Declining trend in the C 13/C 12 ratio of atmospheric carbon dioxide from tree rings of South African Widdringtonia cedarbergensis
This paper reports the first high-resolution (annual) C 13/C 12 chronology for both Africa and the Southern Hemisphere. The 77-yr stable carbon isotope chronology was developed from 6 Widdringtonia cedarbergensis trees from a site in the Cedarberg
Mountains, Western Cape Province, South Africa. The results indicate that C 13/C 12 ratios are not different from 1900 to 1949. After 1949, however, values become significantly more negative to 1977. This decline can be related to the anthropogenic impact
A magnetostratigraphic comparison between 14 C years and varve years during the Late Weichselian indicating significant differences between the time-scales
Datation ; Datation C 14 ; Géographie de l'Europe ; Paléomagnétisme ; Stratigraphie ; Suède ; Technique de recherche ; Varve
Statistical correlations between the two independantly dated time-scales suggest that at 10 500-10 200 14 C years B. P. the varvechronology exceeds the 14 C chronology by the order of 500-600 varve/year. Further correlations between the time-scales
at 12 000 14 C years B. P. suggest that the difference between the chronologies increased steadily from 12 000 to 10 000 14 C years B. P. If these correlations are correct they imply that the 14 C production rate increased steadily during the Late