沂水县富锶地下水特征及成因分析

Characteristics and Origin Analysis of Strontium-rich Groundwater in Yishui County

沂水县富锶(Sr)地下水分布广泛,白垩纪沂南序列侵入岩的锶(Sr)含量最高,平均含量1013.64×10^-6,其次为白垩纪火山岩,锶(Sr)平均含量为739.18×10^-6,太古代侵入岩、变质岩中的锶(Sr)平均含量为398.99×10^-6,寒武-奥陶纪灰岩、页岩中的锶(Sr)平均含量为201.54×10^-6;碎屑岩类孔隙裂隙水含水岩组地下水锶(Sr)平均含量为0.99mg/L,喷出岩孔洞裂隙水含水岩组地下水锶(Sr)平均含量为0.95mg/L,碳酸盐岩裂隙岩溶水含水岩组地下水锶(Sr)平均含量为0.76mg/L,块状岩类(侵入岩)裂隙水含水岩组地下水锶(Sr)平均含量为0.48mg/L。碎屑岩类孔隙裂隙水含水岩组、喷出岩孔洞裂隙水含水岩组、块状岩类(侵入岩)裂隙水含水岩组地下水中锶(Sr)主要来源为围岩的风化溶解;碳酸盐岩裂隙岩溶水含水岩组地下水中锶(Sr)主要来源于沂南序列构造破碎带和风化带的风化溶解,其次为寒武-奥陶纪灰岩的风化溶解,锶(Sr)强变异性与不同含水层地下水的混合比例有关。

The strontium(Sr)-rich groundwater is widely distributed in Yishui county.The Cretaceous Yinan intrusions have the highest strontium(Sr)content.The average content is 1013.64×10^-6,and followed by Cretaceous volcanic rocks with an average strontium(Sr)content of 739.18×10^-6.The average content of strontium(Sr)in Archean intrusive rocks and metamorphic rocks is 398.99×10^-6,and the average content of Sr in Cambrian-Ordovician limestone and shale is 201.54×10^-6.The average strontium(Sr)content in the groundwater of the clastic pore-fractured water-bearing rock formation is 0.99 mg/L,and the average strontium(Sr)content in the groundwater of the pore-spouting water-bearing rock formation is 0.95 mg/L.The average content of strontium(Sr)in the groundwater of the carbonate fractured karst water aquifer group is 0.76 mg/L,and the average content of strontium(Sr)in the groundwater of the fractured water aquifer group of block rocks(intrusive rocks)is 0.48 mg/L.The main source of strontium(Sr)in the groundwater of clastic rocks is the weathering and dissolution of the surrounding rocks.The strontium(Sr)in the groundwater of the carbonate rock fissure karst water aquifer is mainly derived from the structural fracture zone and weathering zone of the Yi’nan rock suite,followed by Cambrian-Ordovician limestone.The strong strontium(Sr)variability is also related to the mixing ratio of groundwater in different aquifers.