Palaeogeography and tectonic structure of allochthonous units in the German part of the Rhenohercynian Belt: revision and comment (original) (raw)
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Geological Journal, 2001
The tectono-sedimentary evolution of the Rotliegend deposits of the northernmost margin of NE German Basin (NEGB) has been analysed on the basis of detailed sedimentary logs of 300 m of core material together with the re-evaluation of 600 km of seismic lines. Three distinct phases were recognized. During the initial Phase I, basin geometry was largely controlled by normal faulting related to deep-seated ductile shearing leading to a strong asymmetric shape, with a steep fault-controlled eastern margin and a gently, dipping western margin. The results of forward modelling along a cross-section ®t the basin geometry in width and depth and reveal a footwall uplift of c. 1000 m. Adjacent to the steep faults, local sedimentation of Lithofacies Type I was con®ned to non-cohesive debris¯ow-dominated alluvial fans, whereas the gently dipping western margin was dominated by alluvial-cone sedimentation.
2013
aBhandlungen der geologischen BundesansTalT, Band 66 issn 0378-0864 isBn 978-3-85316-071-8 alle rechte für in-und ausland vorbehalten. Verlag: geologische Bundesanstalt, neulinggasse 38, a 1030 Wien. Technische redaktion: christoph Janda (geologische Bundesanstalt). lektorat: christian cermak (geologische Bundesanstalt). cover: monika Brüggemann-ledolter (geologische Bundesanstalt). Verlagsort: Wien. Ziel der "abhandlungen der geologischen Bundesanstalt" ist die dokumentation und Verbreitung erdwissenschaftlicher forschungsergebnisse. satz, gestaltung und druckvorbereitung: peter ableidinger im auftrag der geologischen Bundesanstalt. druck: grasl druck & neue medien gmbh, Bad Vöslau. franz neubauer university of salzburg department of geography and geology hellbrunnerstraße 34, a-5020 salzburg, austria
The Ordovician of the Ebbe Inlier (Rhenish Massif, western Germany) revisited
GFF, 2014
Outcrops of Ordovician sediments in western Germany are of very limited extent. In the Ebbe Inlier (Rhenish Massif) strongly tectonized, mostly fine-grained detrital Middle to Upper Ordovician rocks have been described since the 1910s. These sediments underwent a careful revision in the last 20 years. Four formations, attributed to the Herscheid Group, yielded diverse fossil assemblages (including trilobites, graptolites, ostracods, chitinozoans, acritarchs and other groups) that allow attribution to age intervals between the Abereiddian (Darriwilian) and the Streffordian (early Katian). The sedimentary facies shows greatest resemblance to the successions of the Condroz Inlier in Belgium. Palaeogeographically, they constitute the southeasternmost part of eastern Avalonia.
Cretaceous Research, 2010
The ''An der Schanz quarry'' near Burgberg exhibits parts of the Helvetic Seewen Formation. Its base is dated as Cenomanian, its top as Late Santonian by planktonic foraminifera by previous authors. A re-sampling of the section for inoceramid and d 13 C stratigraphy gave an Early Coniacian age for the uppermost parts of the Seewen Formation. A literature review suggests that the top of Seewen Formation of the Allgä u (Bavaria) and Vorarlberg (Austria) is never younger than the Middle or terminal Middle Coniacian. d 13 C data confirm the biostratigraphic dating by inoceramids. Furthermore, although only 28 m thick, the section exhibits all important d 13 C events for interbasinal correlation previously recognized in sections of England and northwestern Germany. The d 13 C calibration of the LO of H. helvetica is shown to be diachronous and not of value for isochronous zonations. The Caburn d 13 C event is suggested as a marker for the Middle-Upper Turonian boundary due to the concomitant FO of I. perplexus. The re-dating of the facies turnover from a calcareous biosedimentary system towards a marl dominated system (succeeding Amden Formation) is briefly compared with the situation observed in northwestern Germany, where comparable trends are mapable.
Newsletters on Stratigraphy
For Oligocene and Miocene sediments of the Central Paratethys realm, regional chronostratigraphic stages have been defined on the basis of characteristic faunal assemblages, often containing abundant endemic elements. Although considerable progress has been made in correlating Paratethyan stages with the Global Time Scale (GTS), the task remains incomplete, especially for the Early Miocene period. The present study focuses on Lower Miocene deposits of the Central Paratethys in southeastern Germany, i. e. the Upper Marine Molasse (OMM) and Upper Brackish Molasse (OBM) of the North Alpine Foreland Basin (NAFB, Molasse Basin). The sediments concerned are assigned to the regional Ottnangian stage of the Central Paratethys, which corresponds to the middle Burdigalian in the GTS. We present a formal lithostratigraphic definition of the Untersimbach and Neuhofen Formations (both OMM), combined with litho-, bio-and magnetostratigraphic investigations, which together provide an improved chronology for the middle Burdigalian interval in the NAFB. The base of the Ottnangian stage is shown to correlate with polarity chron C5En, and we consider an absolute age of around 18.2 Ma to be most plausible. As the OMM in the southeast German part of the NAFB represents a single transgressive-regressive sequence, our new data suggest that the Ottnangian transgression began during chron C5En (~18.2 Ma), whereas the onset of the regressive phase lies within chron C5Dr.2r (~18 Ma). The uppermost marine deposits (top OMM/"Glaukonitsande & Blättermergel") and the lowermost brackish sediments (OBM/Oncophora Formation) are correlated with polarity chron C5Dn (~17.4 Ma). Moreover, our results clearly demonstrate that the lower Oncophora Formation (normal polarity) is not time-equivalent to the OBM/Kirchberg Formation in the southwest German sector of the NAFB (largely reverse polarity) as has hitherto been assumed. The lower Oncophora Formation is most probably contemporaneous with the lowermost OBM sediments (Grimmelfingen Formation) in the southwest German Molasse Basin.
Sedimentary Geology, 2007
During the Oxfordian, Bahamian-type shallow-water carbonates formed in the Lower Saxony Basin of North Germany. The outcrop of the Korallenoolith Formation in a quarry in the Ith Mountains (Lauensteiner Pass) contains a series of well-exposed coral and coral-microbial reefs intercalated with oolites. Six different facies are distinguished, which can be assigned to the inner part of a carbonate ramp. Based on textural variations and facies stacking patterns, accommodation space to sediment supply and/or sediment production cycles of different hierarchies were defined in this succession. A multispectral outcrop gamma-ray log was measured as additional tool to separate facies and to identify the cyclicity. A good correlation between fluctuations in the gammaray log and the lithological changes exists. Generally, coral and coral-microbial reefs reflect times of higher available accommodation space, oolites indicate sedimentation in shallower waters. We thus show how, based on sequence stratigraphy, the succession of the Korallenoolith Fm can be subdivided into genetic packages. This approach may contribute in providing a tool for a firm high resolution correlation of the different outcrops of this formation, which is presently only poorly constrained. The good correlation between gamma-ray log and the cyclicity may also be helpful for subsurface correlations in the Lower Saxony Basin.
Palaeobiodiversity and Palaeoenvironments, 2022
The Borkewehr section near Balve at the southeastern end of the Remscheid-Altena Anticline is currently the best and most complete Devonian/Carboniferous Boundary (DCB) succession of the Rhenish Massif, Germany. Based on a multidisciplinary approach, focusing on refined conodont and ammonoid biostratigraphy, microfacies analyses, sequence stratigraphy, carbon isotopes (C org and C carb), trace element geochemistry, including REE data, and cyclostratigraphy, the section is proposed as a candidate for the new basal Carboniferous GSSP. The succession represents a pelagic "seamount" setting. It spans the upper Famennian to lower Viséan, with a condensed development of most Rhenish lithostratigraphic units and sedimentary sequences. It is the type-section of the oxic and strongly cyclic, fossiliferous Wocklum Limestone and of important uppermost Famennian and basal Carboniferous index species. The First Appearance Datum (FAD) of Protognathodus kockeli s.str., in a phylogenetic succession from the ancestral Pr. semikockeli n. sp., is proposed as future GSSP level. This FAD is sandwiched between many other marker levels for global correlation. Below are, from base to top, the transgressive base of the at least partly anoxic Hangenberg Black Shale (base Lower Hangenberg Crisis Interval), the Hangenberg Regression (onset of siltstones of the basal Middle Crisis Interval), the level of maximum regression, indicated by maximum Zr/Al values, and the initial transgression of the basal Upper Crisis Interval, marked by the re-onset of carbonate deposition. Above follow the locally cryptogenic FAD of Siphonodella (Eosiphonodella) sulcata s.l. at the base of the post-Crisis Interval (Hangenberg Limestone), associated with a conodont biofacies shift, the FAD of Si. (Eo.) bransoni, and, much higher, the sharp This article is a contribution to the special issue "The Rhenish Massif: More than 150 years of research in a Variscan mountain chain" This article is registered in Zoobank under: urn:lsid:zoobank.org:pub: 1CB2D489-2188-4C27-B8F6-261C3C355EC1
Structural geology and sedimentology of the Heiligenhafen till section, Northern Germany
Quaternary Science Reviews, 1999
Three Pleistocene tills can be distinguished in a coastal cli! section near Heiligenhafen, northern Germany, on the basis of structural and petrographic characteristics. The Lower and Middle Tills had previously been ascribed to the Saalian, and the Upper Till to the Late Weichselian. The former two tills are folded, and unconformably overlain by the Upper Till. In this paper, structural and sedimentological observations are used to investigate whether the Lower and Middle Tills belong to one glacial advance, or two separate (Saalian) advances, as was suggested in earlier studies based on "ne gravel stratigraphy.
Geomorphology, 2018
This study reports on neotectonic deformation represented as faults, graben, and horst structures, which have been found in the uppermost 10 m of Quaternary sediments, consisting mainly of Saalian glaciofluvial and Weichselian periglacial material in northern Germany that is generally considered as a low-seismicity area. An area with up to 35 faults in a 60 m wide zone exhibits mainly extensional structures. Most of those are SE-NW-oriented and in some cases NE-SW. Soft sediment deformation structures include sand blows, blowout-related infill structures, and growth faults. Small-scaled, soft-sediment deformation structures are also found. Based on the large size of the sand blows and the widespread occurrence of small-scaled, soft-sediment deformation structures, the magnitude of the earthquakes is estimated in the order of M ≥ 5.5. Single faults exhibit a displacement of a few metres. Because some faults are overlain by unfaulted sandur sediments the system has been active over at least~200 ka (Saalian). Several faults extend through the Weichselian periglacial layer to the present ground surface, proving ongoing deformation during the Weichselian Lateglacial and/or the Holocene. This major activity during the Saalian and the Weichselian points to the activation of old tectonic structures. A possible process can be the glacial loading and unloading associated with the isostatic rebound. Holocene and late Holocene seismic events are shown by the penetration of the Weichselian-Lateglacial periglacial layer by faults and sand blows as well as a possible blowout-related bowl with organic material and corresponding young 14 C dates of b300 a cal 14 C. The documented fault zone could possibly be attributed to an intraplate pre-Quaternary fault within the central Glückstadt Graben. Concurrent adjacent faults are assumed from the morphology.