Dating of Lake and Loess Sediments

Abstract

Lake and loess sediments represent archives that record important information about the local, regional and global climate conditions in the past. Lake sediments consist of autochthonous particles formed by biogeochemical processes within the lake and allochthonous particles brought into the lake from the catchment area. After deposition, the stratigraphy of the sediment can be altered by chemical, physical and biological processes. Under favored conditions, the sediment shows individual annual layers (varves), which can be used to date the sediment. Other dating methods are based on radioactive decay (14C, 210Pb) or on time markers such as tephra layers, deposits of natural catastrophes, e.g., floods, or radioactivity, e.g., emissions from a nuclear power plant.