The nappe structure of the central Northern Calcareous Alps and its disintegration during Miocene tectonic extrusion?a contribution to understanding the orogenic evolution of the Eastern Alps

2003 ◽  
Vol -1 (1) ◽  
pp. 1-1 ◽  
Author(s):  
W. Frisch ◽  
H.-J. Gawlick
Keyword(s):  
Eastern Alps ◽  
Northern Calcareous Alps ◽  
Northern Calcareous ◽  
Tectonic Extrusion

The Graptolitic Faunas of the Gotlandian in the Eastern Alps and their Relationships

1934 ◽  
Vol 71 (6) ◽  
pp. 268-275 ◽  
Author(s):  
Franz Heritsch
Keyword(s):  
Rapid Development ◽  
Eastern Alps ◽  
Northern Calcareous Alps ◽  
Carnic Alps ◽  
Northern Calcareous ◽  
Southern Margin ◽  
The Alps ◽  
The University ◽  
The Great War ◽  
Surprising Discovery

The years that followed the Great War saw a rapid development in knowledge of the graptolitic faunas of the Eastern Alps. Professor M. Gortani described many graptolites from the Carnic Alps, and papers from the Geological Department of the University of Graz dealt with the same subject, as well as the distribution of the graptolites over a wider area of the Eastern Alps. Especially noteworthy was the surprising discovery of graptolites in the so-called grauwacke zone of the Alps, which follows the southern margin of the Northern Calcareous Alps. In the grauwacke zone, which consists of Palaeozoic and more ancient strata, more or less metamorphosed, graptolites were found at the following localities, (a) Fieberbrunn in the Tyrol (1), where the zones of Monograptus cyphus to M. turriculatus are found, and the presence of M. priodon indicates that higher zones may occur; (b) environs of Eisenerz in Styria (2), where the zones of M. gregarius to M. griestoniensis are found, as well as the zone of M. nilssoni; (c) Montavon in Vorarl-berg (29), where a badly-preserved specimen of Monograptus, possibly M. priodon, was discovered.

scholarly journals Ophiolitic detritus in Kimmeridgian resedimented limestones and its provenance from an eroded obducted ophiolitic nappe stack south of the Northern Calcareous Alps (Austria)

2015 ◽  
Vol 66 (6) ◽  
pp. 473-487 ◽  
Author(s):  
Hans-Jürgen Gawlick ◽  
Roman Aubrecht ◽  
Felix Schlagintweit ◽  
Sigrid Missoni ◽  
Dušan Plašienka
Keyword(s):  
Late Jurassic ◽  
Carbonate Platform ◽  
Eastern Alps ◽  
Northern Calcareous Alps ◽  
Western Carpathians ◽  
Chrome Spinel ◽  
Geochemical Composition ◽  
Northern Calcareous ◽  
Tectonic Processes ◽  
Building Process

Abstract The causes for the Middle to Late Jurassic tectonic processes in the Northern Calcareous Alps are still controversially discussed. There are several contrasting models for these processes, formerly designated “Jurassic gravitational tectonics”. Whereas in the Dinarides or the Western Carpathians Jurassic ophiolite obduction and a Jurassic mountain building process with nappe thrusting is widely accepted, equivalent processes are still questioned for the Eastern Alps. For the Northern Calcareous Alps, an Early Cretaceous nappe thrusting process is widely favoured instead of a Jurassic one, obviously all other Jurassic features are nearly identical in the Northern Calcareous Alps, the Western Carpathians and the Dinarides. In contrast, the Jurassic basin evolutionary processes, as best documented in the Northern Calcareous Alps, were in recent times adopted to explain the Jurassic tectonic processes in the Carpathians and Dinarides. Whereas in the Western Carpathians Neotethys oceanic material is incorporated in the mélanges and in the Dinarides huge ophiolite nappes are preserved above the Jurassic basin fills and mélanges, Jurassic ophiolites or ophiolitic remains are not clearly documented in the Northern Calcareous Alps. Here we present chrome spinel analyses of ophiolitic detritic material from Kimmeridgian allodapic limestones in the central Northern Calcareous Alps. The Kimmeridgian age is proven by the occurrence of the benthic foraminifera Protopeneroplis striata and Labyrinthina mirabilis, the dasycladalean algae Salpingoporella pygmea, and the alga incertae sedis Pseudolithocodium carpathicum. From the geochemical composition the analysed spinels are pleonastes and show a dominance of Al-chromites (Fe3+–Cr3+–Al3+ diagram). In the Mg/(Mg+ Fe2+) vs. Cr/(Cr+ Al) diagram they can be classified as type II ophiolites and in the TiO2 vs. Al2O3 diagram they plot into the SSZ peridotite field. All together this points to a harzburgite provenance of the analysed spinels as known from the Jurassic suprasubduction ophiolites well preserved in the Dinarides/Albanides. These data clearly indicate Late Jurassic erosion of obducted ophiolites before their final sealing by the Late Jurassic–earliest Cretaceous carbonate platform pattern.

scholarly journals Conodont thermometry by Raman spectroscopy on carbonaceous material: a case study from the Northern Calcareous Alps (Mürzalpen Nappe, Eastern Alps)

2020 ◽  
Vol 113 (1-2) ◽  
pp. 201-210
Author(s):  
Gerd Rantitsch ◽  
Gerhard Bryda ◽  
Hans-Jürgen Gawlick
Keyword(s):  
Raman Spectroscopy ◽  
Spectral Characteristics ◽  
Carbonaceous Material ◽  
Eastern Alps ◽  
Northern Calcareous Alps ◽  
Carbonaceous Matter ◽  
Northern Calcareous ◽  
Temperature Range ◽  
Color Alteration

AbstractCarnian metapelites from the southeastern segment of the Mürzalpen Nappe (Northern Calcareous Alps, Eastern Alps) were heated to 280-310 °C, estimated by Raman spectroscopy of carbonaceous material (RSCM). This temperature range is correlated to a Color Alteration Index of 5.0-6.5, determined on conodonts from adjacent Anisian to Norian carbonates. Average RSCM temperatures estimated on the conodonts are biased towards higher temperatures. The spectral characteristics of the conodont apatite suggest a composition altered during progressive recrystallization, influencing the band parameters of the included carbonaceous matter. Consequently, accurate conodont RSCM thermometry needs an assessment of apatite alteration.

scholarly journals Thrust tectonics in the Wetterstein and Mieming mountains, and a new tectonic subdivision of the Northern Calcareous Alps of Western Austria and Southern Germany

2021 ◽  
Author(s):  
Hugo Ortner ◽  
Sinah Kilian
Keyword(s):  
Eastern Alps ◽  
Northern Calcareous Alps ◽  
Main Body ◽  
Thrust Belt ◽  
Southeastern Part ◽  
Thrust Sheet ◽  
Northern Calcareous ◽  
Lateral Contact ◽  
Thrust Tectonics ◽  
Thrust Sheets

AbstractWe investigate the tectonic evolution of the Wetterstein and Mieming mountains in the western Northern Calcareous Alps (NCA) of the European Eastern Alps. In-sequence NW-directed stacking of thrust sheets in this thin-skinned foreland thrust belt lasted from the Hauterivian to the Cenomanian. In the more internal NCA major E-striking intracontinental transform faults dissected the thrust belt at the Albian–Cenomanian boundary that facilitated ascent of mantle melts feeding basanitic dykes and sills. Afterwards, the NCA basement was subducted, and the NCA were transported piggy-back across the tectonically deeper Penninic units. This process was accompanied by renewed Late Cretaceous NW-directed thrusting, and folding of thrusts. During Paleogene collision, N(NE)-directed out-of-sequence thrusts developed that offset the in-sequence thrust. We use this latter observation to revise the existing tectonic subdivision of the western NCA, in which these out-of-sequence thrusts had been used to delimit nappes, locally with young-on-old contacts at the base. We define new units that represent thrust sheets having exclusively old-on-young contacts at their base. Two large thrust sheets build the western NCA: (1) the tectonically deeper Tannheim thrust sheet and (2) the tectonically higher Karwendel thrust sheet. West of the Wetterstein and Mieming mountains, the Imst part of the Karwendel thrust sheet is stacked by an out-of-sequence thrust onto the main body of the Karwendel thrust sheet, which is, in its southeastern part, in lateral contact with the latter across a tear fault.

The origin of elevated low-relief surfaces in the Eastern Alps from geomorphic criteria and cosmogenic nuclide dating

2021 ◽  
Author(s):  
Gerit Gradwohl ◽  
Kurt Stüwe ◽  
Moritz Liebl ◽  
Jörg Robl
Keyword(s):  
Eastern Alps ◽  
Northern Calcareous Alps ◽  
Glacial Erosion ◽  
Field Mapping ◽  
Northern Calcareous ◽  
Cosmogenic Nuclide ◽  
Cave Sediments ◽  
Cosmogenic Nuclide Dating ◽  
Longitudinal Channel

<p>Elevated low-relief surfaces are peculiar landforms found in many areas across the Eastern Alps, most notably on the plateaus of the Northern Calcareous Alps and the southern metamorphic ranges from Nock Mountains to Koralpe. Found in domains both glaciated and unglaciated during the Pleistocene, (peri-)glacial erosion as well as fluvial prematurity have been cited as two opposing models for their formation. In order to contribute to this debate, we present a map of the existing low-relief surfaces in the Eastern Alps, bridging both glaciated and unglaciated regions, using a combined effort of field mapping and GIS-based mapping. Hypsometric statistics and analysis of longitudinal channel profiles show clear differences between formerly glaciated, partly-glaciated and unglaciated regions and their relations to the mapped surfaces. Furthermore, the pace of late- to post-Miocene incision is quantified via cosmogenic nuclide dating (<sup>26</sup>Al, <sup>10</sup>Be, <sup>21</sup>Ne) of allogenic siliceous sediments from discrete elevations correlating with the low-relief surfaces, in particular from cave sediments in the Northern Calcareous Alps. This information can be used to demonstrate that low-relief surfaces in many unglaciated regions, but also in some glaciated regions can be interpreted in terms of pre-Pleistocene relict landscapes.</p>

scholarly journals Ophiolite derived material as parent rocks for Late Jurassic bauxite: evidence for Tithonian unroofing in the Northern Calcareous Alps (Eastern Alps, Austria)

2021 ◽  
Author(s):  
Timotheus Martin Christoph Steiner ◽  
Hans-Jürgen Gawlick ◽  
Frank Melcher ◽  
Felix Schlagintweit
Keyword(s):  
Shallow Water ◽  
Late Jurassic ◽  
Xrd Analysis ◽  
Eastern Alps ◽  
Major And Trace Elements ◽  
Parent Material ◽  
Northern Calcareous Alps ◽  
Carbonate Platforms ◽  
Northern Calcareous ◽  
Platform Margin

AbstractIn shallow-water limestones of the Plassen Formation in the Tirolic nappe of the Northern Calcareous Alps, bauxite was formed on karstified and tilted platform margin grainstones to boundstones around the ?Kimmeridgian/Tithonian boundary, or in the Early Tithonian as proven by Protopeneroplis striata Weynschenk, Labyrinthina mirabilis Weynschenk, and Salpingoporella pygmaea Gümbel. The platform established on top of the obducted ophiolite nappe stack. The onset of unroofing at the Kimmeridgian/Tithonian boundary exposed ophiolites to weathering, forming laterites, and bauxites. The weathered ophiolitic material was shed on the tilted, emerged, and karstified platform, where the bauxite accumulated. Continued subsidence led to flooding, and a Tithonian transgressive carbonate sequence sealed the bauxites. XRD analysis of the bauxite yields a composition of mainly boehmite with hematite and some berthierine, kaolinite, and chromite. SEM analysis verified magnetite, hematite, rutile, chromite, zircon, ferropseudobrookite, ilmenite, monazite, xenotime, and garnet distributed in pisoids and within the matrix. The pisoids reach a millimeter in size and partly show cores of older, larger pisoids. The composition of the chromites indicates an ophiolitic origin. Geochemical examination using major- and trace elements points to a mafic andesitic to basaltic parent material contaminated with highly fractionated rocks from an island arc. Formation of Early Tithonian bauxites in shallow-water limestones confirms Middle to Early Late Jurassic ophiolite obduction. This was followed by uplift and unroofing of the orogen from the Kimmeridgian/Tithonian boundary onwards after a period of relative tectonic quiescence with an onset of carbonate platforms during the Kimmeridgian on top of the nappe stack and the obducted Neo-Tethys ophiolites.

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