Subfossil forest in Zurich
The subfossil forest in Zurich is the archaeological find of a forest that is believed to be 14,000 years old, the remains of which are not or only partially petrified. He was in today's quarter Binz, of the district of Wiedikon in Zurich belongs.
location
The remains of the subfossil forest were discovered during excavation work at a depth of four to six meters. Some tribes have traces of falling rocks and fire. The trees were about 30 meters high when they were sedimented and "stood upright, with the roots down, as if they could come back at any time" . Presumably, it is the remains of a pine forest that was formed shortly after the last ice age under the most adverse environmental conditions. From the Uetliberg, which was freed from the glacier, mud trickled down the valley and gradually covered the forest. The trunks rotted away, but the roots and trunk stump were hermetically sealed in the layer of clay and have survived undamaged to this day.
Discovery and Exploration
Daniel Nievergelt, dendrochronologist the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), discovered by chance in passing on the edge of a muddy pit in the quarter Binz in April 2013, some of the construction workers to transport deposited stumps, including root system, which he described as remnants of pine trees identified . Felix Kaiser, a work colleague at the WLS, had previously made similar finds of subfossil remains of wood, for example in the Dättnauer Tal in Winterthur and around the Uetliberg in the Auenlehm der Reppisch and in 1999 during the construction of the Uetliberg tunnel . “These are the first proven trees that immigrated back to us from the Mediterranean area after the last Ice Age ... such finds are unique in the world,” commented Nievergelt. The researchers have now been able to secure around 200 strains. Except for the remains of probably a birch , all of them are pines. The trunks with laterally tapering, strong roots have a diameter of more than 30 centimeters and a few hundred tree rings .
With the support of construction management, the tree stumps were transported to the WSL site in Birmensdorf , Europe's largest laboratory for dendrochronology . Three wood samples from the several meters thick layer of clay were dated by the ETH Zurich using the radiocarbon method, which confirmed the WSL's assumptions: the wood was between 12,846 and 13,782 BP years . The previous finds in Zurich ranged from 12,700 BP to 14,100 BP.
According to the level of knowledge of the researchers involved, the quality and dimensions of the find are unique worldwide: They complement the global collection of environmental archives that contribute new knowledge about the climate after the last Ice Age, document changes in the landscape around Zurich and the genetic relationships between the pines found and their current ones Point out relatives. “The Strünke will cause a great stir in the international professional world and provide the data basis for numerous interdisciplinary research projects. There are already some similar old wood finds, but nowhere are they in such large quantities and in such good condition as in the Binz. "
For further evaluation, three tree slices are sawn out of each usable stalk and the wood and rings are analyzed. The first goal is to supplement the Central European annual ring tables , which contain annual rings that have so far been absolutely dated back to the year 12,594 BP. By comparing tree ring patterns, we look for overlaps that are necessary for absolute dating. With the finds from Zurich-Wiedikon, a gap in the previous chronology could be closed and the dating extended by around 2000 years. The data are of inestimable scientific value and are made accessible by WSL through the International Tree-Ring Data Bank (ITRDB).
The Federal Research Institute for Forests, Snow and Landscape (WSL) in Birmensdorf has succeeded in isolating the DNA of the subfossil pieces of wood. They belong to the species Pinus sylvestris . As a result, a forest of pine trees grew in the Binz after the last ice age.
Web links
Individual evidence
- ↑ a b c d e Tages-Anzeiger (May 21, 2013): Hélène Arnet: The oldest forest in the world , accessed on May 22, 2013
- ↑ a b c Archeology online: Subfossil forest discovered in Zurich ( Memento of the original from June 18, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , accessed May 25, 2013
- ↑ WSL December 18, 2017: DNA isolated from 13,000-year-old pines from Zurich's Binz
- ↑ Tages-Anzeiger of December 18, 2017: DNA from the Stone Age. Genetic studies of 14,000-year-old timbers from the Zurich Binz construction site enable a glimpse into the history of the earth
