Browsing Radiocarbon, Volume 26 (1984) by Subjects
Now showing items 1-20 of 23
-
Bomb 14C in the Ocean Surface, 1966-1981Bomb 14C has been used as a tracer for COin ocean surface water to study CO2 exchange between atmosphere and ocean. Using ordinary cargo ships for sampling, we have been able to cover some parts of the Atlantic, Pacific, and Indian Oceans for certain periods. A total number of 520 samples from 89 locations were measured during the last 15 years. The data are presented both in tables and graphs. A maximum 14C concentration (Delta-14C) of ca 20% was observed in temperate northern latitudes, and a few per cent lower at southern latitudes. A seasonal trend in the 14C variation, with summer maximum and winter minimum, was observed both in downwelling and upwelling areas.
-
Selective Leaching of Shells for 14C DatingAlthough acid leaching of shell carbonates prior to 14C assay is usually desirable, under some circumstances it can worsen contamination by preferentially solving unaltered shell and thus increasing the proportion of secondary carbonate. The risk can be eliminated by monitoring the progress of leaching with the help of microscopy and x-ray diffraction.
