CAJ | 학술논문

对桂林地区地下河水、岩溶大泉中的δ13CDIC、δ18O及Ca2+、Sr2+含量进行了测试分析.结果表明,地下河水的δ13CDIC 值范围为–15.99‰~–12.29‰,平均值为(–14.03±1.15)‰;δ18O 值范围为–6.63‰~–5.78‰,平均值为(–6.24±0.24)‰.岩溶大泉的δ13CDIC 值范围为–15.26‰~–9.22‰,平均值为(–12.05±1.57)‰;δ18O值范围为–6.97‰~–3.19‰,平均值为(–5.68±0.97)‰.岩溶大泉的δ13CDIC值、δ18O值比地下河水的分别偏重1.98‰和0.56‰.通过分析发现,水的循环方式引起了不同类型地下水的同位素差异,地下河以管道流的形式进行循环,循环速度快,水岩作用时间短,碳酸盐岩碳的贡献相对较少;同时,出口处水所经历的蒸发作用时间也短,水的δ18O值偏轻.岩溶大泉以裂隙流的形式进行循环,循环速度慢,水岩作用时间长,碳酸盐岩碳的贡献相对较多;泉口处水所经历的蒸发作用时间也长,水的δ18O值偏重.Sr/Ca值与δ13CDIC值具有正相关关系,而与δ18O值的相关性差.这意味着δ13CDIC值与 Sr/Ca值一样,可以在一定程度上反映出地下水的径流条件.
대계임지구지하하수、암용대천중적δ13CDIC、δ18O급Ca2+、Sr2+함량진행료측시분석.결과표명,지하하수적δ13CDIC 치범위위–15.99‰~–12.29‰,평균치위(–14.03±1.15)‰;δ18O 치범위위–6.63‰~–5.78‰,평균치위(–6.24±0.24)‰.암용대천적δ13CDIC 치범위위–15.26‰~–9.22‰,평균치위(–12.05±1.57)‰;δ18O치범위위–6.97‰~–3.19‰,평균치위(–5.68±0.97)‰.암용대천적δ13CDIC치、δ18O치비지하하수적분별편중1.98‰화0.56‰.통과분석발현,수적순배방식인기료불동류형지하수적동위소차이,지하하이관도류적형식진행순배,순배속도쾌,수암작용시간단,탄산염암탄적공헌상대교소;동시,출구처수소경력적증발작용시간야단,수적δ18O치편경.암용대천이렬극류적형식진행순배,순배속도만,수암작용시간장,탄산염암탄적공헌상대교다;천구처수소경력적증발작용시간야장,수적δ18O치편중.Sr/Ca치여δ13CDIC치구유정상관관계,이여δ18O치적상관성차.저의미착δ13CDIC치여 Sr/Ca치일양,가이재일정정도상반영출지하수적경류조건.
After sampling and analyzing carbon isotope (δ13CDIC) and oxygen isotope (δ18O) in subterranean river and large karst springs in Guilin, Guangxi Zhuang Autonomous Region, southwest China, we found:(a) the carbon isotopic (δ13CDIC) values in subterranean river ranged from–15.99‰to–12.29‰, with a mean value of (–14.03± 1.15)‰;and oxygen isotope (δ18O) values ranged from–6.63‰to–5.64‰, with a mean value of (–6.24±0.24)‰;the carbon isotopic (δ13CDIC) values in large karst springs ranged from–15.26‰to–9.22‰, with a mean value of (–12.05±1.57)‰; and oxygen isotope (δ18O) values ranged from –6.97‰ to –3.19‰, with a mean value of (–5.68±0.97)‰; (b) the carbon isotopic (δ13CDIC) and oxygen isotope (δ18O) values in subterranean river were generally lower than those in large karst springs; (c) the water circulation caused the isotopic differences in difference types of water. In subterranean river, water is in the form of conduit flow, with a fast rate of cycle and a short time of water-rock interaction. Therefore, little heavy carbon isotope (δ13CDIC) came from carbonatite rock to the water, with a short time of distillation process, so the carbon isotope (δ13CDIC) is light. In contrast, water in large karst springs is fissure flow, with a slow circulation rate and a long water-rock time, which lead more heavy carbon isotope came from carbonatite rock to the water, furthermore, its distillation process time is longer, so the carbon isotope (δ13CDIC) is heavy. δ13CDIC valued with the same situation as Sr/Ca, it could reflect the run-off condition of groundwater to some degree.