Carbonate platform facies reflected in carbonate basin facies (Triassic, northern Calcareous Alps, Austria)

Facies ◽  
1991 ◽  
Vol 25 (1) ◽  
pp. 253-277 ◽  
Author(s):  
John J. G. Reijmer ◽  
Juliana S. L. Everaars
Keyword(s):  
Carbonate Platform ◽  
Northern Calcareous Alps ◽  
Northern Calcareous

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 Neomeris mokragorensis sp. Nov. (Calcareous alga, Dasycladales) from the cretaceous of Serbia, Montenegro and the Northern calcareous Alps, (Gosau group, Austria)

2007 ◽  
pp. 39-51 ◽  
Author(s):  
Rajka Radoicic ◽  
Felix Schlagintweit
Keyword(s):  
New Species ◽  
Carbonate Platform ◽  
Northern Calcareous Alps ◽  
Northern Calcareous ◽  
Calcareous Alga ◽  
Gosau Group ◽  
Mirdita Zone

The new species of the genus Neomeris - Neomeris mokragorensis sp. nov. described in this paper from western Serbia originates: from the Albian of Mokra Gora (the succession transgrading on the serpentinite) and from the Turonian of the Skrapez-Kosjeric area (the succession transgrading on the Carboniferous). The presence of this species has been noted in the Turonian of the Kukes and in the Santonian of the Metohija Cretaceous Unit (Mirdita Zone). In the surrounding of Podgorica (Dinaric Carbonate Platform, Montenegro), the same species previously was presented as Neomeris cf cretacea STEINMANN. Well preserved Neomeris specimens from the Turonian to the Santonian strata of the Northern Calcareous Alps (Gosau Group, Austria) previously described as Neomeris circularis BADVE & NAYAK, is assigned to Neomeris mokragorensis sp. nov. Neomeris mokragorensis is characterized by a thin loosed skeleton formed only around ampullae, by which, besides the form of the ampullae, this species is clearly distinct from Neomeris cretacea (Steinmann).

Growth of carbonate platforms controlled by salt tectonics (Northern Calcareous Alps, Austria)

2020 ◽  
Author(s):  
Philipp Strauss ◽  
Jonas Ruh ◽  
Benjamin Huet ◽  
Pablo Granado ◽  
Josep Anton Muñoz ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Carbonate Platform ◽  
Northern Calcareous Alps ◽  
Rheological Parameters ◽  
Basin Evolution ◽  
Controlled Growth ◽  
Carbonate Platforms ◽  
Vienna Basin ◽  
Northern Calcareous ◽  
Salt Mines

<p>The Mid Triassic section of the Northern Calcareous Alps (NCA) is dominated by carbonate platforms, which grew diachronously on the Neo-Tethys shelf beginning in the Middle Anisian and ending in Lower Carnian times. The platforms grew isolated in previous deeper marine settings with high growth rates reaching 1.5 to 2 mm per year. The concept of self-controlled growth of carbonate systems on salt changes the understanding of Mid-Triassic NCA sedimentology. Conceptual models of the carbonate platform growth were done based on field observations, construction of cross-sections and subsidence analysis of selected carbonate mini-basins. To satisfy the observed boundary conditions of platforms growth in respect of timing, water depth and basin evolution, fast accumulation rates have to be assumed best represented by salt deflation and down-building of carbonate minibasins. A feedback loop of carbonate growth (creating a load gradient) and subsidence by salt evacuation initiates once the pre-kinematic layer reaches the sea level and the first layer of carbonate is produced. An initial phase of fast carbonate aggradation ends once the salt below the platform is fully evacuated and the minibasin is primary welded.</p><p>To further analyse and quantify boundary conditions necessary for the observed carbonate mini basin evolution, a series of thermo-mechanical numerical experiments were conducted. The density and rheological parameters for rock salt applied in the experiments were mainly gathered from observations and mechanical experiments on salt from salt mines and from an exploration well by OMV in the Vienna Basin. The numerical simulations essentially support the concept of down-building carbonate platforms. Self-controlled growth of carbonate systems on salt allows a completely new perspective to understand Mid-Triassic NCA carbonate platforms and their boundary conditions, such as the accumulation of thick carbonates (>1.5 km) without basement faulting, the isolated growth of platforms, or the transition of aggradational to progradational growth.</p>

scholarly journals Dachstein-type Avroman Formation: An indicator of the Harsin Basin in Iraq

GeoArabia ◽  
2015 ◽  
Vol 20 (4) ◽  
pp. 17-36
Author(s):  
Agoston Sasvari ◽  
Laura Davies ◽  
Andrew Mann ◽  
Jawad Afzal ◽  
Gabor Vakarcs ◽  
...  
Keyword(s):  
Depositional Environment ◽  
Carbonate Platform ◽  
Tectonic Setting ◽  
Upper Triassic ◽  
Northern Calcareous Alps ◽  
Late Triassic ◽  
Northern Calcareous ◽  
Marine Sedimentation ◽  
Tectonic Position ◽  
Arabian Platform

ABSTRACT A field survey was carried out in 2012 focusing on the tectonic position and the role of Upper Triassic (Upper Norian–Rhaetian) Avroman Formation outcrops located in the Zalm area of Iraq, close to the Iraq-Iran border. At this location, the Cretaceous chert-bearing strata of the Qulqula Formation are overlain by sheared mafic bodies, which are in turn topped by the cliffs of the megalodontaceae-bearing Upper Triassic Avroman Formation. Similarities in lithology, sequence and tectonics position, suggest that the Triassic section of the Bisotoun Unit from the Kermanshah Zone of Iran can be used as a tectonic analogue of the Avroman Formation. According to our model, both the Avroman and the Bisotoun units formed an intra-oceanic carbonate platform, built-up by a characteristic megalodontaceae-bearing carbonate platform assemblage during the Late Triassic. The Harsin oceanic basin, which separated the Avroman-Bisotoun Platform from the Arabian Platform, was characterised by deep-marine sedimentation, the remnants of which form the Qulqula Formation in Iraq, and the Radiolaritic Nappe and the Harsin Mélange in the Kermanshah Zone. This tectonic setting is not unique; numerous authors suggest the existence of an oceanic rim basin, separating carbonate platform units (e.g. Oman ‘exotics’) from the Arabian Platform. The age of the deformation could be Late Cretaceous (Maastrichtian), but using analogues from Iran, a Palaeogene deformation also seems possible. The Avroman Formation was interpreted to be a Dachstein-type sediment, similar to the well-studied Dachstein Formation of the Northern Calcareous Alps, Austria. Rock units, with similar lithology, or identical depositional environment and macroscopic fauna, were described by numerous authors along the Neo-Tethys suture zone from Austria to Japan, and from several tectonic units along the Panthalassa margin. The implication of this correlation is important for future studies: using well-described type localities of the marine units from the Northern Calcareous Alps as a reference, it is possible to significantly extend the available background knowledge, and to gain better insight into the Triassic regional depositional environment of the Middle East.

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