泰安臭泉成因研究及其水土地球化学特征

Study on the Origin of Chouquan Spring in Tai'an City and Chemical Characteristics of Water and Soil

泰安市西南25km的大汶口盆地东北部,出露一处目前山东省境内已发现的唯一的天然含硫化氢泉,泉水呈浅翠绿色,因其具有强烈的臭鸡蛋味被当地称为臭泉。经勘探查明臭泉泉域边界受地层岩性、断裂构造、埋藏条件等诸因素控制,含水层为埋藏的古近纪官庄群大汶口组三段含膏泥质灰岩,岩石呈密集蜂窝状溶蚀,地下水接受含水层露头带第四系孔隙水的下渗补给,在向排泄区径流运动过程中逐渐具有承压性并溶解了岩石中大量石膏组分而形成SO_4-Ca型水,处于封闭还原环境下水中的硫酸根离子在有机质作用下发生脱硫酸作用还原为硫化氢并溶于水中,地下水于泉点处遇阻水断裂产生壅水现象使水位抬升溢出地表成泉,硫酸根离子是生成硫化氢的供体。根据氢氧同位素分析结果,推断含硫化氢水为大气降水入渗补给和第四系孔隙水下渗补给、地下水以40年前的"古水"占优;含硫化氢水氟离子含量高于其他类型水,含水层埋藏条件为处于相对封闭的环境,土壤硫高值区与机(民)井分布、灌溉范围吻合。

The only natural hydrogen sulfide-containing spring that has been discovered in Shandong province is located at the northeastern part of Dawenkou basin which is 25km southwest of Tai'an city.The spring water is light green and green.Because it has a strong smell of rotten eggs,it is called Chouquan spring.The boundary of Chouquan spring is controlled by stratum lithology,fault structure and burial conditions.The aquifer is gypsum mudstone limestone in the third section of Dawenkou formation of Paleogene Guzheng group.Rock is densely honeycomb-like dissolution.Groundwater receives the infiltration and recharge of Quaternary pore water from aquifer outcrop.It gradually becomes confined and dissolves a large number of gypsum components in the rock during runoff movement to the discharge area,thus SO4 Ca type water was formed.Under the action of organic matter,sulfate ions in water under the closed reduction environment will occur esulphurization,and hydrogen sulfide is reduced and dissolved in water.Backwater phenomenon occurs when groundwater meets water-blocking fracture at the spring point,which causes water level to rise and spill over to the surface to form springs.Sulfate ion is the donor of hydrogen sulfide.Based on the results of hydrogen and oxygen isotope analysis,the age of hydrogen sulfide-containing water and the condition of recharge and drainage have been analyzed.At the same time,the groundwater dynamics and geochemical characteristics of water and soil are revealed.