西安凹陷中南部地下热水补给的环境同位素证据  

Environmental Isotope Evidence of Geothermal Water Recharge in Xi'an Southern Sag

作　　者：张雪莲[1] 马致远[1] 徐国芳[1] 

机构地区：[1]长安大学环境科学与工程学院,陕西西安710054

出　　处：《同位素》2014年第3期129-139,共11页Journal of Isotopes

基　　金：国家自然基金(41172211);陕西省自然科学基础研究计划重点项目(2012JZ5001)

摘　　要：应用环境同位素方法对西安凹陷中南部深层和浅层地下热水补给进行研究,结果显示,西安凹陷中南部浅层地热水样点主要分布在大气降水线附近,个别点发生δ18 O漂移,表明其接受来自秦岭北麓现代降水和古降水的混合补给,深层地热水氚含量小于1TU,14 C测年平均在两万年以上,表明其接受秦岭北麓全新世前古降水补给;深、浅层地下热水接受补给的方向为西南方向,补给高程为839~1 746m;深层(热水埋深为1 000~4 000m)、浅层(热水埋深小于1 000m)地下热水接受补给时的年平均温度为0.69℃,补给环境为孔隙裂隙型地下热水系统。The supply of Xi＇an depression southern abdominal deep and shallow under- ground hot water was studied with environment isotope method, the results showed that Xi^an depression abdominal shallow geothermal water points were mainly distributed near the line of atmospheric precipitation, only two points had diverged, meaning that they were accepted from modern precipitation and ancient precipitationin the north of Qinling Mountains , while the deep geothermal water with the tritium content was less than 1 TU and the average value of ^14C dating was more than twenty thousand, meaning that it was accepted from ancient precipitation recharge before Holocene in the north of Qinling Mountains. The result showed that the deep and shallow underground hot water inflowed from the southwest direction. The range of the recharge height was 839 m-1 746 m. The annual average temperature was 0.69 ℃ when the deep and shallow underground hot water received recharge. The recharge environment was the pore and fracture type undergroundhot water system.

关 键 词：西安凹陷中南部 地下热水 环境同位素 补给 

分 类 号：TL99[核科学技术—核技术及应用]