Bregenz: Vorarlberg Museum Elemental (C/N ratios) and isotopic (δ15Norg, δ13Corg) compositions of sedimentary organic matter from a high-altitude mountain lake (Meidsee, 2661 m a.s.l., Switzerland): Implications for Lateglacial and Holocene Alpine landscape evolution.
Collection EDYTEM, Cahiers de Paléoenvironnement: Vol.
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.
In alpha decay, the nucleus ejects a helium nucleus (alpha particle) composed of two neutrons and two protons, dropping the mass of the original nucleus by four mass units.
The purpose of this chapter is to explain the process of radioactive decay and its relationship to the concept of half-life.
Samples used for radiocarbon dating must be handled carefully to avoid contamination.
Not all material can be dated by this method; only samples containing organic matter can be tested: the date found will be the date of death of the plants or animals from which the sample originally came.
Wood contains cellulose, lignin, and other compounds; of these, cellulose is the least likely to have exchanged carbon with the sample's environment, so it is common to reduce a wood sample to just the cellulose component before testing.
However, this can reduce the volume of the sample down to 20% of the original size, so testing of the whole wood is often performed as well.