14c dating soil
The preliminary results show that the C dates of both fractions become progressively older as the pyrolysis temperature is increased.In addition, the ages of the Py-V fractions are consistently younger than the corresponding Py-R fractions extracted at the same temperature. This involved soils archived in 1948, and recent samples, from a series of long-term sites in the North American Great Plains.
The percentage of nonhydrolyzable C and its TY - JOURT1 - Radiocarbon dating for determination of soil organic matter pool sizes and dynamics AU - Paul, E. The percentage of nonhydrolyzable C and its 14C age analytically identify the amount and turnover rate of the old resistant soil C.Humic acid (HA) was significantly older than humin, except for the mineral soil samples just beneath a forest floor (organic horizons), where the opposite was true.In peat sections, 14C ages of HA and humin were equally accurate.We conclude that in Andosols lacking a thick organic horizon, dating of HA renders the most accurate results, since humin was contaminated by roots.On the other hand, in mineral soil samples just beneath a forest floor, humin ages were more accurate because HA was then contaminated by younger HA illuviated from the organic horizons.
To determine which fraction should be used for 14C dating of Andosols and to evaluate if the chronostratigraphy of SOM is suitable for paleoecological research, we measured 14C ages of both fractions and related calibrated ages to soil depth for Andosols in northern Ecuador.