Publication Date:
2022-11-30
Description:
Fossile Faunen aus dem tiefsten Oberems (Emsquarzit)werden mit vielen
Neufunden beschrieben. In der Diskussion der Faunen-Wende zwischen Unter- und
Oberems erweist sich der Brachiopode Adolfia pruemiensis (Drevermann) als bedeutende
Leitform für das tiefe Oberems. Für die heute vorliegende räumliche Verteilung
der Biofazies werden einerseits paläogeographische Fakten, andererseits großräumige
tektonische Prozesse als Ursache angenommen. Der paläontologische Teil der Arbeit
umfasst Bemerkungen und Untersuchungen der Trilobita Digonus intermedius (Vietor),
Trimerus crassicauda (Sandberger), der Bivalvia Stappersella lodanensis (Frech), Leptodesma
(Peraptera) lodanensis (Frech), Myalina (Myalina) circularis (Frech), Myalina
(Myalina) peltata n. sp., Rhenanomya tumida (A. Fuchs) und der Brachiopoden-Art
Euryspirifer robustiformis Mittmeyer.
Description:
Abstract: Biostratigraphic fossil research in the Koblenz-area (Lower Devonian, lower
part of Upper Emsian, Emsquartzite) is summarized in this report. In this region belonging
to the Rhenish Massiv thick layers of quartzites were deposited in the beginning of
the Upper Emsian substage. Only few fossil horizons with rieh fauna proving normal
marine shallow water conditions could be investigated. It can be presumed, thaf the visible
distribution of fossil horizons depends on paleogeographic facts.
In the youngest Upper Emsian sand was deposited into the Mosel-trough, probably
delivered by the Siegen-swell. Numerous outcrops show dominating thick quartzitic
layers resulting on changing sedimentary conditions. Heavy storms eroding older Sediments,
washed out all faunal assemblages. Other faunal elements may have been suffocated
by sand masses when the storms were slacking. So it can be believed, that optimal
living conditions for the Emsquartzite-fauna were reduced only to few locations.
The second part of this report contains investigations and remarks about the trilobite
species Digonus iniermedius (Vietor) and Trimerus crassicauda(Sandberger 1849), the
Bivalvia species Stappersella lodanensis (Frech), Leptodesma (Peraptera) lodanensis
(Frech), Myalina (Myalina) circularis(Frech), Myalina (Myalina) peltata n. sp., Rhenanomya
tumida (A. Fuchs)and the brachiopod species Euryspirifer robustiformis Mittmeyer.
The brachiopod species Adolfia pruemiensis (Drevermann) must be added to
other valid index fossils of the lower part of the Upper Emsian substage.
Description:
research
Keywords:
ddc:562
;
Rheinisches Schiefergebirge
;
TK 5611
;
Unterdevon
;
Trilobiten
;
Crinoiden
;
Gastropoda
;
Bivalven
;
Brachiopoden
;
Biostratigraphie
Language:
German
Type:
doc-type:article
,
publishedVersion
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