Signal Formation in Geochemical Archives – The Role of Organic Matter and its Fate in Aquatic Systems

Extraction of geochemical signals of environmental or climatic changes are crucial for our understanding of past and for the prediction of future environmental change. In Earth Science, numerous proxies are used in different geochemical archives to reconstruct environmental or climatic conditions through time and space. Such proxies are often used in a manner of relative change without exactly knowing which processes control the signal formation within the ecosystem or how the signal is altered through time. In a living world, organic matter, specifically its origin and alteration plays a crucial role for the formation of many environmental proxies. The talk will present examples of signal formation of different proxies in different geochemical archives such as limnic or marine sediments and will critically discuss the influence of primary productivity and organic matter decomposition.