Brachiopod faunas, facies and biostratigraphy of the Pridolian to lower Eifelian succession in the Rhenish Massif (Rheinisches Schiefergebirge, Germany)

2016 ◽  
Vol 423 (1) ◽  
pp. 45-122 ◽  
Author(s):  
Ulrich Jansen
Keyword(s):  
Rheinisches Schiefergebirge ◽  
Rhenish Massif

scholarly journals Field Trip A (23 September 2018): geology and geomorphology of Giessen and its surrounding areas

2018 ◽  
Vol 1 ◽  
pp. 3-13
Author(s):  
Frank Volker ◽  
Stefanie Menges
Keyword(s):  
Volcanic Rocks ◽  
Volcanic Field ◽  
Field Trip ◽  
Tectonic Activity ◽  
Rheinisches Schiefergebirge ◽  
Variscan Orogeny ◽  
Upper Rhine Graben ◽  
Rhenish Massif ◽  
Surrounding Areas ◽  
North And South

Abstract. This field trip is intended to present an introduction to the geological and geomorphological evolution of Giessen and its surrounding areas (Fig. 1). The conference location of Giessen is located at the intersection of three major geological and morphological units: the Rheinisches Schiefergebirge (Rhenish Massif) to the west, the Hessische Senke (Hessian Depression) to the north and south and the Vogelsberg volcanic field to the east (Fig. 2). The rocks of the Rheinisches Schiefergebirge (Rhenish Massif) were formed during Paleozoic times, in the context of the Variscan orogeny. Dominant rock types include graywacke, slate, quartzite, and limestone, as well as mafic and felsic volcanics and their related pyroclastics. The area north and south of Giessen is dominated by the Hessische Senke (Hessian Depression), a north–south-trending subsidence area with several individual deposit segments. Due to Cenozoic tectonic activity, the Hessian Depression can be regarded as a connecting segment between the prominent Upper Rhine Graben and the smaller graben structures of northern Germany, and this is also documented by less consolidated Tertiary and Quaternary sediments. Long-lasting subsidence of the Hessian Depression, however, is indicated by the presence of Permian and Mesozoic sedimentary rocks. Rotliegend rocks are present towards the southwest rim of the Vogelsberg volcanic field and the Hanau-Seligenstädter Senke. Minor occurrences of Zechstein rocks are exposed along the Lahn valley between Giessen and Marburg. Mesozoic strata are dominated by Buntsandstein and are widespread in the Marburg area, with Muschelkalk and Keuper rocks being restricted to small erosional remnants in tectonic graben structures. The area to the east of Giessen is dominated by the Miocene Vogelsberg volcanic field, where an estimated area of 2500 km2 is covered by volcanic rocks of varying thickness, the Vogelsberg thus being the largest volcanic field of central Europe. The field trip provides an introduction to the geology, earth history and geomorphological characteristics of Giessen and its surrounding areas. We will therefore encounter rocks that formed in distinct geodynamic environments and within a timespan of roughly 400 Ma (Devonian to present).

Coral-crinoid biocoenosis and resulting trace fossils from the Middle Devonian of the Eifel Synclines (Rhenish Massif, Germany)

2012 ◽  
Vol 86 (2) ◽  
pp. 282-301 ◽  
Author(s):  
Jan Bohatý ◽  
William I. Ausich ◽  
Elise Nardin ◽  
Christian Nyhuis ◽  
Stefan Schröder
Keyword(s):  
Middle Devonian ◽  
Biotic Interactions ◽  
Trace Fossils ◽  
Rich Source ◽  
Rhenish Massif ◽  
Rugose Corals ◽  
Source Of Information

Fossil echinoderms are a rich source of information concerning biotic interactions. In this study we analyzed the premortem encrustation of the highly specialized Middle Devonian rugose coralsAspasmophyllum crinophilumand ?“Adradosia” sp. on camerate crinoid stems.Aspasmophylluminfested living crinoid stems by sclerenchymal outgrowth that formed a skeletal ring but ?“Adradosia” sp. encrusted the stems rapidly, without building a ring. These coral-crinoid biocoenoses indicate a settlement advantage for the rugose corals within densely populated communities of the lower Givetian. The corals could be interpreted as large epizoozoans that benefited as secondary tierers reaching relatively high tiering levels. It also suggests the ability for the affected crinoids to repel the coral by overgrowing the corallite with a local increased stereomic growth. Because the crinoid axial canals are not penetrated, the corals cannot be considered as predators or parasites of crinoids. Therefore, the described biocoenosis is interpreted as commensalism. The speciesA. crinophilumis redescribed, and a neotype is defined, because of the loss of the initial types. Two types of ichnofossils can be attributed to the premortem encrustation of both corals. They are described asOstiocavichnusn. ichnogen. and are attributed to the stereomic response of the infested hosts. These swellings are characterized as either elliptical (Ostiocavichnus ovalisn. ichnogen. n. ichnosp. due to the assumed reaction ofA. crinophilum) or subcircular concavities (O. rotundatusn. ichnogen. n. ichnosp. due to the reaction of ?“Adradosiasp.”).

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