摘要
为了研究河北平原地下水锶同位素的来源与形成机理,对所采水样进行了分析.研究了87Sr/86Sr比值"时间积累效应":随着地下水年龄和埋深的增大而增大;与地下水中过剩4Heexc呈正相关关系,与δ18O和δD呈负相关关系.探讨了Sr2+与87Sr/86Sr比值的关系,将地下水分为3类:(1)中等Sr2+含量与高87Sr/86Sr比值水(Ⅰ类水);(2)低Sr2+含量与高87Sr/86Sr比值水(Ⅱ类水);(3)高Sr2+含量与低87Sr/86Sr比值水(Ⅲ类水),即热水.通过综合分析认为:(1)河北平原第四系地下水中的放射成因Sr是由富含Na和Rb的硅酸盐矿物风化作用提供的,主要矿物为斜长石;(2)黄骅港热水中的放射成因Sr是由碳酸盐溶解形成的,87Sr/86Sr比值低,Sr/Na比值大;(3)补给区地下水是由流经火成岩和变质岩区地下水的侧向补给的,87Sr/86Sr比值中等.第三系地下水放射成因Sr的来源及形成机理尚须进一步研究.
To analyze the genesis of Sr isotopes in groundwater of Hebei plain, time-accumulative effect of ^87Sr/^86Sr ratios was studied. It is shown that ^87Sr/^86Sr ratio increases with the increasing age and depth of groundwater and has a positive correlation to ^4 Heexc and a negative correlation to δ^18O and δD. The groundwater is divided into three groups to discuss the relation between ^87Sr/^86 Sr ratio and Sr^2＋ content： （1） moderate Sr^2＋ content and higher ^87 Sr/^86 Sr （water Ⅰ） ; （2） lower Sr^2＋ content and higher ^87Sr/^86Sr （water Ⅱ） ; and （3） higher Sr^2＋ content and lower ^87Sr/^86Sr （water Ⅲ）, that is hot water. On the basis of integrated analysis, it was considered that （1） the radiogenic Sr in the Quaternary g roundwater（Q4-Q1 ） originates from weathering of silicate rich in Na and Rb, mainly from plagioclase; （2） the radiogenic Sr of hot water in Huanghua port is attributed to carbonate dissolution, with lower ^87Sr/^86 Sr and higher Sr/Na; （3） the recharge area is laterally recharged by the groundwater flowing through igneous and metamorphic rocks, with moderate ^87 Sr/^86 Sr ratio. However, the genesis of Sr isotopes in Tertiary groundwater needs further studies.
出处
《地球科学（中国地质大学学报）》
EI
CAS
CSCD
北大核心
2008年第1期137-144,共8页
Earth Science-Journal of China University of Geosciences
基金
中国地质调查局地质调查专题研究项目(No.2003201500002)
