopic characteristics of the study area indicate that the spring waterrecharge from precipitation, and taking use of the elevation and temperature effects of2H and18O. We can calculate the recharge area of the springs in study area is between1200m and1800m.226Ra and222Rn were used to calculate the hot waters’ages:15-33a.The temperatures of geothermal resevoir are between60℃and90℃and thecirculation of the hot water depth is about2000to2900m.