北京延庆县松山温泉的特征与成因

松山温泉位于北京市延庆县松山森林公园内，附近为燕山期花岗岩，岩体裂隙较发育。在该温泉附近施工的2个钻孔自流热水。温泉及其附近自流孔热水水温为32~42 ℃，主要阳离子为Na⁺、K⁺和Ca²⁺，主要阴离子为SO₄^2-、HCO^-3和Cl^-，水化学类型为SO₄-Na型；热水矿化度为0.548~0.566 g/L，pH值为9.14~9.21，H₂SiO₃含量为87.1~97.1 mg/L，F^-含量为19.0~20.8 mg/L。氢、氧同位素资料表明，研究区地下热水来源于大气降水；估算的补给高程为1 256~1 351 m，补给区温度为4.4~8.8 ℃，热水年龄为14.19~48.95 a，地下热储温度为114~119 ℃，热水循环深度为2 236~2 274 m。松山温泉为花岗岩中地下水在山区获得大气降水入渗补给后，在经历深循环过程中获得深部热流加热后上升在山坡上出露形成的温泉。

Characteristics and Formation of the Songshan Hot Spring in Yanqing County of Beijing

The Songshan hot spring is located in the Songshan Forest Park in Yanqing County of Beijing. Gra nite occurs near the hot spring and fissures are developed in the rock. There are two wells flowing hot water closing to the hot spring. Temperatures of the hot spring and the flowing wells range from 32 ℃ to 42 ℃. The major cations of the hot water are Na⁺, K⁺ and Ca²⁺，and the major anions of the hot water are SO₄^2-, HCO^-3 and Cl-. The hot water is of SO₄-Na type. The hot water has TDS of 0.548-0.566 g/L, pH of 9.14-9.21, H2SiO3 of 87.1-97.1 mg/L and F- of 19.0-20.8 mg/L. Isotopic data of hydrogen and oxygen indicate that the hot water in the study area is of meteoric origin. The recharge altitude of the hot spring is estimated as 1,256-1,351 m, the temperature of the recharge area, 4.4-8.8 ℃, the age of the hot water, 14.19-48.95 a, the temperature of the geothermal reservoir, 114-119 ℃, and the circulation depth of the hot water, 2,236-2,274 m. The Songshan hot spring emerges on the mountain slope after the groundwater in the granite receives recharge from precipitation in the mountain area and undergoes deep circulation and obtains heat flow from beneath.