Twenty-five years of radiocarbon dating soils: paradigm of erring and learning

Abstract

Rejuvenation of soil carbon was felt to be the principal impediment to absolute soil dating, in addition to the ambiguity of the initiation point of soil formation and soil age. Recent studies, for example of Becker-Heidmann (1989), indicate that a soil 14C age of >1000 yr cannot have >0.1% rejuvenation in the total soil organic matter compartments/fractions to be possible and sustainable. Always problematic in earlier observations were age vs. depth increases, in 14C profile curves showing an inflection of reduced age in the deepest samples, ie from the rim of the organic matter containing epipedon. Optimization of soil dating is, to a lesser degree, related to the applied extracting solvent system than to soil texture reactions. Such observations allow us to mitigate error ranges inherent in dating dynamic soil systems. -from Authors