Mondsee progress November 2007
Mondsee was the first of the new sites we attacked within DecLakes. Field work started in June 2005, even before all partners had access to their respective funding. Nevertheless, the field campaign was a big success and certainly a great experience for all participants. Our strategy was to bring as many project members as possible, but at least one person from each working group, to the field sites. We wanted to have the "direct field observation" in any of the labs. In order to keep those up to 15 persons busy, cores produced by the coring team (five persons) were immediately opened, documented (macroscopic description, highly resolved photos, and spectrocolorimetry), subsampled for ostracodes, radiocarbon, thin slices, and magnetic properties by the corelab team (seven persons). The rest of the team was documenting and running the non-scientific logistics.
We got a 15-m-long composite profile built from seven 2-m-long sections from a first hole (MO05-1) and six sections from a secong hole (MO05-2, taken at about five m horizontal distance and overlapping roughly 1 m with two sections of MO05-1). The sediment-water interface was recovered with a small gravity core of 60 cm length which could be matched to the top section of MO05-1. The entire sequence is laminated, allowing to built up an absolute varve-chronology for the entire Holocene and probably a floating chronology for parts of the Late Glacial. During the Younger Dryas and the youngest part of the Alleröd, lamination is probably not good enough for varve-counting.
First radiocarbon data from terrestrial macrofossils are consistent with the varve-chronology as far as the latter is established.
Ostracode taxonomy and morphometry on samples from the Mondsee sediment core are almost finished, parts of the results have been presented at the annual meeting of the European Geophysical Union 2006 and the international meeting of IRGO (Frankfurt, 2007). Isotope analyses are finished for a low-res record cozering the entire sequence, in continuous 0.5-cm-steps for the last 2000 years, and are in progress for the mid-Holocene and Late-Glacial hi-res sections.
