Accession Number : AD0690265

Title :   THE EVALUATION AND APPLICATION OF C14 DATING OF GROUND WATER.

Descriptive Note : Final rept. 1 Jan-31 Dec 66,

Corporate Author : GEOLOGICAL SURVEY WASHINGTON D C

Personal Author(s) : Hanshaw,Bruce B.

Report Date : JUL 1969

Pagination or Media Count : 68

Abstract : During the period covered by this proposal a method for the direct determination of ground-water ages and flow rates was developed based on the carbon-14 content of the dissolved carbonate species in the ground water system. Most of the C14 content of the dissolved carbonate species in ground water comes from the soil-zone CO2 and is derived principally from the oxidation of organic matter within this zone. Dissolved carbonate species within the ground water may come from the CO2 of the soil-zone and also from solution of limestone in the aquifer; in some cases magmatic, petroleum- or plant-derived CO2 may be introduced into the aquifer also. Soil-zone CO2 is derived from plant respiration and decay and its carbon isotope composition should be equivalent to that of plants. Marine limestone from the aquifer will contain no carbon-14 because of its age and will dilute the datable, soil-zone-derived carbon. To determine true age of ground water the measured carbon-14 content must be corrected for this solution of limestone and dilution of carbon-14. (Author)

Descriptors :   (*WATER, GEOLOGIC AGE DETERMINATION), RADIOACTIVE ISOTOPES, CARBON COMPOUNDS, SAMPLING, FLUID FLOW, WATER WELLS, LIMESTONE, HYDROLOGY, ACCURACY, FLORIDA

Subject Categories : Geology, Geochemistry and Mineralogy
      Hydrology, Limnology and Potamology

Distribution Statement : APPROVED FOR PUBLIC RELEASE