Spatial variations of radiocarbon in the coastal aquifer of Israel; indicators of open and closed systems.

Abstract

The spatial variation in radiocarbon concentration was studied in the Coastal Aquifer of Israel. Lower concentrations were found in the western section of the aquifer (55-70 pMC) as compared to the eastern section (80-100 pMC). Since no correlation was found between the tritium and radiocarbon values, these variations could not simply be explained by a difference in ages, or by a difference in the degree of old calcite dissolution as similar delta (super 13) C values were found throughout the aquifer. The results are best explained when viewing the differences in (super 14) C values within the same coastal aquifer, where the eastern section of the aquifer is a more open system and the western section is a more closed system. In general, the age of the groundwater in the coastal aquifer was found to be less than 50 years old ( (super 14) C>55 and measurable tritium).