RAD Analysis: Sediment Dating
Young sediments have an excess or “unsupported” concentration of Pb-210. Determinations of how the excess Pb-210 decreases with depth can be used to determine rates of deposition.
Maxxam measures the more sensitive Polonium-210 (Daughter of Lead-210) using alpha spectrometry.
Nuclear tests produced Cesium-137 that was deposited from the atmosphere. It is strongly absorbed on soil particles and has limited movement by chemical and biological processes. Most Cs-137 movement in the environment is by physical processes making Cs-137 an exceptional tracer for studying erosion and sedimentation.
* Dependent on the mass of the sample available.