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6.1. RADIOMETRIC DATING OF WATER AND SEDIMENTS 187
6.1 Radiometric Dating of Water and Sediments
The Forschungsstelle is an independent research unit funded by the Heidelberger Akademie der Wissenschaften.
Funding began in the year 1958 and will run until the end of 2010.
Personnel :
Prof. Dr. Augusto Mangini
Dr. Bernd Kromer
Dr. Marcus Christl
Dr. Denis Scholz
René Eichstätter, Technician
Maleen Gillmann, Technician
Sebastian Welk, Technician
Karoline Thomas, Secretary
Additional funding from the DFG, BMBF and EU (CarboEurope-IP):
Scientists: Pablo Verdes, Marcus Christl, Denis Scholz, Andrea Schröder-Ritzrau, Sahra Talamo,
Michael Friedrich,
PhD-students: Frank Bernsdorff, Holger Braun, Nicolas Latuske, Jörg Lippold, Marga-rita Koroleva,
Ingmar Unkel,
Technicians: Helga Baus, Maleen Gillmann, Sabine Kühr, Eva Gier and 4 student assistants
Master-students: Kerstin Bohn, Daniel Schimpf, Boris Schulze, Nicole Vollweiler, Patrick Wenderoth
The task of the Forschungsstelle ”Radiometrie”of the Heidelberger Akademie der Wissenschaften is
the dating and interpretation of climate archives. The research unit consists of two groups, the 14 C
Lab (Bernd Kromer) and the Th/U-Lab (Augusto Mangini).
14 C Lab The focus of the 14 C Lab are highly precise 14 C-dating and the construction of a calibration
curve for radiocarbon that reaches far back into the last Glacial. Furthermore this Lab delivers 14 Cdatings
for several archeological groups.
Methods We use both the conventional gas-counting technique and AMS. The gas counters were
developed to highest precision (better than 2 �). For AMS we prepare graphite targets, to be
measured at one of the European AMS facilities.
Extension of tree-ring based 14 C calibration into the Late Glacial In collaboration with
the tree-ring laboratories of the University Stuttgart-Hohenheim and the University of Zürich/WSL
Birmensdorf we extend the tree-ring based 14 C calibration into the past. Presently, the absolutely
(annually) dated oak and pine chronology starts at 12.400 years BP (before AD 1950) [Friedrich et
al., 2004; Reimer et al. 2004]. In the Late Glacial two independent chronologies were built in the two
tree-ring labs, assisted by numerous 14 C predating in our laboratory [Kromer et al., 2004; Schaub et
al., 2005]. Based on a comparison to the marine 14 C of [Hughen et al., 2004] the chronologies cover
the mid-Bølling, all of the Allerød and the initial 150 years of Younger Dryas (ca. 14,100 to 12,800
cal BP). The trees were recovered from gravel pits at the Danube river and its tributaries, the lignite
area south-east of Berlin, and construction sites in Zürich. Beyond the range of these chronologies we
assembled several floating 14 C sections from trees found in Northern Italy and Romania.
The 14 C data sets are evaluated to infer solar activity variability [Bond et al., 2001; Solanki et al.
2004, Usoskin et al., 2005] as well as ocean thermohaline circulation changes. Combined with 10 Be
time series from Greenland they may serve to link tree-ring and ice-core time-scales. From dendroclimatological
parameters of tree-rings, such as ring-widths, frost damage and growth patterns climate
anomalies can be reconstructed.
14 C dating, archaeology and geosciences We maintain extensive collaborations with archaeologists
to date key sites, such as Troy [Kromer et al. 2002] or the Nasca sites in Peru [Eitel et al.
2005], and to anchor floating tree-ring sections by 14 C wiggle-matching to the absolute scale. In the
’Roman Gap Project’ (http://www.arts.cornell.edu/dendro/2004News/ADP2004.html) we assist in
the extension of the Eastern Mediterranean chronologies into the first millennium AD, to link the
absolute part to the 2300-year long Bronze Age chronology [Manning et al., 2003]. The date of the
eruption of Thera remains a crucial and still controversial time marker of the Late Bronze Age in the
Eastern Mediterranean. In long-standing collaborations with colleagues in archaeology we contribute
to a high-precision 14 C date of this event [Manning et al., 2001].