Abteilung Physische Geographie


QUASAP: Kinds and rates of soil-forming processes reflected in Quaternary soils and palaeosols and their use as palaeoenvironmental archives

Focus Group Leaders
Daniela Sauer, University of Göttingen, daniela.sauer@geo.uni-goettingen.de
Sergey Sedov, UNAM Mexico City, sergey@geol-sun.igeolcu.unam.mx
Dennis Dahms, University of Northern Iowa, dennis.dahms@uni.edu
Markus Egli, University of Zurich, markus.egli@geo.uzh.ch
Fabio Scarciglia, University of Calabria, fabio.scarciglia@unical.it
Pauline Y.D. Da Costa, University of Lomé, Togo, dzycosta@yahoo.fr

Dust Kluane, small
Dust storm on Slims River delta, Kluane Lake (July 2009). Photo: Paul Sanborn.

Terrestrial sediment sequences of various origins (e.g., deposited by rivers, wind or slope processes) represent valuable archives of Quaternary regional environmental changes. In periods of vegetation cover and stable land surfaces, soils start forming on these sediments. Thus, successions of sediments may contain intercalated fossil soils (palaeosols), recording phases of relative land surface stability. In contrast, each slope sediment layer burying a soil indicates an event or episode of slope instability due to climatic forcing or tectonics.

Whereas e.g. marine sediments and ice cores provide detailed records of global climatic trends, the strengths of terrestrial sediment-palaeosol records are that (1) they have wide spatial distribution and thus enable the detection of regional spatial patterns in palaeo-environmental conditions, and (2) in addition to palaeoclimatic information sediment-palaeosol successions record also the responses of landscapes to palaeo-climatic shifts. For instance, burial of a soil by a slope deposit may indicate that a climatic shift has reached a threshold at which a change from stable to dynamic land surface is initiated.

However, the use of palaeosols as a record of periods of stable land surfaces and environmental shifts within these periods requires profound knowledge on directions and rates of soil forming processes in different climates. The focus group QUASAP is making such knowledge available for future palaeo-environmental reconstructions. The group aims at assessing rates of soil forming processes in different climates, obtained from soils and palaeosols in settings where climatic conditions and duration of soil development are known.

Over the last years, the IFG QUASAP organized a series of field workshops, providing much time for discussions at the sediment-soil sections that were examined together. Through these discussions, international scientific collaborations have been initiated, and will most likely also be initiated during the upcoming workshops in 2018 (Yukon Territories) and 2019 (Ghent, Belgium). Joint projects involving colleagues from high- and low-income countries will be particularly encouraged, as the greatest knowledge gaps have been identified in Africa. This situation can only be improved through international collaboration in the respective regions.