Just out | Palynological data from sediments of the Hunsruckschiefer type, Lower Devonian of the SW Hunsruck, Germany @ Bulletin of Geosciences

Just out @ Bulletin of Geosciences



Brocke R, Kneidl V, Wilde V, Riegel W


The Devonian Hunsruckschiefer is an outstanding Palaeozoic Fossillagerstatte, widely known for the exceptional preservation of a highly diverse fossil assemblage at the classical sites of Gemunden and Bundenbach. However, biostratigraphical marker fossils are rare and tectonic deformation in the Hunsruck is extremely complex. Therefore, the exact stratigraphic range of the Hunsruckschiefer Lagerstatte and its facies equivalents is still not well understood. Palynological evidence has thus far been very limited because of poor preservation and high thermal alteration. The sediments of the Hunsruckschiefer type (here Zerf Formation) from the newly described Siesbach section have now yielded a rather diverse and reasonably well preserved assemblage of spores and, for the first time, of marine phytoplankton and scolecodonts. Spore assemblages are composed of morphologically simple cryptospores and typical Lower Devonian trilete spores such as Retusotriletes, Apiculiretusispora, Emphanisporites and Streelispora. Phytoplankton assemblages include prasinophytes (Tasmanites, Dictyotidium, Cymatiosphaera, Lophosphaeridium) and various acritarchs (Veryhachium, Micrhystridium, Multiplicisphaeridium, Gorgonisphaeridium). An upper Pragian to lower Emsian (late Siegen) age is suggested for the studied section based on known stratigraphic ranges of the identified spore taxa. Thus, the Zerf Formation appears to be older than the Hunsruckschiefer Lagerstatte at Gemunden and Bundenbach, in which typical Emsian marker species have been observed. The environmental significance of the proportion of marine and terrestrial palynomorphs is briefly discussed.

READ IT HERE: http://www.geology.cz/bulletin/contents/art1614

Lurdes Fonseca

Assistant Professor and Researcher at University of Lisbon