Based on delta Si-30 and delta Si-32 isotope geochemistry, the origin and e
volutionary mechanism of thermal springs in Jiaodong region are studied. Th
e mean value of delta Si-30 of dissolved silica of thermal spring water in
Jiaodong is 0.1 parts per thousand. Thermal spring water ages using delta S
i-32 dating method range from 387a. to 965a.