• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.463-467
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• 2004

폐광산 지역내 사문암, 석회암 및 호온펠스와 지하수의 수질과의 상호관계를 비교 연구하였다. 암상별로 지하수를 채수하여 산화환원전위(Eh)와 수소이온농도(pH)를 측정하였다. Eh-pH 다이어그램을 작성한 결과 pH는 중성에서 약알칼리성으로 나타났으며, Eh는 -316.5～202.1 mV의 범위로 나타났다. 암상별 지하수의 파이퍼 다이어그램 분석 결과, 사문암 지/ 역에서는 $Mg^{2+}$-SO$_{4}$$^{2-}$ 형, 석회암 지역에서는 $Ca^{2+}$-HCO$_{3}$$^{-}$형이 우세하게 나타났다. 또한 호온펠스 지역에서는 $Na^{+}$＋K＋와 CO$_{3}$$^{2-}$ ＋HCO$_{3}$$^{-}$ 성분의 비가 다른 지역보다 높게 나타났다. 국부적인 폐광산 지역에서도 지하수내 주이온성분이 암상별 광물의 특징을 잘 반영하는 것으로 나타났다.

• Economic and Environmental Geology
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• v.50 no.6
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• pp.445-466
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• 2017

Yeongdong area is located in the contact zone between central southeastern Ogcheon belt and Yeongnam massif, in which Cretaceous Yeongdong basin exists. Therefore, the study area has complex geological environment of various geological age and rock types such as Precambrian metamorphic rocks, age-unknown Ogcheon Supergroup, Paleozoic/Mesozoic sedimentary rocks, Mesozoic igneous rocks and Quaternary alluvial deposits. This study focuses on the link between the various geology and water type, and discussed the source of some major ions and their related water-rock interaction. For this study, the field parameters and ion concentrations for twenty alluvial/weathered and eighty bedrock aquifer wells were used. Statistical analysis indicates that there was no significant differences in groundwater quality between wet and dry seasons. Although various types were observed due to complex geology, 80 to 84 % of samples showed $Ca-HCO_3$ water type. Some wells placed in alluvial/weathered aquifers of Precambrian metamorphic and Jurassic granitic terrains showed somewhat elevated $NO_3$ and Cl concentrations. $Mg-HCO_3$ typed waters prevailed in Cretaceous Yeongdong sedimentary rocks. The deeper wells placed in bedrock aquifers showed complicated water types varying from $Ca-HCO_3$ through $Ca-Cl/SO_4/NO_3$ to $Na-HCO_3$ and Na-Cl type. Groundwater samples with $Na-HCO_3$ or Na-Cl types are generally high in F concentrations, indicating more influences of water-rock interaction within mineralized/hydrothermal alteration zone by Cretaceous porphyry or granites. This study revealed that many deep-seated aquifer had been contaminated by $NO_3$, especially prominent in Jurassic granites area. Based on molar ratios of $HCO_3/Ca$, $HCO_3/Na$, Na/Si, it can be inferred that Ca and $HCO_3$ components of most groundwater in alluvial/weathered aquifer wells were definitely related with dissolution of calcite. On the other hand, Ca and $HCO_3$ in bedrock aquifer seem to be due to dissolution of feldspar besides calcite. However, these molar ratios require other mechanism except simple weathering process causing feldspar to be broken into kaolinite. The origin of $HCO_3$ of some groundwater occurring in Cretaceous Yeongdong sedimentary rock area seems to be from dissolution of dolomite($MgCO_3$) or strontianite($SrCO_3$) as well.