... chert from the Nobitz gravel pit ...

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This site providing cherts and petrified wood is distinguished by two features: the impressive amount of fossiliferous chert and the large variety of plant fossils allowing identification. The pit lies beyond the Saxon border in Thuringia, just beside the airstrip of the regional airport Altenburg, and can be easily reached via B180 road. The gravel and sand is taken from the water-filled pit which is also frequented by fisherman. Now and then in the course of excavation, strata rich in coarser material are met, which produce considerable amounts of various cherts. Although the volume fraction of potentially fossil-bearing cherts is low and difficult to quantify, it is much higher than in any other gravel pit in the area that has been checked. These cherts are mostly laminated and of whitish, gray, or brown colours. Many of them are only slightly rounded. Occasionally one can find samples with structured faces (Sigillaria trunk surface, fern pinnules, Macrostachya etc.), and on very rare occasions also conspicuous red cherts containing pinnules with sporangia (Scolecopteris) and other plant parts.

The cherts had been transported already in Upper Eocene (Tertiary) by the "Altenburg river". Very probably they came from the Ruedigsdorf/Wolftitz Rotliegend tuffs. Judging from their abundance and moderately rounded edges they were not transported far. A detailed investigation has not yet been done but would be a rewarding subject for a student project, for example.

text & photographs: R.KRETZSCHMAR/Chemnitz, photographs: H.SAHM/Dresden, F.ALBRACHT/Waltershausen, R.ROESSLER/MfNChemnitz

 
 

Nobitz gravel pit

P256Ho, "Maggot stone"

P211Ho, top face of chert layer fragment with Lycophyte cortex

top face of chert layer fragment with Lycophyte cortex

P308Ho, Syringodendron sp. with tissue structure

P307Ho, chert with ?Stigmaria sp.

P300Ho, chert with calamite fragments

chert layer surface with calamite strobilus

chert layer surface with sphenophyll axis

P305Ho, chert with ?Anachoropteris - frond stalks

P084Ho, chert with ?Psaronius sp.

P315Ho, chert with worm - like structure

"Maggot stone"

P222Ho, chert with fern pinnules

P309Ho, chert with „zipper structure“

P223Ho, silicite with unidentified tissue

 

observations

Lycopsids from North-West Saxony
a "maggot stone" from Nobitz
aerial roots in chert
exhibitions on fossiliferous cherts

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