Eifel maar - Palaeoclimate archive
Lakes Holzmaar (HZM) and Meerfelder Maar (MFM), located only a few km apart in the Eifel Mountains, Germany, contain long annually laminated sediment records. While in the MFM record varves have been preserved from about 2,000 to 14,500 years BP, the HZM record is almost continuously varved for the last 24,000 years. Research on these record was initiated more than 20 years ago by the former head of the department Professor J.F.W. Negendank. Special emphasize has been on establishing varve chronologies as independent time scales that have been combined with AMS 14 C dating on terrestrial macrofossils. A large number of projects further concentrated on the reconstruction of centennial to seasonal climate variability. In particular, varve micro-facies variations and changes in seasonal diatom blooms have been developed as proxies for changes in the seasonal sedimentation pattern triggered by climate change. In combination with traditional physical, geochemical and biological proxies and more advanced proxies as, for example, transfer functions and stable carbon isotopes on organic matter distinct changes in the seasonality of climate during periods of pronounced cold phases like the Younger Dryas, Preboreal and Boreal Oscillations, the 8.2 ka ‘event', and the Little Ice Age have been proven. Varve counts demonstrated the extreme rapidity of these changes that took place only within 5-20 years. In addition to climatic oscillations, also regional and local settlement phases are recorded that provide detailed information on human-climate interactions especially during the last 3,500 years.
The varved sediments from lake Holzmaar show evidence of decadal to century scale climate variability during the early Holocene.
Multi-proxy evidence of mid- to late Holocene climatic changes at Lake Holzmaar, West-Eifel (Germany )
Applying high resolution diatomological, geochemical and varve analyses in combination with isotope geochemistry on annually laminated sediments from Lake Holzmaar, Eifel Region (Germany) a reconstruction of the palaeolimnological history for Lake Holzmaar and its catchment was achieved for the time window of ca 6350-1500 cal.
The diatom-based varve micro-facies - a quantitative integral expression of natural climate oscillations and human influence