济南四大泉群水化学特征及其成因分析

Hydrochemical Characteristics and Genetic Analysis of the Four Spring Groups in Jinan

为明晰济南四大泉群水化学动态变化特征及成因,利用离子比例系数、PHREEQC模拟以及氢氧同位素反演等方法分析各泉群水化学成分特征及其形成过程。研究表明:(1)四大泉群阳离子Ca^(2+)为优势离子,阴离子HCO_(3)^(-)为优势离子;(2)潭西泉和珍珠泉水化学类型稳定,而趵突泉和黑虎泉由HCO_(3)-Ca型变为HCO_(3)·SO_(4)-Ca型;(3)四大泉群受地表水、寒武系凤山组-奥陶系岩溶水以及寒武系张夏组岩溶水混合补给,其中趵突泉、黑虎泉接受寒武系凤山组-奥陶系岩溶水补给占比略大,而潭西泉、珍珠泉接受寒武系张夏组岩溶水补给占比略大;黑虎泉滞留时间最短,循环交替强烈;(4)水岩相互作用强弱程度导致泉群水化学成分差异,溶解沉淀作用强度整体大于阳离子交换作用。趵突泉阳离子交换作用强度最弱,黑虎泉伴随有去白云化作用,潭西泉和珍珠泉水化学作用及强度类似,进一步印证潭西泉和珍珠泉有相同的补给来源及运移机制。该研究成果对水资源合理利用和岩溶大泉的保护具有重要意义。

In order to illuminate the characteristics and causes of the hydrochemical dynamic changes of the four springs in Jinan,this work used the methods of ion proportion coefficient,PHREEQC simulation and hydrogen and oxygen isotope inversion to discuss the characteristics of the hydrochemical composition and formation process of the four springs.The results show that:(1)the four spring groups contain dominant cation Ca^(2+)and anion HCO_(3)^(-).(2)The hydrochemical types of Tanxi Spring and Zhenzhu Spring are stable,while Baotu Spring and Heihu Spring have evolved from HCO_(3)·SO_(4)-Ca type to HCO_(3)·SO_(4)-Ca type.(3)The four spring groups were supplied by surface water,karst water of the Cambrian Fengshan Formation-Ordovician and karst water of the Cambrian Zhangxia Formation.Among them,Baotu Spring and Heihu Spring were mainly recharged by karst water of Cambrian Fengshan Formation-Ordovician,while Tanxi Spring and Zhenzhu Spring were mainly recharged by karst water of Cambrian Zhangxia Formation.And the retention time of Heihu Spring is the shortest and the circulation alternation is the strongest.(4)The degree of water-rock interaction leads to the difference of water chemical composition in spring groups,and the strength of dissolution and precipitation is stronger than cation exchange.The Baotu Spring has the weakest cation exchange strength,and the Heihu Spring is accompanied by dolomitization.The hydrochemical action and intensity of Tanxi Spring and Zhenzhu Spring are basically similar,which further proves that Tanxi Spring and Zhenzhu Spring have the same supply source and migration mechanism.The research results are of great significance to the rational utilization of water resources and the protection of karst springs.