AMS radiocarbon and varve chronology from the annually laminated sediment record of Lake Meerfelder Maar, Germany

The Holocene varve chronology of annually laminated sediment sequences from Lake Meerfelder Maar agree for most of the record with dendro-calibrated a ccelerator mass spectronomy radiocarbon dates from the same site. Only betw een 9710 and 9950 cai BP does an offset of 240 yr appear between both data sets. At this position, a micro-disturbance in the varve succession has bee n detected by thin section analyses and was quantified in terms of missing varves. A comparison with the nearby record from Lake Holzmaar, as well pro viding high resolution AMS C-14 and varve chronologies, revealed that such gaps (ca. 2% in time for the entire Holocene) are exceptional for these lon g-varved maar lake records. Moreover. since sections of missing years appea r for both profiles at different stratigraphic positions, a combination of both the Meerfelder Maar and Holzmaar records enables us to bridge erroneou s zones in varve chronologies. This confirms the high potential of two long -varved records in close vicinity to each other for the elimination of dati ng errors rind for increasing chronological precision at a time resolution that is normally regarded as within the counting errors. Late Glacial varve and C-14 data beyond the dendro-calibration from Meerfelder Maar and their tentative tele-connections to other high resolution data sets reveal unexp lained age discrepancies in the calendar year time scale of about 200 years .