基于锶同位素的亚热带典型岩溶动力系统降雨条件下岩溶作用速率及其意义

发布时间：2018-02-04 09:55

本文关键词： 锶同位素岩溶作用速率降雨岩溶动力系统亚热带地区　出处：《地质论评》2017年01期 　论文类型：期刊论文

【摘要】：岩溶动力系统中微量元素及其同位素是指示岩溶动力系统运行过程及其环境意义的重要指标。本研究以我国南方亚热带地区典型岩溶动力系统为研究对象,利用高分辨率监测及采样方法研究了暴雨期昼夜尺度上岩溶泉水微量元素Sr及其同位素的变化特征,计算了暴雨条件下的岩溶作用速率。研究结果表明CO_2效应和稀释效应是降雨初期泉水水化学变化的主要控制机制,随后随着流量的持续上升,稀释效应占主导地位。降雨所导致的稀释效应对泉水Sr含量变化影响非常明显,但对岩溶泉水n(~(87)Sr)/n(~(86)Sr)同位素的影响非常有限。降雨期岩溶动力系统内持续的岩溶作用,维持了泉水相对稳定的n(~(87)Sr)/n(~(86)Sr)值特征。通过质量平衡方程计算表明暴雨期内补给的雨水溶蚀灰岩来源的n(~(87)Sr)/n(~(86)Sr)只占泉水总输出n(~(87)Sr)/n(~(86)Sr)的24.3%,当期补给的雨水所引发的CaCO_3净溶蚀速率为0.136 mg/(cm~2·d),其所产生的碳汇通量为1.01 t CO_2。这一结果初步确定了岩溶动力系统中"老水"和新近补给的雨水所导致的溶蚀速率差异和碳汇量差异,这为准确计算降雨诱发的岩溶溶蚀速率和碳汇量准确计算具有十分重要的意义。
[Abstract]:The trace elements and their isotopes in the karst dynamic system are important indicators to indicate the operation process and environmental significance of the karst dynamic system. This study takes the typical karst dynamic system in the subtropical region of southern China as the research object. The variation characteristics of trace element Sr and its isotopes in karst spring on the scale of day and night during rainstorm were studied by means of high-resolution monitoring and sampling method. The results show that CO_2 effect and dilution effect are the main controlling mechanisms of spring water chemical change at the beginning of rainfall, and then increase with the flow rate. Dilution effect is dominant. The effect of rainfall on Sr content of spring water is very obvious. However, the influence on the isotopic isotopes of the karst spring water is very limited. The karst process in the karst dynamic system during the rainfall period is very limited. The characteristics of the relative stability of the spring water are maintained. The calculation of mass balance equation shows that the source of the Rain Water dissolved limestone supplied during the torrential rain period is the source of the Rain Water limestone. Only 24.3% of the total output of the spring water is 87 ~ (87) ~ (?) ~ (?) ~ (?) ~ (?) ~ (?) ~ (?) ~ (?) ~ (?) ~ (?) ~ (?) ~ (?). The net dissolution rate of CaCO_3 caused by Rain Water recharge in the current period was 0.136 mg/(cm~2 路d). The carbon exchange amount produced is 1.01 t CO _ 2. This result preliminarily determines the difference of dissolution rate and carbon sink caused by "old water" and newly recharged Rain Water in karst dynamic system. This is of great significance for the accurate calculation of karst dissolution rate and carbon sink induced by rainfall.
【作者单位】：中国地质科学院岩溶地质研究所国土资源部广西岩溶动力学重点实验室;联合国教科文组织国际岩溶研究中心;
【基金】：国家自然科学基金资助项目(编号:41572234,41202185) 中国地质科学院基本科研业务费项目(编号:YYWF201636) 广西自然科学基金资助项目(编号:2016GXNSFCA380002,2012GXNSFBA053137) 国土资源部公益性行业科研专项经费项目(编号:201311148)的成果~~
【分类号】：P642.25
【正文快照】： 降雨条件下岩溶动力系统的水文、地球化学过替代矿物晶格中的Ca,Mg,并在碳酸盐岩溶解过程程分析始终是岩溶作用速率研究、岩溶作用与碳循中释放到地下水中(Clow et al.,1997)。在这一溶环研究中的重要方法。然而,一直以来所关心的一解一释放过程中,同位素《(87310/?(8631)

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