陕西安康月河盆地恒口地热井地热水化学及同位素分析

Geochemistry and Isotope analysis of thermal water from geothermal wells in Hengkou of Yuehe Basin,Ankang,Shaanxi province

通过对安康月河盆地地热地质条件、恒口地热井地热水化学分析成果及^(2)H、^(18)O和^(3)H、^(14)C同位素的研究,分析了恒口地热水的起源、地热水的变化及演化、同位素水文特征等。分析认为:恒口地热井地热水化学类型为重碳酸钠型(HCO_(3)^(-)Na),地热水中阳离子主要以Na^(+)、K^(+)为主,阴离子主要以HCO_(3)^(-)、CO_(3)^(2-)为主。地热水混入了一部分近代大气降水,是古水和现代水的混合型。根据放射性同位素^(3)H、^(14)C确定了地热水年龄为32520±1780a,根据氢氧稳定同位素计算了地热水主要补给高程为1423m往上,推断主要补给区为月河盆地南部的凤凰山及北部的牛山中-高山区。

Researches and study of geothermal water occurring in the Yuehe basin,thermal water chemistry and ^(2)H,^(18)O,and ^(3)H,and ^(14)C isotopes from the geothermal water wells in Hengkou area,original source,changes and evolution of geothermal water in Hengkou and isotopic hydrological characteristics indicated that the chemical type of geothermal water in Hengkou geothermal well is sodium bicarbonate type(HCO_(3)^(-)Na).The cations in geothermal water are mainly Na^(+)and K^(+),and the anions are mainly HCO_(3)^(-)and CO_(3)^(2-),mixing with a part of modern atmospheric precipitation and forming a mixture of ancient water and modern water.According to the radionuclide of ^(3)H and ^(14)C,the age of geothermal water is determined to be 32520±1780a.According to the hydrogen and oxygen stable isotope,the main recharge elevation of geothermal water is calculated to be 1,423m upward,it is inferred that the main supply areas are Fonghuangshan Mountain at the south of the Yuehe Basin and Niushan middle-high mountain area in the north.