... chert from Ruedigsdorf ...

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The porphyr quarries near Ruedigsdorf had been described as abandoned for quite some time when they were inspected for geological mapping by ROTHPLETZ in 1901. According to information obtained from the local historical society at Kohren-Sahlis, work at the quarries ended in 1822. There were several small quarries producing fine-grained tuff stones since medieval times. They were used, for example, for the town hall at Altenburg(1561) and for buildings at Leipzig(1568). Plant fossils had been recovered from the quarries by DUERR, CRUSIUS, COTTA and GUTBIER. Their descriptions indicate the presence of fossiliferous cherts. GUTBIER, for example, describes a chert sample with fern imprint collected by DUERR. In his monograph “Dyas”, GEINITZ judges the Ruedigsdorf chert as “… an uncommon and therefore likewise remarkable layer …”. COTTA’s collection contains several sampless of petrified wood and chert from Ruedigsdorf. One can guess that there are more items in the history of palaeobotany that lead back to the Ruedigsdorf chert.

Nowadays the area around the former quarries at the Lenkersberg is crossed by footpaths suitable for leisure walks. The very quarries are heavily overgrown. We have not been able to find chert layers in primary bedding. Edgy chert fragments are sparsely distributed along the brooklet called Maus. The samples shown here were taken from there. It can be assumed that they belonged to some stratum of the Ruedigsdorf tuff. It has to be found out to which one.

The typical cherts from Ruedigsdorf are laminated, coloured in combinations of black, brown, and red, mostly without preserved plant tissue. In rare cases, Syringodendron and Stigmaria cf. ficoides imprints are seen on the top faces of the chert. There is a much rarer type of chert with peculiar unexplained plate-like and tube-like structures whose explanation seems difficult.

 
 

Lenkersberg near Ruedigsdorf

silicites from Ruedigsdorf

P147Ho, chert with Syringodendron

P066Ho, chert with Syringodendron

Stigmaria cf. ficoides

enigmatic "tube stone"

 

observations

Lycopsids from North-West Saxony
Where are the cherts from?
exhibitions on fossilferous cherts

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