重庆芙蓉洞洞穴水DIC-δ^(13)C的变化特征及影响因素  

Variations of cave water DIC-δ^(13)C and its influencing factors in Furong cave,Chongqing

作　　者：黄春霞[1] 李廷勇[1,2,3] 韩立银[1] 李俊云[1] 袁娜[1] 王海波[1] 张涛涛[1] 赵鑫[1] 周菁俐 

机构地区：[1]西南大学地理科学学院,重庆400715 [2]中国地质科学院岩溶地质研究所/国土资源部广西壮族自治区岩溶动力学重点实验室,广西桂林541004 [3]国土资源部岩溶生态环境-重庆南川野外基地,重庆408435

出　　处：《中国岩溶》2016年第3期299-306,共8页Carsologica Sinica

基　　金：国家自然科学基金项目(41172165;41302138;41440020);中央高校基本科研业务费专项资金项目(XDJK2013A012;XDJK2014C010);岩溶动力学重点实验室开放基金资助课题(KDL201301);西南大学博士基金项目(SWU114022)

摘　　要：为了研究芙蓉洞滴水和池水中溶解无机碳碳同位素(DIC-δ^(13)C)的变化特征、影响因素及其气候环境指示意义,于2013年5月-2014年5月对芙蓉洞进行了洞穴监测。结果显示芙蓉洞山体土壤CO_2浓度和洞内空气CO_2浓度均表现出明显的季节变化特征,夏半年浓度偏高,冬半年浓度偏低,受温度和降水量的共同影响。芙蓉洞5个滴水点的DIC-δ^(13)C平均值为-8.98‰,两个池水点的DIC-δ^(13)C平均值为-6.98‰,池水的DIC-δ^(13)C比滴水的重2‰。对应2013年7月的干旱气候,洞穴水DIC-δ^(13)C在10月相应出现明显偏重值,偏轻的DIC-δ^(13)C值则是对湿润气候的滞后响应。洞穴水的DIC-δ^(13)C变化对地表气候的响应具有明显的滞后期。洞穴水DIC-δ^(13)C主要受土壤CO_2的影响,基岩溶解作用、包气带的开放性等因素也会对洞穴水DIC-δ^(13)C造成一定的影响。研究结果表明在短时间尺度上,洞穴水DIC-δ^(13)C变化响应了当地降水量以及地表湿润状况的变化。To explore the variation characteristics of DIC-δ^13C in the drip water and pool water in Furong ca- ve, Chongqing, their influencing factors, and their impact on climate, the cave had been monitored from May 2013 to May 2014. The results showed that the CO2 concentration for both the soil air and cave air was high in summer and low in winter, which displayed significantly seasonal variations. They were affected by the combined effects of temperature and precipitation. The average DIC-δ^13C value of the drip waters from five monitoring sites was --8.98%0, while the average DIC-δ^13C value of the pool waters from two monitoring sites was --6.98%0, showing that the DIC-δ^13C value of pool water was 2%0 heavier than that of the drip wa- ter. Corresponding to the arid climate in July 2013, the DIC-δ^13C of cave water became heavier in October, while the light DIC-δ^13C values indicated the delayed response to the humid climate. The DIC-δ^13C of cave water showed a significant lag period to respond the climate change. The DIC-δ^13C was dominantly affected by the soil CO2, also by bedrock dissolution, prior calcite precipitation and the opening degree of vadose zone. Our study demonstrates that on short time scales, the variations of DIC-δ^13C of the drip water in Fu- rong cave respond to the changes of local precipitation and the humidity conditions overlying the cave. Key words DIC-δ^13 C of cave water, soil CO2, concentration, water chemical characteristics, temperature and precipitation, Furong cave.

关 键 词：洞穴水DIC-δ^13C 土壤CO_2浓度 水化学特征 温度和降水 芙蓉洞 

分 类 号：P641.3[天文地球—地质矿产勘探]