Analysis of Temporal Environmental Isotopic Variation in Ground Water of the Georgia Piedmont

摘要: Time-series analyses were made of environmental tritium (3H) concentrations, the stable oxygen isotopic (δ18O) and major-ion composition natural waters from southeastern Piedmont Province Georgia. The sampling network consisted four fractured rock production wells (utilized at variable rates), one regolith monitoring well, two streams, rainfall. Although rainfall was highly (−11.8‰≤δ18O ≤−l.l‰ 2.3 ≤ TU 125), only minor variation (δl8O generally 1.0‰ 3H 2 TU) observed during period (∼ 1 year) within ground water a given well site. coefficients for bedrock aquifers (δ18Ocv cv < 10%) similar to those shallow (δ18Ocv= 5.6% 3Hcv= 3.3%). Ground most extensively used nearly isotopically geochemically invariant throughout year. Other than 0.3–0.5‰δ18O depletion late spring early summer, there few temporal trends little suggest presence seasonal component recharge extracted aquifers. This is consistent with 3H-modeled mean residence time this which ∼ 20–40 years. becomes well-homogenized by infiltrates meters below table, ground-water pumping does alter these mixing processes.