Abstract
Western Tethys sedimentary successions constitute fundamental archives of Late Triassic–Early Jurassic environmental, carbonate production and tectonic changes. During the Late Triassic, the Northern Calcareous Alps (Austria) belonged to the Western Tethys passive margin, characterised by the deposition of the early-dolomitized peritidal Hauptdolomit (Norian) adjacent basinward to the Dachstein carbonate shelf and passing upward to the mixed carbonate–siliciclastic Kössen Formation (Upper Norian–Rhaetian). The Kössen Fm. was subdivided into the lower shallow-water Hochalm Member and the upper Eiberg Member, accumulated in an intraplatform basin coeval to shallow-water carbonates (Upper Rhaetian Limestone). The Eiberg Mb. and overlying Jurassic strata were extensively studied as a continuous marine record across the Triassic/Jurassic boundary. In contrast, shallow-water successions, time-equivalent to the Eiberg Mb. and Upper Rhaetian Limestone, located North of the Eiberg Basin, are poorly investigated. This study focusses on the approximately 350 m thick Norian to Lower Jurassic succession cropping out in the eastern Northern Calcareous Alps (Stumpfmauer). The 32 distinguished lithofacies compose seven, vertically superimposed, sedimentary units (A–G), belonging to the Hochalm Mb. of the Kössen Fm. (Unit A peritidal cyclothems, Unit B claystone/marlstone with fossiliferous beds, Unit C coral boundstone to floatstone), Upper Rhaetian Limestone (Unit D subtidal cyclothems with claystone), shallow-water carbonate strata transitional to Lower Jurassic (Unit E ooidal coated grain peloidal grainstone with basal transgressive lag, Unit F bivalve-rich, microbialite and oncoidal lithofacies, previously attributed to the Upper Rhaetian Limestone) and Hettangian–Sinemurian Kalksburg Fm. (Unit G cross-laminated coated grain peloidal grainstone with quartz and chert). The detailed lithofacies characterisation presented in this study contributes to the knowledge on the Northern Calcareous Alps stratigraphy and depositional environments across the Triassic/Jurassic boundary. The identified sedimentary units can be framed in the evolution of Western Tethys and share similarities with depositional systems from the Western Carpathians, Transdanubian Range, Southern Alps and Dinarides suggesting coherent sedimentary response and environmental, climate and tectonic controls in different palaeogeographic domains.
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Introduction
Carbonate successions are unparalleled archives of global and local environmental, climate and accommodation changes responding through variations in depositional environments, vertical and lateral facies patterns and biota associations (Schlager 2003; Flügel 2004; Wright and Burgess 2005; Pomar and Hallock 2008). In Western Tethys, the Norian (Upper Triassic)–Jurassic sedimentary successions (Fig. 1) recorded changes in depositional regime and facies associations governed by sea-level oscillations, climate, biotic crisis and extensional tectonics (Flügel 2002; Krystyn et al. 2005; Gawlick et al. 2009; Kaufmann 2009; Berra et al. 2010). The end-Triassic mass extinction, one of the big five biotic crises, affected diverse marine and terrestrial groups and coincided with major changes in palynological assemblages (Sepkoski 1996; Hallam 2002; Hesselbo et al. 2002; Hillebrandt and Urlichs 2008; Ruhl et al. 2009; Clémence et al. 2010; McRoberts et al. 2012; Pálfy and Zajzon 2012; Richoz et al. 2012; Wignall and Atkinson 2020). This extinction was driven by environmental perturbations related to volcanic CO2 emissions of the CAMP basalts (Central Atlantic Magmatic Province; Marzoli et al. 2004). The study of Western Tethys Norian–Lower Jurassic successions in the Northern Calcareous Alps (NCA, Austroalpine, Austria; Figs. 1, 2) contributes to unravel the interplay of factors influencing carbonate sedimentary environments at a regional scale. In fact, from late Norian to early Jurassic, these depositional settings witnessed: (a) the demise of a long-lasting, hundreds of kilometres wide and over 1000 m thick, Norian early-dolomitized inner platform (Hauptdolomit) adjacent to hundreds of kilometres wide carbonate shelf (Dachstein Limestone and Reef); (b) a major late Norian–Rhaetian change in sediment supply with the input of fine siliciclastics, previously absent, alternating with carbonate strata (Hochalm and Eiberg members of the Kössen Formation), attributed to a change towards more humid climatic conditions (Berra et al. 2010); (c) the late Rhaetian development of intraplatform basins (Eiberg Basin; Golebiowski 1990; Kaufmann 2009; Mette et al. 2012; Krystyn et al. 2005; Restental Basin; Gawlick et al. 2009; Richoz et al. 2012; Hillebrandt et al. 2013), passing laterally to shallow-water carbonates (Oberrhätkalk/Upper Rhaetian Limestone; Schäfer 1979; Golebiowski 1990; Krystyn et al. 2005) with margins with coral patch reefs (Bernecker et al. 1999; Bernecker 2005; Kaufmann 2009) or distally steepened ramp with skeletal packstone/grainstone and mounds (Piller 1981; Stanton and Flügel 1989, 1995; Flügel 1981, 2002); (d) a sea-level fall followed by rapid rise and biotic turnover across the end-Triassic extinction event (McRoberts et al. 2012); (e) the late early Jurassic rifting leading to the opening of the Penninic Ocean (Bernoulli 1964; Eberli 1988; Gawlick et al. 2009).
The continuity of the Norian–Lower Jurassic succession cropping out in the NCA provides optimal conditions for the investigation of the sedimentary responses of shallow-water settings to some of the most significant environmental, climatic and tectonic changes affecting the Upper Triassic–Lower Jurassic stratigraphic record. Despite several studies performed on the Eiberg Basin in the western NCA (Hillebrandt et al. 2013), and on the Eiberg Basin southern margins (Upper Rhaetian Limestone; Stanton and Flügel 1989, 1995; Satterley et al. 1994; Bernecker et al. 1999; Tomašových 2006; Rizzi et al. 2020), shallow-water carbonate facies of the Kössen Fm. and Upper Rhaetian Limestone (time-equivalent to the Eiberg Basin), were not investigated in detail in the eastern NCA. To improve the knowledge on NCA stratigraphy and sedimentary evolution, the succession in the Stumpfmauer area (central eastern Austria; Fig. 2) was investigated for detailed facies characterisation and compared with other palaeogeographic domains of Western Tethys.
Geological setting of the NCA
The NCA (Fig. 2A) are a ~ 500 km long WSW–ENE-striking fold and thrust belt belonging to the Austroalpine domain (Tollmann 1976; Ratschbacher et al. 1989, 1991; Gawlick et al. 1999; Mandl 1999, 2000; Frisch et al. 2000; Frisch and Gawlick 2003; Schmid et al. 2004). The Triassic Austroalpine passive margin faced the Neo-Tethys to the E–SE (with ophiolite obduction in the Middle Jurassic; Gawlick et al. 2008). From the early–middle Jurassic, the Austroalpine became separated from Europe by the opening of the Penninic Ocean to the N–W (Gawlick and Missoni 2019). In the NCA, an Upper Permian to Eocene sedimentary succession is exposed, with the Triassic shallow-water carbonates representing the thickest deposits (Tollmann 1965, 1976, 1985; Mandl 2000; Krystyn et al. 2005). In this study, following Gawlick et al. (1999), the classical tectonic subdivision of the complex internal structure of the NCA in a lower Bavaric, intermediate Tyrolic and an upper Juvavic nappe group is used descriptively, without any structural significance of these units.
Upper Triassic–Lower Jurassic stratigraphy of the NCA
The Norian succession consists of thousands of square kilometres wide and more than 1000 m thick inner platform facies (Figs. 1B, C, 2B), pervasively early dolomitized, known as Hauptdolomit (Tollmann 1965, 1976, 1985; Fruth and Scherreicks 1982, 1984). This unit, with different lithostratigraphic names and some differences in the stratigraphic range, extends to the Western Carpathians, Transdanubian Range, Southern Alps, Dinarides and Southern Apennines (Iannace and Frisia 1994; Buckovic et al. 2001; Vlahović et al. 2005; Berra et al. 2010; Caggiati et al. 2018; Héja et al. 2018; Haas et al. 2022). Landward, the NCA Hauptdolomit interfingered with the Keuper shallow-marine hypersaline environments, with carbonate, siliciclastic and evaporite deposits. Basinward, the Hauptdolomit was adjacent to lagoonal subtidal–peritidal cyclic strata (Lofer cyclothems of the Dachstein Limestone; Fischer 1964; Enos and Samankassou 1998; Missoni et al. 2005), passing to the Dachstein Reef shelf margin (Fig. 1C). The Dachstein Reef (Flügel 2002; Bernecker 2005) faced the Hallstatt outer shelf of the Neo-Tethys Ocean (Matzner 1986; Kozur 1991; Gawlick et al. 1999; Gawlick and Böhm 2000; Köppen and Carter 2000). The Hauptdolomit is overlain by a well-bedded, 10–400 m thick, only partly dolomitized, carbonate unit, labelled as Plattenkalk (Steiner 1965a, b; Czurda and Nicklas 1970; Golebiowski 1989). Fruth and Scherreiks (1982, 1984) considered the Plattenkalk as part of the Hauptdolomit, representing its uppermost transitional calcareous portion.
Terrigenous input affected the carbonate shelf during the latest Norian–Rhaetian time with the deposition of the Kössen Fm., consisting of the Hochalm and the Eiberg members (Kuss 1983; Golebiowski 1989, 1990; Rizzi et al. 2020). The Hochalm Mb. represents an upper Norian–lower Rhaetian shallow-water succession, which was divided in four units by Golebiowski (1989). Units 1 and 2 (Lumachellen realm) consist of shallowing-upward cyclothems similar to those in the Hauptdolomit and Dachstein Limestone, at times capped by marlstone, indicative of an intertidal to open subtidal shelf. Unit 2 facies are similar to Unit 1 but indicative of more open marine conditions. The overlying Unit 3 is dominantly siliciclastic with marlstone and claystone alternating with metre-thick calcareous beds. Unit 3 documents a transgressive event at regional scale, corresponding to the maximum transgression of the Kössen Fm. onto the margin of the Dachstein Limestone shelf in the south, close to the Norian–Rhaetian boundary (Golebiowski 1989; Satterley 1996a, b). Unit 4 of the Hochalm Mb. is a massive, 10–20 m thick, laterally continuous unit rich in corals, labelled as Hauptlithodendronkalk (Suess and Mojsisovics 1868), Lithodendronkalk (Schlager and Schöllnberger 1974; Golebiowski 1989), or Korallenkalke (Kuss 1983) traceable for about 300 km across an E–W transect in the NCA (Golebiowski 1990). The overlying upper Rhaetian Eiberg Mb. represents deposition in an intraplatform basin of estimated water depth up to 150–300 m (Golebiowski 1990; Kaufmann 2009; Mette et al. 2012; Krystyn et al. 2005; Hillebrandt et al. 2013). The Eiberg Mb. is subdivided into 4 units, consisting of well-bedded bioclastic limestone rich in echinoderm debris passing upward to alternating calcareous mudstone and marlstone with Zoophycus burrows, documenting a deepening trend (Golebiowski 1989; Mette et al. 2012, 2016). The Eiberg Basin was lateral to shallow-marine carbonates (Oberrhätkalk/Upper Rhaetian Limestone; Figs. 1C, 2B) overlying the coral-rich Unit 4 of the Hochalm Mb. (Golebiowski 1990; Wegerer and Gawlick 1999; Bernecker 2005; Rizzi et al. 2020). The southern margin of the Eiberg Basin at the Steinplatte was interpreted as a distally steepened carbonate ramp formed by the deposition of autochthonous biogenic sediment (massive mound facies with bioclastic sand and shell coquinas) on an antecedent homoclinal ramp (Stanton and Flügel 1995; Flügel 2002), laterally adjacent to the Dachstein Limestone shelf (Kaufmann 2009).
The Triassic–Jurassic transition was affected by a sea-level fall followed by a long-term sea-level rise during the Hettangian (Kaufmann 2009; McRoberts et al. 2012), with the drowning of the Dachstein shelf (Gawlick et al. 2009; Gawlick and Missoni 2019). The early Jurassic extensional tectonics, leading to the opening of the Penninic Ocean, produced half-graben basins and structural highs (Bernoulli and Jenkyns 1974; Eberli 1988; Manatschal and Bernoulli 1999) with condensed successions accumulated on footwall highs (i.e. Kalksburg Fm., Adnet Fm., Hierlatz Limestone Mb., Allgäu Fm.) between the Hettangian and early Toarcian, followed by Middle–Upper Jurassic pelagic deposits (Ruhpolding Radiolarite Group; upper Bajocian–lower Tithonian; Eberli 1988; Böhm et al. 1995; Ebli 1997; Gawlick et al. 2009).
Stratigraphy of the study area
The study area between the Stumpfmauer and Esslingalm is part of the Königsberg syncline (Fig. 2; Mandl 2000; Schnabel et al. 2002; Strauss et al. 2020). Steiner (1965a, b, 1967) identified the following units above the Hauptdolomit, from base to top: (1) 100 m of partly dolomitized limestone beds, attributed to the Plattenkalk (uppermost Norian); (2) 30 m of marlstone alternating with highly fossiliferous limestone, labelled as Mergel- und fossilreiche Kössener Schichten (Kössen Beds, Rhaetian); (3) 60 m of well-bedded limestone with corals and marlstone (Kössener Schichten, Hauptlithodendronkalk, Mergellagen); (4) 2 m of crinoid-rich limestone (Krinoidenkalk marker bed, upper Rhaetian); (5) 30 m of oolitic limestone labelled by Steiner (1967) as Oberrhätkalk (heller, dickbankiger Oberrhät Oolithkalk, also reported as Pseudoolithkalk). According to Steiner (1967), in the study area, the Oberrhätkalk/Upper Rhaetian Limestone consists of micrite coated grains, aggregate grains, peloidal and ooidal grainstone facies. Nevertheless, the Upper Rhaetian Limestone in the southern margin of the Eiberg Basin includes coral and calcareous sponge reefs, reef mounds and bioclastic facies (Bernecker 2005; Krystyn et al. 2005; Kaufmann 2009). The Kreuss (2014) GEOFAST geological map (Fig. 2C) confirms the mapping proposed by Steiner (1967) and does not provide a nomenclature of the Lower Jurassic lithostratigraphic units.
Methods
The Norian–Lower Jurassic succession was investigated from the Esslingalm area to the Stumpfmauer peak in the Königsberg syncline (Figs. 2C, 3). Six stratigraphic logs (Figs. 4, 5) were measured: Log EA (103 m thick), Log EC (31 m thick), Log EG (54.7 m thick), Log EL (34.5 m thick), Log ED–EE (117.9 m thick) and Log EI (129.4 m thick). More than 330 thin sections were analysed through standard petrographic analysis. Staining with alizarin red and potassium ferricyanide (Dickson 1966) was performed to identify the presence of dolomite and ferroan calcite. Detailed information about sample location is reported in the Online Supplementary Information.
Results
The logged succession (Figs. 3, 4, 5) consists of 32 lithofacies types, labelled from F1 to F32 (Table 1). Associations of these lithofacies compose seven vertically superimposed sedimentary units, labelled from base to top as Units A–G (Table 2), spanning the upper Norian to lower Jurassic. The investigated sedimentary succession overlies hundreds of metres of massive to decimetre-thick beds of replacive fabric-retentive to destructive dolomite (Hauptdolomit) and partially dolomitized (Plattenkalk) peritidal inner shelf carbonates (Fig. 2C).
Unit A
Unit A includes lithofacies from F1 to F10 and F20. Bioturbated calci-mudstone with rare peloids and skeletal fragments (F1; Fig. 6A) can occur replaced by dolomicrite to anhedral non-planar dolomicrosparite (F1D), at the base of log EA (Fig. 4). Skeletal wackestone to packstone (F2), sometimes dolomitized (F2D), contains bivalves, gastropods, brachiopods, aulotortid foraminifera and reworked lithoclasts (Fig. 6B). Wackestone to packstone beds with ostracods (F3) are associated with centimetre-thick claystone intervals (Fig. 6C). Peloidal calci-mudstone/wackestone to packstone with fenestrae (F4) and laminated stromatolite boundstone (F5) alternate and occur capped by erosional surfaces (Fig. 6D–F). Lithofacies F6 represents skeletal wackestone/packstone to floatstone/rudstone with brachiopods and bivalves (including decimetre-size megalodontids), gastropods and aulotortid foraminifera (Fig. 6G). The label F7 is used to address all the fine-grained siliciclastic deposits (claystone, marlstone, argillaceous mudstone) forming millimetre, decimetre to metre-scale beds (Fig. 3B). Skeletal peloidal packstone (F8) includes bivalves, gastropods, foraminifera (aulotortids, duostominids, textulariids, Triasina hantkeni), and dasyclad algae (Fig. 6H). Bioturbated packstone with moulds of ooids with peloids as nuclei characterises lithofacies F9 (Fig. 7A). Grainstone beds with isopachous rims of fibrous marine cement (F10) contain micrite coated grains, radial ooids, aggregate grains, intraclasts, foraminifera (Aulotortus sp., Triasina hantkeni) and peloids (Fig. 7B). Unit A includes also beds of packstone/rudstone with reworked bioclasts, lithoclasts and intraclasts of lithofacies F1, F2, F4 and F5, overlying erosional surfaces (F20; Fig. 6D).
Unit A (38–55 m thick) is organised in vertically stacked, metre-scale (2–10 m thick) lithofacies packages (Fig. 4) with basal F1, F2, F3, F6, F8 and top F4, F5, F9, F10 separated by erosional surfaces, few millimetres to centimetres thick claystone (F7) and lithoclastic beds (F20; Fig. 6D). The lower boundary of Unit A with the Plattenkalk is transitional and placed at the first metre-scale intercalation of claystone, associated with the gradual disappearance of dolomitized beds, whereas the upper boundary with Unit B is sharp and marked by the onset of the ~ 50 m thick claystone/marlstone succession (F7).
Unit B
Unit B (Figs. 3A, B, 4) consists of brown to black claystone and marlstone (F7) alternating with 0.5–1 m thick calcareous beds (F11, F12). Lithofacies F11 consists of nodular beds of bioturbated skeletal wackestone/floatstone to packstone/rudstone with common bivalves, brachiopods, gastropods and echinoderms (Fig. 7C). Phaceloid coral boundstone to floatstone (F12) forms decimetre to metre-thick beds. Retiophyllia and Thecosmilia-type corals are sometimes encrusted by Bacinella-Lithocodium or serpulids and occur in marly skeletal wackestone/packstone with crinoids, brachiopods, rare calcareous and siliceous sponges and ammonoids (Figs. 7D, H, 8A).
Unit B is approximately 50 m thick but tectonic displacement prevents a reliable estimate of the thickness. The lower and upper boundaries are sharp (Fig. 3B).
Unit C
Unit C consists of metre-scale massive boundstone and floatstone with corals (F12, F13) associated with lithofacies F8, F11 and F20. Phaceloid corals form decimetre- to metre-scale colonies (Fig. 8B). Corallites are often encrusted by Bacinella-Lithocodium and surrounded by wackestone/packstone with bivalves, gastropods, brachiopods, calcareous and siliceous sponges (Fig. 8B, C); rare chert nodules are present.
Unit C (8–11 m thick) basal and top boundaries are sharp (Fig. 3B). Siliciclastic input is rare and occurs only at the base.
Unit D
Unit D consists of lithofacies F1, F2, from F6 to F20, and F22 organised in 2–5 m thick stacked lithofacies packages separated by metre-thick intervals of claystone/marlstone (F7; Fig. 5). Unit D distinctive lithofacies are: (a) packstone–wackestone to floatstone with oncoids and abundant aulotortid and Triasina hantkeni foraminifera (F14; Fig. 8D); (b) coated grain grainstone with cross-lamination, micrite coated Triasina hantkeni, molluscs and rare calcareous and siliceous sponges and corals with isopachous fibrous marine and meniscus and pendant cement (F15; Fig. 8E, F); and (c) bioturbated packstone with micrite coated grains, aggregate grains and peloids (F16; Fig. 8G). Rare packstone with peloids and micritic intraclasts (F17; Fig. 8H) forms decimetre-thick irregular beds. Bacinella-Lithocodium boundstone (F18) is characterised by clotted peloidal micrite, rare corals, siliceous and calcareous sponges and millimetre-wide, irregular-shaped voids filled by blocky sparite cement (Fig. 9A, B). Grainstone to rarely packstone with abundant aggregate grains contains micritized ooids and coated grains with micrite envelopes, bivalves, gastropods, Triasina hantkeni and Parafavreina (F19; Fig. 9C, D). Beds of packstone/rudstone with reworked intraclasts and lithoclasts overlie erosional surfaces (F20; Fig. 9E). Decimetre-thick beds of cross-laminated coated grain ooidal grainstone (F22) also occur.
Unit D is 80–110 m thick with the lower boundary with Unit C marked by a sharp transition from massive coral boundstone (F13) to several metres-thick oncoidal skeletal packstone/floatstone (F14). The upper boundary with Unit E is characterised by an erosional surface at the top of Unit D, overlying both coated grain grainstone with Triasina hantkeni (F15, Log EL; Fig. 4) and boundstone to floatstone with phaceloid corals associated with claystone (F12, Log ED; Fig. 5) with irregular dissolution vugs, vadose pendant and meniscus cement and red iron oxide stained micritic crusts (Fig. 8F).
Unit E
Unit E constitutes a prominent ridge, forming the crest of the Stumpfmauer (Fig. 3A). This unit (57 m thick) is subdivided into a lower and upper part. The lower part (13 m thick) is characterised by packstone/grainstone to rudstone beds (up to 1 m thick) with centimetre-size rounded lithoclasts, partially silicified, radial ooids, micrite coated grains, peloids, abundant crinoids and bivalves (F21; Figs. 9F–H, 10A). Lithoclasts are mostly ooidal grainstone (F22) with isopachous fibrous marine cement followed by meniscus and pendant cement. The F21 basal bed is overlain by claystone (F7) and fine-grained bioturbated peloidal packstone with siliceous sponge spicules (F23; Fig. 10B, C). The upper part of Unit E (45 m thick) consists of grainstone with aggregate grains (F19) and cross-bedded peloidal coated grain ooidal grainstone with bivalves and sparse quartz grains (F22). F22 can be divided in F22A, F22B and F22C, based on the dominant grain types. F22A is a fine- and medium-grained grainstone dominated by peloids (Fig. 10D); F22B includes peloids, micrite coated grains and radial ooids (Fig. 10E, F). F22C is dominated by radial ooids with isopachous fibrous cement, quartz grains and bivalves (Fig. 10G). Lithofacies F19 and F22 occur both in Units D and E but in Unit E, they lack aulotortid foraminifera.
The boundary with the underlying Unit D shows an abrupt lithofacies change, coinciding with an erosional surface (F15 in Log EL in Fig. 4, F12 and F7 in log ED in Fig. 5). The upper boundary with Unit F is sharp and marked by a rapid lithofacies change between cross-bedded peloidal ooidal grainstone with millimetre-size fenestral voids below (F22A; Fig. 10H) and dark grey bivalve wackestone/packstone to rudstone/floatstone above (F24; Figs. 3C, 5).
Unit F
Unit F (39 m thick; Fig. 5) is subdivided into two parts based on lithofacies associations. The lower part (7 m thick) consists of dark grey bioturbated bivalve wackestone/packstone to rudstone/floatstone with rare dasyclad algae (F24; Fig. 11A, B) and ostracod wackestone/packstone (F25; Fig. 11C). The upper part (32 m thick) is characterised by peloidal grainstone to packstone (F26) with micrite coated grains, oncoids, bivalves, gastropods, Thaumatoporella parvovesiculifera, Cayeuxia, and benthic foraminifera (textularids, possible Siphovalvulina, lituolids, Evertyciclammina praevirguliana; Fig. 11D–G). F26 is alternating with metre-thick massive microbial boundstone (F27; Figs. 11H, 12A) or oncoidal packstone/rudstone (F28; Fig. 12B), with evidence of dissolution vugs, pendant and meniscus cement. F27 microbial boundstone consists of leiolitic and clotted peloidal micrite with Cayeuxia, Thaumatoporella parvovesiculifera and millimetre-size cavities filled by peloidal micrite, isopachous rims of marine fibrous cement and blocky sparite (Figs. 11H, 12A).
Unit F overlies Unit E cross-bedded grainstone with fenestrae (F22A) with a sharp contact, possibly associated with an angular unconformity (Fig. 3C). The upper boundary with Unit G is also sharp and marked by F26 and F28 with centimetre-size black lithoclasts sharply overlain by the chert and sponge spicule packstone (F29; Fig. 12C) belonging to Unit G (Fig. 3D).
Unit G
Unit G is composed of lithofacies F29, F30, F31 and F32 with the dominance of F32 (Fig. 5). Red to dark grey, 20 cm thick siliceous sponge spicule packstone are sometimes completely silicified (F29; Fig. 12C) and overlain by packstone/grainstone with abundant detrital quartz grains to sandstone, echinoderm debris, micrite coated grains, angular lithoclasts and peloids (F30; Fig. 12D). Lithofacies F31 consists of massive to metre-scale beds of bioturbated skeletal wackestone with bivalves, gastropods, ostracods, peloids, benthic foraminifera (possible Siphovalvulina, Evertyciclammina praevirguliana), Thaumatoporella parvovesiculifera and Aeolisaccus (Fig. 12E). Lithofacies F32 is characterised by 10 to 40 cm thick cross-bedded and cross-laminated (bidirectional) peloidal, micrite coated grain grainstone with abundant crinoids, decimetre-size chert nodules, quartz grains and rare glaucony (Fig. 12F–H).
Unit G is 34 m thick; its lower boundary is represented by the first sponge spicule packstone with chert (F29; Fig. 3D). The upper boundary is marked by the sharp occurrence of red colour crinoidal rudstone to packstone (Fig. 2B, C).
Interpretation of sedimentary units and depositional models
The nearly 350 m thick sedimentary succession from Units A to G (Fig. 13) recorded the evolution of the depositional environments in a shallow carbonate shelf or low-angle ramp system (Figs. 14, 15), located north of the intraplatform Eiberg Basin, across the Triassic to Jurassic boundary. The stratigraphic succession from Unit A to G includes the Hochalm Mb. of the Kössen Fm., Upper Rhaetian Limestone, Schattwald Beds, shallow-water strata transitional to Lower Jurassic and the Hettangian–Sinemurian Kalksburg Fm. (Figs. 2, 13).
Unit A peritidal cyclothems
Unit A is organised in metre-scale shallowing-upward cyclothems, showing in the lower part subtidal restricted (F1, F2, F3) to open marine (F6, F8), low-energy environments passing upward to intertidal and supratidal lithofacies (F4, F5) or high-energy shoal grainstone deposits (F9, F10; Fig. 14). Cyclothems are bounded by erosional surfaces with fine siliciclastic input (F7), overlain by transgressive lags reworking the lithoclasts of the underlying lithofacies (F20). Fragmented skeletal biota (bivalves, brachiopods, corals) testify for marine currents and/or storm events in subtidal open marine environments (F6).
Unit A asymmetric peritidal cyclothems are similar in terms of internal facies organisation to the cycles in the Dachstein Limestone (Lofer facies), described by Fischer (1964) as deepening upward cycles. The Dachstein Limestone Lofer cycles have been investigated by several authors concluding that these cyclothems are the result of the interplay of autocyclicity, tectonic activity, sea-level oscillations and climatic variations (Satterly and Brandner 1995; Satterley 1996a, b; Enos and Samankassou 1998; Samankassou and Enos 2019). Unit A cyclothems differ from those of the Dachstein Limestone for the presence of millimetre to decimetre-thick F7 claystone/marlstone layers, overlying the erosional cycle boundary (Fig. 6D). The predominance of cyclothems with capping intertidal-supratidal or high-energy shoal lithofacies suggests a progradational trend at the scale of the high-frequency accommodation oscillations, as also suggested by Satterley (1996a, b) in the basal part of the Dachstein Limestone. Nevertheless, the whole Unit A records an upward trend towards more open marine conditions, with the upward decrease in occurrence and thickness of the intertidal–supratidal F4 and F5 lithofacies and the increase in thickness of the subtidal open marine F6. The transitional lower boundary between the Plattenkalk and Unit A with the gradual decrease of dolomitized beds might reflect a climate change from arid to more humid conditions. This is supported by the siliciclastic input and the reduced efficiency of the early dolomitization processes, similarly to what is documented in the Southern Alps at the top of the Norian Dolomia Principale (Berra et al. 2010).
The occurrence of Triasina hantkeni in Unit A confirms at least a late Norian age because of its stratigraphic distribution as late Norian–Rhaetian (Zaninetti et al. 1992; Maurer et al. 2008). On the basis of lithofacies character and stratigraphic position, Unit A corresponds to Units 1 and 2 of the Hochalm Mb. of the Kössen Fm. by Golebiowski (1990). Units 1 and 2 accumulated in a shallow-marine, restricted peritidal setting evolving upward to open-shelf conditions, affected by episodic terrigenous input and storm events (Kuss 1983; Golebiowski 1990), as observed in Unit A. In the Hochalm section, Units 1 and 2 are approximately 100 m thick and late Norian in age (Golebiowski 1990).
Unit B claystone/marlstone with fossiliferous beds
Unit B represents the thickest claystone and marlstone (F7) succession alternating with metre-scale fossiliferous packstone/rudstone to boundstone (Figs. 13, 14). F7 records the siliciclastic input in a low-energy subtidal environment with high turbidity, below storm wave base. The fossiliferous beds F11, rich in bivalves and brachiopods, might represent low to moderate-energy conditions below the fair-weather wave base and oscillating around the storm wave base (cf. Tomašových 2004, 2006). The F12 beds with phaceloid corals, calcareous and siliceous sponges encrusted by Bacinella-Lithocodium must have accumulated in shallower photic conditions, above storm wave base.
Unit B records a significant fine-grained siliciclastic input on the carbonate shelf, which could be related to a global climate change (Kaufmann 2009) responsible for a shift of climate belts during a cooling interval (Berra et al. 2010). Unit B corresponds to Golebiowski (1990) Unit 3 of the Hochalm Mb. of the Kössen Fm. that was interpreted as accumulated within an open subtidal shelf with terrigenous input in water depth > 20 m. This unit reflects the maximum extension of the Kössen Fm. towards the Dachstein Limestone shelf (Golebiowski 1989; Satterley 1996b). In the reference section, Unit 3 is 30 m thick and latest Norian–early Rhaetian in age (Golebiowski 1990), whereas in Rizzi et al. (2020), it is reported as early Rhaetian.
Unit C coral boundstone to floatstone
Unit C records the rapid expansion of phaceloid coral boundstone across the shelf coinciding with a decrease in siliciclastic input with respect to Unit B (Figs. 13, 14). Unit C was deposited in a low-energy environment, as inferred from the abundance of micrite matrix surrounding the corals. The presence of corals, rare dasyclad algae and Bacinella-Lithocodium in F13 suggests photic depths.
Unit C corresponds to a marker bed that can be traced across the NCA (Hauptlithodendronkalk Steiner 1967; Schlager and Schöllnberger 1974; Kuss 1983; Satterley 1996b) and coincides with the lower Rhaetian Unit 4 of the Hochalm Mb. of the Kössen Fm. (Golebiowski 1990).
Unit D subtidal cyclothems with claystone
Unit D sharply overlies Unit C coral boundstone; it is the thickest unit characterised by regular occurrences of metre-scale F7 claystone/marlstone alternating with diverse carbonate lithofacies from F1 to F22 (Figs. 13, 14). Calci-mudstone and bioclastic wackestone (F1, F2) are indicative of restricted low-energy subtidal deposition. Bioturbated packstone with oncoids, micrite coated grains, peloids, benthic foraminifera and microbial boundstone (F14, F16, F17, F18) represent subtidal, low- to moderate-energy, open marine, photic depositional environments as suggested by the occurrence of dasyclad algae (F14) and Bacinella-Lithocodium (F18). High-energy shoals, above effective wave base, are represented by grainstone with micrite coated grains, aggregate grains, micritized and radial ooids (F15, F19, F22A, F22C). Unit D shallowing-upward cyclothems consist of basal metre-scale intervals of claystone/marlstone (F7) overlain by low to moderate-energy bioturbated subtidal, skeletal packstone to wackestone beds (F1, F2, F6, F11–F14, F16–F18) evolving to high-energy coated grain skeletal grainstone (F15, F19, F22A, F22C). Cyclothems are capped by sharp erosional surfaces on subtidal lithofacies with centimetre-scale irregular karstic dissolution vugs overlain by claystone/marlstone (F7) and transgressive deposits reworking eroded lithoclasts (F20) filling the karstic dissolution cavities (Fig. 9E). Unit D is indicative of subtidal settings, periodically affected by subaerial exposure and fine siliciclastic input, but lacking deposition in intertidal and supratidal environments as in Unit A. The absence of intertidal-supratidal lithofacies could be related to non-deposition or erosion. The occurrence of subaerial exposure surfaces at the top of subtidal lithofacies is indicative of sea-level falls, probably related to high-frequency eustatic oscillations controlled by climate or tectonics (Satterley 1996a, b).
In the Eiberg Basin, SW of the study area, the Kössen Fm. strata overlying the coral boundstone bed (Unit 4 of the Hochalm Mb. by Golebiowski 1990; Unit C in this study) correspond to deposition in an intraplatform basin (Eiberg Mb. of the Kössen Fm.; Golebiowski 1990). According to Golebiowski (1990, 1991), the shallow-marine successions resting upon Unit 4 coral boundstone, lateral to the Eiberg Basin, constitute the Oberrhätkalk/Upper Rhaetian Limestone. Hence, following Golebiowski (1990), Unit D in this study overlies Unit C coral boundstone and corresponds to the Upper Rhaetian Limestone, time-equivalent to the Eiberg Mb. and the Steinplatte complex facing the southern margin of the Eiberg Basin (Fig. 1C). Unit D lithofacies are similar to those described as Upper Rhaetian Limestone in the Bavarian Calcareous Alps, rich in Triasina hantkeni and with evidence of vadose meteoric cement (Schott 1983, 1984). In the geological maps by Schnabel et al. (2002) and Kreuss (2014), Unit D is mapped as Kössen Fm. and it is overlain by ooidal grainstone (Unit E in this study) mapped as Oberrhätkalk/Upper Rhaetian Limestone (Figs. 2, 13). Unit D upper boundary displays the evidence of vadose meteoric diagenesis due to subaerial exposure in different locations, at a present-day distance of 0.5 km (Figs. 4, 5, 13), that could be related to the regional sea-level fall associated with the onset of the end-Triassic extinction event (Satterley et al. 1994; Bernecker et al. 1999; Kaufmann 2009; McRoberts et al. 2012). This event was followed by the latest Rhaetian–Hettangian transgression passing to more open marine conditions (Delecat et al. 2011).
Unit E ooidal coated grain peloidal grainstone with basal transgressive lag
The basal part of Unit E with lithoclastic crinoidal ooidal packstone/grainstone to rudstone (F21) reworking clasts of ooidal grainstone affected by vadose meteoric diagenesis (e.g. meniscus, pendant cement, red matrix with iron oxide) represents a transgressive lag overlying an erosional surface at the top of Unit D, suggesting the reflooding of a subaerially exposed, shallow shelf and the presence of a stratigraphic gap between Unit D and E. The overlying claystone/marlstone (F7) and peloidal packstone with sponge spicules (F23) are indicative of low-energy, below storm wave base deposition. The upper part of Unit E consists of cross-bedded peloidal coated grain ooidal grainstone with bivalves, Parafavreina and quartz grains (F22) representing high-energy shoals, above wave base characterised by the first input of sand-grade quartz grains that will become abundant in the overlying Unit G.
The lower part of Unit E (F21, F7, F23) could be interpreted as the transgressive deposition, followed by the progradation of ooidal coated grain peloidal grainstone shoal (F22). The top of Unit E records a shallowing-upward trend to intertidal conditions, as documented by fenestrae in the uppermost peloidal grainstone (F22A; Fig. 10H), just below the contact with the bivalve packstone to rudstone (F24) of Unit F (Figs. 3C, 11A, B). In Unit E, benthic foraminifera as Aulotortus sp. and Triasina hantkeni, common in Unit D lithofacies F14 and F15 and indicative of Rhaetian age, were not identified.
In the Schnabel et al. (2002) and Kreuss (2014) geological maps (Fig. 2), Unit E is mapped as Oberrhätkalk/Upper Rhaetian Limestone, following the attribution by Steiner (1967). Strauss et al. (2020) instead mapped Unit E as Kössen Fm., not distinguishing the Kössen Fm. from the Upper Rhaetian Limestone. Unit E overlies an 80–110 m thick succession of subtidal cyclothems (Unit D) that, in this reconstruction, is attributed to the Upper Rhaetian Limestone. Unit E postdates a laterally extensive, subaerial exposure at the top of Unit D that could correspond to the end-Triassic sea-level fall associated with the extinction event (McRoberts et al. 2012; Hillebrandt et al. 2013) and does not contain any biostratigraphic marker indicative of Rhaetian age (i.e. Aulotortus sinuosus, Triasina hantkeni). Hence, Unit E may represent the Oberrhätkalk/Upper Rhaetian Limestone time-equivalent to the Steinplatte and Adnet platform margin as originally mapped by Steiner (1967) and maintained in recent geological maps (Schnabel et al. 2002; Kreuss 2014; Strauss et al. 2020) but, as presented in this study, it could most likely correspond to a younger shallow-water succession transitional to the lower Jurassic, post-dating the end-Triassic extinction and sea-level fall. This revised stratigraphy would result similar to what described in the western NCA, where the top of the Kössen Fm. is marked by subaerial exposure, overlain by the uppermost Rhaetian Schattwald Beds, followed by the Hettangian Löruns oolite (McRoberts et al. 1997; Felber et al. 2015).
Unit F bivalve-rich, microbialite and oncoidal lithofacies
The low-diversity, low-energy bivalve- and ostracod-rich lithofacies (F24–F25), overlain by microbialite and oncoidal peloidal lithofacies (F26–F28), suggest a stressed environment, scarce in skeletal biota, possibly related to the aftermath of the end-Triassic extinction. Unit F lithofacies represents shallow, low-energy restricted (F24, F25, F27, F28) to moderate-energy (F26) depositional settings within the photic zone. The presence of meniscus cement and reworked lithoclasts in F26 and F28 suggests events of subaerial exposures followed by transgressions. As for Unit E, Unit F is mapped as Upper Rhaetian Limestone in the Schnabel et al. (2002) and Kreuss (2014) geological maps. However, the presence of Aeolisaccus, lituolid foraminifera as Evertyciclammina praevirguliana, Thaumatoporella parvovesiculifera and putative Siphovalvulina supports an early Jurassic age. The stratigraphic data from this study suggest that Unit F may correspond to a shallow-water inner shelf succession, possibly time-equivalent to the lower Jurassic part of the Kendlbach Fm. in other areas of the NCA. Microbialites with siliceous sponges are described in the Hettangian strata overlying the southern margin and slope into the Eiberg Basin in the outcrops in Adnet and Steinplatte (Schöll Fm.; Delecat and Reitner 2005; Delecat et al. 2011).
Unit G cross-laminated coated grain peloidal grainstone with quartz and chert
Unit G starts with sponge spicule packstone with chert (F29), suggesting a deepening with respect to the underlying oncoidal lithofacies F28 of Unit F (with evidence of subaerial exposure at the top) and records a significant input of detrital quartz (F30). The coated grain peloidal grainstone with crinoids, quartz grains and chert (F32) represents a mixed carbonate–siliciclastic open marine shelf affected by bidirectional tidal currents. Cross-laminated coated grainstone beds (F32) are attributed to the Kalksburg Fm. (Hettangian–Sinemurian; Fig. 2B).
The deepening trend documented by Unit G may reflect the onset of the extensional tectonics associated with the opening of the Penninic Ocean, recorded in different Lower Jurassic successions of the NCA (Gawlick et al. 2009). Drowning of the shelf is marked by the overlying red crinoidal rudstone with ammonites and belemnites belonging to the Hierlatz Limestone Member of the Adnet Fm. and the Allgäu Fm. (Figs. 1 C, 15).
Discussion
The lithofacies characterisation and stratigraphic reconstruction of the Upper Triassic–Lower Jurassic succession in the Stumpfmauer study area provide detailed data for comparisons with coeval sedimentary successions in Western Tethys (Fig. 1) and for improving the understanding of the Tethyan depositional settings across the Triassic/Jurassic boundary.
Comparisons across Western Tethys
The investigated shallow-water Norian–Rhaetian to lower Jurassic lithofacies types and the superimposed sedimentary units display similarities with time-equivalent examples in the western NCA (McRoberts et al. 1997), Western Carpathians (Tomašovych 2004), Transdanubian Range (Vörös and Galácz 1998; Héja et al. 2018; Haas et al. 2022), Dinarides (Buckovic et al. 2001), Central Austroalpine (Furrer 1981; Berra and Cirilli 1997) and Southern Alps (Jadoul et al. 2004, 2005; Masetti et al. 2017).
Specifically, in the Western Carpathians, the Rhaetian Fatra Fm. consists of mixed carbonate–siliciclastic deposits with high lateral facies variability (Tomašovych 2004). Superimposed peritidal and shallow subtidal carbonate lithofacies and dark colour skeletal marlstone accumulated in inner-middle ramp to intraplatform basin settings under the influence of storm events (Tomašovych 2004). The Fatra Fm. lithofacies associations are similar to those recognised in the Hochalm Mb. of the Kössen Fm. and described in Units A, B, and C in this study. The abundance of calcareous sponges associated with corals in the Fatra Fm. suggests more stressed and ecologically unstable conditions with respect to the Hauptlithodendronkalk of the NCA (Unit C), likely due to the more landward and restricted palaeogeographic position with respect to the NCA (Tomašovych 2004). The absence of extensive coral patch reefs in the Western Carpathians may reflect water energy, salinity and turbidity unsuitable for corals (Tomašovych 2004).
A striking correspondence seems to exist between the study area and the Lombardy Basin in the Southern Alps (N Italy), where the peritidal early-dolomitized platform interior with fault-controlled intraplatform basins of the Dolomia Principale (Norian; Berra and Jadoul 1996; Berra et al. 2010) is followed by subtidal claystone (Riva di Solto Shales, upper Norian), shallowing-up into cyclic mixed carbonate–siliciclastic ramp (Zu Limestone, Rhaetian; Jadoul et al. 2004). The Riva di Solto Shales and Zu Limestone (together up to 1000 m thick) are time-equivalent to the NCA Kössen Fm. and Upper Rhaetian Limestone, with similar stratigraphic evolution and palaeoenvironmental affinities (Unit B, C, D), although the greater thickness reflects higher subsidence rate in the Lombardy Basin. The Zu Limestone was divided in three members, from base to top, Zu1, Zu2 and Zu3 (Masetti et al. 1989; Lakew 1990; Jadoul et al. 1994, 2004; Galli et al. 2005, 2007; Rigo et al. 2009). Zu1 Member is a cyclical succession of claystone, marlstone and micritic limestone with bivalves. Zu2 Member is a massive limestone unit, up to 25 m thick and laterally continuous for 160 km, consisting of coral patch reefs, bioturbated wackestone and ooidal packstone/grainstone, locally rich in megalodontid bivalves. Zu3 Member is composed of marlstone, marly and micritic limestone organised in asymmetric shallowing-upward cycles, with basal marlstone (10 m thick) passing to peloidal ooidal grainstone or packstone and bioturbated wackestone/packstone with Triasina hantkeni, corals, calcisponges, bryozoans, megalodontid bivalves and dasyclad algae (Lakew 1990; Jadoul et al. 1994; Galli et al. 2007). The top of Zu3 is affected by meteoric diagenesis due to subaerial exposure (Lakew 1990; Jadoul et al. 2005). The Rhaetian Zu2 and Zu3 members match with Unit C and D distinguished in this study, in terms of lithofacies types, benthic foraminifera association and cyclic patterns. The subaerial exposure identified at the top of Unit D can be correlated with the subaerial exposure at the top of Zu3. The Zu3 Member is overlain by the Malanotte Formation (from latest Rhaetian to early Hettangian; Bottini et al. 2016) consisting of bedded marly limestone, with sparse claystone beds with quartz grains and bioturbated bioclastic limestone with thin-shelled bivalves and sponge spicules passing to grainstone–packstone with micritised ooids (Galli et al. 2005, 2007). The Malanotte Fm. resembles the strata in the lower Unit E dominated by peloidal packstone with siliceous sponge spicules (F23). Biostratigraphic and magnetostratigraphic studies located the Triassic/Jurassic boundary in the lower part of the Malanotte Fm. (Galli et al. 2007; Muttoni et al. 2010; Bottini et al. 2016; Zaffani et al. 2018). The overlying Hettangian Albenza Fm. consists of cross-bedded ooidal grainstone passing upward to peloidal packstone and bio-intraclastic grainstone (Galli et al. 2005, 2007; Jadoul and Galli 2008). The Albenza Fm. lithofacies are similar to the upper Unit E dominated by coated grain ooidal grainstone (F22). In western Lombardy, Jadoul et al. (2005) described a shallow-water subtidal to intertidal succession (35 m thick, Alpe Perino Limestone; Hettangian–lower Sinemurian) overlying the Albenza Fm. ooidal grainstone on structural highs before the Sinemurian deepening and pelagic limestone deposition (Moltrasio Fm.). Jadoul et al. (2005) reported lower Jurassic shallow-water carbonates developed on structural highs in the western (Varese High) and eastern (Botticino High) Lombardy Basin with lithofacies types (Alpe Perino Limestone, Corna Fm.) that are similar to lithofacies F26, F27 and F28 (Unit F) from this study.
The similarities between the Lombardy Basin and the NCA were already highlighted by Galli et al. (2007) who linked the Zu Limestone, Malanotte Fm. and Albenza Fm. succession to the Vorarlberg region of the western NCA, where the Kössen Fm. is overlain, above an erosional unconformity, by the marlstone and marly limestone of the Schattwald Beds and Lorüns oolite (McRoberts et al. 1997), as it is proposed for Unit E in this study.
The Triassic–Jurassic boundary in shallow-water carbonates from the eastern NCA
Integrating the results from this study with the regional reconstructions (Gawlick et al. 2009; Krystyn et al. 2005) and the comparison with other paleogeographic domains, a revised depositional reconstruction of the study area is proposed in Fig. 16. Unit D subtidal cyclothems with claystone, mapped as Kössen Fm. in the Kreuss (2014) geological map, is interpreted as time-equivalent to the Eiberg Mb. and the Upper Rhaetian Limestone at the southern margin of the Eiberg Basin. In fact, in the Steinplatte area the top of the Upper Rhaetian Limestone is affected by a subaerial exposure (Kaufmann 2009), similarly to the exposure at the top of Unit D. The overlying Unit E coated grain ooidal grainstone, mapped as Upper Rhaetian Limestone by Kreuss (2014), is interpreted as transitional to lower Jurassic, based on the lack of Rhaetian biostratigraphic markers as well as the lack of corals and diverse skeletal biota that characterise Units C and D before the end-Triassic extinction. This hypothesis is supported by the similarity of Unit E lithofacies (F19, F22) with aggregate grain and ooidal grainstone deposits dated to the Hettangian–Sinemurian described in the Lombardy Basin (Albenza Fm., Southern Alps, N Italy; Galli et al. 2005, 2007; Bottini et al. 2016), Trento Platform (Calcari Grigi Group, Southern Alps, NE Italy; Borsato et al. 1994; Preto et al. 2017; Masetti et al. 2017; Vulpius and Kiessling 2018; Julian Alps, Slovenia; Ciarapica and Passeri 1990), western Dinarides (Croatia; Buckovic et al. 2001), Transdanubian Range (Kardosrét Limestone, Hungary; Vörös and Galácz 1998), Western Carpathians (Tatra Mts., Hronicum domain, Poland; Rychliński et al. 2018) and Apennines (Central and Southern Italy, Calcare Massiccio; Ciarapica 2007), as well as in the western NCA (Löruns, Austria; McRoberts et al. 1997; Felber et al. 2015). The abundance of ooids in Unit E and of microbialites in Unit F might reflect the effect of the biotic crisis related to the end-Triassic extinction as observed elsewhere in the aftermath of extinction events (e.g. Permian–Triassic; Li et al. 2015; end-Triassic, United Arab Emirates; Ge et al. 2019). Unit G chert layers, the abundance of detrital quartz and the sedimentological features of lithofacies F32 correspond to the Kalksburg Fm. (Hettangian–Sinemurian; cf. Gawlick et al. 2009).
Controlling factors on the stratigraphy of Western Tethys
The similarities, in terms of lithofacies associations and stacking pattern, among coeval successions deposited in different palaeogeographic domains (i.e. eastern and western NCA, Central Austroalpine, Western Carpathians, Transdanubian Range, Dinarides, Southern Alps) reveal that the Norian to Jurassic stratigraphic evolution of Western Tethys was controlled by the interplay of environmental, climatic and tectonic regimes producing similar sedimentological responses at regional scales. These factors can be identified influencing the Western Tethys depositional settings: (a) climate change controlling the intensity of weathering triggering a major input of clay and the demise of the widespread early dolomitization, suggesting a transition towards humid conditions in the latest Norian–Rhaetian (Berra et al. 2010), (b) Rhaetian favourable conditions for the expansion of coral boundstone; (c) biocalcification crisis of the end-Triassic extinction event (McRoberts et al. 2012), (d) an end-Triassic sea-level fall followed by rapid rise (Hallam and Wignall 1999; Pálfy and Zajzon 2012), (e) early Jurassic recovery of carbonate production with ooidal grainstone and microbialites; (f) early Jurassic extensional tectonics with development of structural highs where shallow-water carbonates accumulated before the drowning represented by red crinoidal-rich and hemipelagic limestone (Bernoulli 1964; Eberli 1988; Jadoul et al. 2005; Gawlick et al. 2009; Gawlick and Missoni 2019).
This study performed in the eastern NCA on the upper Norian–Rhaetian to Jurassic mixed carbonate–siliciclastic sedimentary units and the comparison with coeval successions demonstrate that regional and global processes drove the stratigraphic evolution of Western Tethys, from the Austroalpine to the Southern Alps to Western Carpathians, as recorded by the strikingly similar lithofacies character and stratigraphic evolution.
Conclusions
The sedimentological investigation of the nearly 350 m thick, shallow-water Rhaetian–Lower Jurassic mixed carbonate–siliciclastic succession of the Stumpfmauer area in the eastern NCA allowed identifying 32 lithofacies, grouped in seven sedimentary units (from A to G), recording the stratigraphic evolution of shelf depositional environments, located north of the upper Rhaetian Eiberg Basin.
This shallow-water succession comprises: the Hochalm Mb. of the Kössen Fm. (Unit A peritidal cyclothems, Unit B claystone/marlstone with fossiliferous beds) and the regional coral limestone marker bed Hauptlithodendronkalk (Unit C coral boundstone to floatstone), the Upper Rhaetian Limestone time-equivalent to the Eiberg Mb. of the Kössen Fm. (Unit D subtidal cyclothems with claystone), shallow-water carbonate strata transitional to the Lower Jurassic up to the Kalksburg Fm. (Unit E ooidal coated grain peloidal grainstone with basal transgressive lag, Unit F bivalve-rich, microbialite and oncoidal lithofacies, Unit G cross-laminated coated grain peloidal grainstone with quartz and chert).
Differently from the published geological maps, in this study Units E and F are attributed to a lower Jurassic shallow-water depositional system post-dating a laterally extensive subaerial exposure surface at the top of Unit D, based on: (a) the sharp change in skeletal biota with the disappearance of corals and Rhaetian foraminifera (e.g. Triasina hantkeni) common in the underlying Unit D; (b) the onset of abundant detrital quartz, siliceous sponge spicules and chert, and (c) the similarities with Lower Jurassic ooidal grainstone lithofacies and stratigraphic evolution in the western NCA, Southern Alps, Western Carpathians, Transdanubian Range and Dinarides. Unit E ooidal grainstone and Unit F microbial boundstone are interpreted to reflect the biotic crisis in the aftermath of the end-Triassic extinction.
The evolution of the studied succession demonstrates the influence of climate, environmental changes and extensional tectonics (linked to the opening of the Penninic Ocean) on the western Tethys carbonate shelf, driving similar responses in different palaeogeographic domains: a shift towards humid conditions required to explain the latest Norian–early Rhaetian clay input (Units A and B), the Rhaetian expansion of phaceloid coral boundstone (Unit C), a major sea-level fall (top of Unit D) followed by transgression and change in skeletal biota marking the end-Triassic extinction and transition to early Jurassic (Unit E), the aftermath of the biotic crisis manifested by abundance of ooidal grainstone and microbialites (Units E and F), lower Jurassic shallow-water carbonate strata on structural highs (Units E, F and G) and gradual deepening upward due to extensional tectonics.
Data availability
Data supporting this study are reported in this manuscript and in the Online Supplementary Information. Additional data will be made available upon request to the corresponding author.
References
Bernecker M (2005) Late Triassic reefs from the Northwest and South Tethys: distribution, setting, and biotic composition. Facies 51:442–453. https://doi.org/10.1007/s10347-005-0067-4
Bernecker M, Weidlich O, Flügel E (1999) Response of Triassic reef coral communities to sea-level fluctuations, storms and sedimentation: evidence from a spectacular outcrop (Adnet, Austria). Facies 40:229–279. https://doi.org/10.1007/BF02537476
Bernoulli D (1964) Zur Geologie des Monte Generoso. Beitr Geol Karte Schweiz 118:1–134
Bernoulli D, Jenkyns HC (1974) Alpine Mediterranean and central Atlantic Mesozoic facies in relation to the early evolution of the Tethys. Special Publication Soc Econ Paleontol Mineral 19:129–160. https://doi.org/10.1007/978-1-4612-3494-4_5
Berra F, Cirilli S (1997) Palaeoenvironmental interpretation of the Late Triassic Fraele Formation (Ortles Nappe, Austroalpine domain, Lombardy). Riv Ital Paleontol Stratigr 103:53–70
Berra F, Jadoul F (1996) Norian serpulid and microbial bioconstructions: Implication for the platform evolution in the Lombardy Basin (Southern Alps, Italy). Facies 35:143–162
Berra F, Jadoul F, Anelli A (2010) Environmental control on the end of the Dolomia Principale/Hauptdolomit depositional system in the central Alps: coupling sea-level and climate changes. Palaeogeogr Palaeoclimatol Palaeoecol 290:138–150. https://doi.org/10.1016/j.palaeo.2009.06.037
Böhm F, Dommergues JL, Meister C (1995) Breccias of the Adnet Formation: indicators of a Mid-Liassic event in the Northern Calcareous Alps (Salzburg/Austria). Geologische Rundschau Berlin Heidelberg 84:272–286
Borsato A, Frisia S, Sartorio D (1994) Late Triassic-Early Liassic stratigraphic and diagenetic evolution of the margin between the Trento platform and the Lombardy Basin in the Brenta Dolomites (Italy). Acta Geol 69:5–35
Bottini C, Jadoul F, Rigo M, Zaffani M, Artoni C, Erba E (2016) Calcareous nannofossils at the Triassic/Jurassic boundary: stratigraphic and paleoceanographic characterization. Riv It Paleontol Strat 122:141–164. https://doi.org/10.13130/2039-4942/7726
Buckovic D, Jelaska V, Tesovic BC (2001) Facies variability in Lower Liassic carbonate successions of the western Dinarides (Croatia). Facies 44:151–162
Caggiati M, Gianolla P, Breda A, Celarc B, Preto N (2018) The start-up of the Dolomia Principale/Hauptdolomit carbonate platform (Upper Triassic) in the eastern Southern Alps. Sedimentology 65:1097–1131
Ciarapica G (2007) Regional and global changes around the Triassic-Jurassic boundary reflected in the late Norian-Hettangian history of the Apennine basins. Palaeogeogr Palaeoclimatol Palaeoecol 244:34–51
Ciarapica G, Passeri L (1990) The Dachstein limestone of the Mt. Canin (Julian Alps) and its paleogeographic meaning. Bollettino Della Società Geologica Italiana 109:239–247
Clémence ME, Gardin S, Bartolini A, Paris G, Beaumont V, Guex J (2010) Bentho-planktonic evidence from the Austrian Alps for a decline in sea-surface carbonate production at the end of the Triassic. Swiss J Geosci 103:293–315. https://doi.org/10.1007/s00015-010-0019-z
Czurda K, Nicklas L (1970) Zur Mikrofazies und Mikrostratigraphie des Hauptdolomites und Plattenkalk-Niveaus der Klostertaler Alpen und des Rhätikon (Nördliche Kalkalpen, Vorarlberg). Univ. Innsbruck, Geolog. Inst.., Innsbruck, pp 165–253
Delecat S, Arp G, Reitner J (2011) Aftermath of the Triassic–Jurassic boundary crisis: spiculite formation on drowned Triassic Steinplatte reef-slope by communities of hexactinellid sponges (northern calcareous Alps, Austria). In: Reitner J. et al. (eds), Advances in Stromatolite Geobiology, Lecture Notes in Earth Sciences 131:355–390. Springer-Verlag, Berlin Heidelberg. https://doi.org/10.1007/978-3-642-10415-2_23
Delecat S, Reitner J (2005) Sponge communities from the Lower Liassic of Adnet (Northern Calcareous Alps, Austria). Facies 51:385–404
Dickson JAD (1966) Carbonate identification and genesis as revealed by staining. J Sediment Res 36:491–505
Eberli GP (1988) The evolution of the southern continental margin of the Jurassic Tethys Ocean as recorded in the Allgäu Formation of the Austroalpine Nappes of Graubünden (Switzerland). Eclogae Geol Helv 81:175–214
Ebli O (1997) Sedimentation und Biofazies an passiven Kontinentalrändern: Lias und Dogger des Mittelabschnittes der Nördlichen Kalkalpen und des frühen Atlantik (DSDP site 547B, offshore Marokko). - Münchner Geowiss. Abh., Reihe A, Geol. Paläont. 32, pp 255, München
Enos P, Samakassou E (1998) Lofer cyclothems revisited (late Triassic, northern Alps, Austria). Facies 38:207–227
Felber R, Weissert HJ, Furrer H, Bontognali TR (2015) The Triassic-Jurassic boundary in the shallow-water marine carbonates from the western Northern Calcareous Alps (Austria). Swiss J Geosci 108:213–224
Fischer AG (1964) The Lofer cyclothems of the Alpine Triassic. In: Merriam, D.F. (ed) Symposium of Cyclic Sedimentation, vol 169. Kansas Geological Survey Bulletin, pp 107–149
Flügel E (1981) Paleoecology and facies of Upper Triassic reefs in the Northern Calcareous Alps. Spec Publ Soc Econ Paleont Miner Tulsa 30:291–359
Flügel E (2002) Triassic reef patterns. In: Kiessling W, Flügel E, Golonka J (eds) Phanerozoic Reef Patterns, SEPM Society for Sedimentary Geology, Special Publication 72, Tulsa, OK, pp 391–463
Flügel E (2004) Microfacies of carbonate rocks. Analysis, interpretation and application. Springer-Verlag, Germany, p 976
Frisch W, Gawlick HJ (2003) 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. Int J Earth Sci 92:712–727. https://doi.org/10.1007/s00531-003-0357-4
Frisch W, Dunkl I, Kuhlemann J (2000) Post-collisional orogen-parallel large-scale extension in the Eastern Alps. Tectonophysics 327:239–265. https://doi.org/10.1016/S0040-1951(00)00204-3
Fruth I, Scherreiks R (1982) Hauptdolomit (Norian)—stratigraphy, paleogeography and diagenesis. Sed Geol 32:195–231
Fruth I, Scherreiks R (1984) Hauptdolomit - Sedimentary and Paleogeographic Models (Norian, Northern Calcareous Alps). Geol Rundsch 73:305–319
Furrer H (1981) Stratigraphie und Facies der trias/Jura-grenzschichten in den oberostalpinen Decken Graubündens. Ph.D. Thesis, Geol. Inst. Univ. Zürich, 111 pp, Zürich
Galli MT, Jadoul F, Bernasconi SM, Weissert H (2005) Anomalies in global carbon cycling and extinction at the Triassic/Jurassic boundary: evidence from a marine C-isotope record. Palaeogeogr Palaeoclimatol Palaeoecol 216:203–214. https://doi.org/10.1016/j.palaeo.2004.11.009
Galli MT, Jadoul F, Bernasconi SM, Cirilli S, Weissert H (2007) Stratigraphy and paleoenvironmental analysis of the Triassic-Jurassic transition in the western Southern Alps (Northern Italy). Palaeogeogr Palaeoclimatol Palaeoecol 244:52–70. https://doi.org/10.1016/j.palaeo.2006.06.023
Gawlick HJ, Böhm F (2000) Sequence and isotope stratigraphy of Late Triassic distal periplatform limestones from the northern Calcareous Alps (Kälberstein Quarry, Berchtesgaden Hallstatt Zone). Int J Earth Sci 89:108–129
Gawlick HJ, Missoni S (2019) Middle-Late Jurassic sedimentary mélange formation related to ophiolite obduction in the Alpine-Carpathian-Dinaridic Mountain Range. Gondwana Res 74:144–172
Gawlick HJ, Frisch W, Vecsei A, Steiger T, Böhm F (1999) The change from rifting to thrusting in the Northern Calcareous Alps as recorded in Jurassic sediments. Geol Rundsch 87:644–657
Gawlick HJ, Frisch W, Hoxha L, Dumitrica P, Krystyn L, Lein R, Missoni S, Schlagintweit F (2008) Mirdita Zone ophiolites and associated sediments in Albania reveal Neotethys Ocean origin. Int J Earth Sci 97:865–881
Gawlick HJ, Missoni S, Schlagintweit F, Suzuki H, Frisch W, Krystyn L, Blau J, Lein R (2009) Jurassic Tectonostratigraphy of the Austroalpine domain. J Alpine Geol 50:1–152
Ge Y, Al-Suwaidi AH, Shi M, Li Q, Morad S, Steuber T (2019) Short-term variation of ooid mineralogy in the Triassic-Jurassic boundary interval and its environmental implications: evidence from the equatorial Ghalilah Formation, United Arab Emirates. Global Planet Change 182:103006
Golebiowski R (1989) Stratigraphie und Biofazies der Kössener Formation (Obertrias, Nördliche Kalkalpen). Ph.D. Thesis (unpubl.) University of Vienna
Golebiowski R (1990) The alpine Kössen Formation, a key for European topmost Triassic correlations. Albertiana 8:25–35
Golebiowski R (1991) Becken und Riffe der alpinen Obertrias: Lithostratigraphie und Biofazies der Kössener Formation. In: Nagel D, Rabeder G (eds) Exkursionen im Jungpaläozoikum und Mesozoikum Österreich. Österreichische Paläontologische Gesellschaft, Vienna, pp 79–119
Guex J, Bartolini A, Atudorei V, Taylor D (2004) High resolution ammonite and carbon isotope stratigraphy across the Triassic-Jurassic boundary at New York Canyon (Nevada). Earth Planet Sci Lett 225:29–41. https://doi.org/10.1016/j.epsl.2004.06.006
Haas J, Kovács S, Krystyn L, Lein R (1995) Significance of Late Permian-Triassic facies zones in terrane reconstructions in the Alpine-North Pannonian domain. Tectonophysics 242:19–40. https://doi.org/10.1016/0040-1951(94)00157-5
Haas J, Budai T, Hips K, Czuppon G, Győri O, Horváth A, Héja G (2022) Dolomitization of Late Norian carbonate deposits of restricted basin facies in the Keszthely Mts., Transdanubian Range, Hungary. Int J Earth Sci 111:245–268
Hallam A (2002) How catastrophic was the end-Triassic mass extinction? Lethaia 35:147–157. https://doi.org/10.1111/j.1502-3931.2002.tb00075.x
Hallam A, Wignall PB (1999) Mass extinctions and sea-level changes. Earth Sci Rev 48(4):217–250. https://doi.org/10.1016/S0012-8252(99)00055-0
Héja G, Kövér S, Csillag G, Németh A, Fodor L (2018) Evidences for pre-orogenic passive-margin extension in a Cretaceous fold-and-thrust belt on the basis of combined seismic and field data (western Transdanubian Range, Hungary). Int J Earth Sci 107:2955–2973
Hesselbo SP, Robinson SA, Surlyk F, Piasecki S (2002) Terrestrial and marine extinction at the Triassic-Jurassic boundary synchronized with major carbon-cycle perturbation:a link to initiation of massive volcanism? Geology 30:251–254. https://doi.org/10.1130/0091-7613(2002)030%3c0251:TAMEAT%3e2.0.CO;2
Hillebrandt AV, Urlichs M (2008) Foraminifera and ostracoda from the Northern Calcareous Alps and the end-Triassic biotic crisis. Berichte Geol. B-A 76:70–72
Hillebrandt AV, Krystyn L, Kürschner WM, Bonis NR, Ruhl M, Richoz S, Shobben MAN, Urlichs M, Bown PR, Kment K, McRoberts CA, Simms M, Tomãsovych A (2013) The global stratotype sections and point (GSSP) for the base of the Jurassic System at Kuhjoch (Karwendel Mountains, Northern Calcareous Alps, Tyrol, Austria). Episodes 36:162–198
Iannace A, Frisia S (1994) Changing dolomitization styles from Norian to Rhaetian in the southern Tethys realm. In Dolomites: A Volume in Honour of Dolomieu, vol. 21. Blackwell Publishing Ltd., Oxford, pp 75–89
Jadoul F, Galli MT (2008) The Hettangian shallow water carbonates after the Triassic/Jurassic biocalcification crisis: the Albenza formation in the western Southern Alps. Riv Ital Paleontol Stratigr 114:453–470. https://doi.org/10.13130/2039-4942/5911
Jadoul F, Galli MT, Calabrese L, Gnaccolini M (2005) Stratigraphy of Rhaetian to Lower Sinemurian carbonate platforms in western Lombardy (Southern Alps, Italy): paleogeographic implications. Riv Ital Paleontol Stratigr 111:285–303
Jadoul F, Masetti D, Cirilli S, Berra F, Claps M, Frisia S (1994) Norian–Rhaetian stratigraphy and paleogeographic evolution of the Lombardy Basin (Bergamasc Alps): Excursion B1, 15th IAS Regional Meeting: 5–38
Jadoul F, Galli MT, Berra F, Cirilli S, Ronchi P, Paganoni A (2004) The Late Triassic-Early Jurassic of the Lombardy Basin: stratigraphy, palaeogeography and palaeontology. International Geological Congress. Field guide book excursion P86
Kaufmann B (2009) The Steinplatte complex (Late Triassic, Northern Calcareous Alps, Austria)—subsidence-controlled development of a carbonate-platform-to-intrashelf basin-transition. Acta Geol Pol 59:341–357
Köppen A, Carter A (2000) Constraints on provenance of the central European Triassic using detrital zircon fission track data. Palaeogeogr Palaeoclimatol Palaeoecol 161:193–204
Kozur H (1991) The evolution of the Meliata - Hallstatt Ocean and its significance for the early evolution of the Eastern Alps and Western Carpathians. Palaeogeogr Palaeoclimatol Palaeoecol 87:109–135. https://doi.org/10.1016/0031-0182(91)90132-B
Kreuss (2014) GEOFAST Zusammenstellung ausgewählter Archivunterlagen der Geologischen Bundesanstalt 1:50.000 - 100 Hieflau: GBA 2014, Ausgabe 2014/09, Wien
Krystyn L, Böhm F, Kürschner W, Delecat S, Pálfy J, Ozsvárt P (2005) The Triassic–Jurassic boundary in the Northern Calcareous Alps. 5th field workshop of IGCP 458:A1–A37
Kuss J (1983) Faziesentwicklung in proximalen Intraplattform-Becken: Sedimentation, Palökologie und Geochemie der Kössener Schichten (Ober-Trias, Nördliche Kalkalpen). Facies 9:61–171
Lakew T (1990) Microfacies and cyclic sedimentation of the Upper Triassic (Rhaetian) Calcare di Zu (southern Alps). Facies 22:187–231. https://doi.org/10.1007/BF02536952
Li F, Yan J, Chen ZQ, Ogg JG, Tian L, Korngreen D, Liu K, Ma Z, Woods AD (2015) Global oolite deposits across the Permian-Triassic boundary: a synthesis and implications for palaeoceanography immediately after the end-Permian biocrisis. Earth Sci Rev 149:163–180
Manatschal G, Bernoulli D (1999) Architecture and tectonic evolution of non-volcanic margins: present-day Galicia and ancient Adria. Tectonics 18:1099–1199. https://doi.org/10.1029/1999TC900041
Mandl GW (1999) Field trip guide – Dachstein Hallstatt – Salzkammergut. Berichte Geol B-A 49:1–113
Mandl GW (2000) The Alpine sector of the Tethyan shelf–examples of Triassic to Jurassic sedimentation and deformation from the Northern Calcareous Alps. Mitteilungen Der Österreichischen Geologischen Gesellschaft 92:61–77
Marzoli A, Bertrand H, Knight KB, Cirilli S, Buratti N, Vérati C, Nomade S, Renne PR, Youbi N, Martini R, Allenbach K, Neuwerth R, Rapaille C, Zaninetti L, Bellieni G (2004) Synchrony of the Central Atlantic magmatic province and the Triassic-Jurassic boundary climatic and biotic crisis. Geology 32:973–976. https://doi.org/10.1130/G20652.1
Masetti D, Stefani M, Burchell M (1989) Asymmetric cycles in the Rhaetic facies of Southern Alps: platform-basin interactions governed by eustatic and climatic oscillations. Riv Ital Paleontol Stratigr 94:401–424
Masetti D, Figus B, Jenkyns HC, Barattolo F, Mattioli E, Posenato R (2017) Carbon-isotope anomalies and demise of carbonate platforms in the Sinemurian (Early Jurassic) of the Tethyan region: evidence from the Southern Alps (Northern Italy). Geol Mag 154:625–650
Matzner C (1986) Die Zlambach-Schichten (Rhät) in den Nördlichen Kalkalpen: Eine Plattform-Hang-Beckenentwicklung mit allochthoner Karbonatsedimentation. Facies 14:1–103
Maurer F, Rettori R, Martini R (2008) Triassic stratigraphy, facies and evolution of the Arabian shelf in the northern United Arab Emirates. Int J Earth Sci 97:765–784
McRoberts CA, Furrer H, Jones DS (1997) Palaeoenvironmental interpretation of a Triassic-Jurassic boundary section from Western Austria based on palaeoecological and geochemical data. Palaeogeogr Palaeoclimatol Palaeoecol 136:79–95
McRoberts CA, Krystyn L, Hautmann M (2012) Macrofaunal response to the end-Triassic mass extinction in the West-Tethyan Kössen Basin, Austria. Palaios 27:607–616. https://doi.org/10.2110/palo.2012.p12-043r
Mette W, Elsler A, Korte C (2012) Palaeoenvironmental changes in the Late Triassic (Rhaetian) of the Northern Calcareous Alps: clues from stable isotopes and microfossils. Palaeogeogr Palaeoclimatol Palaeoecol 350:62–72. https://doi.org/10.1016/j.palaeo.2012.06.013
Mette W, Thibault N, Krystyn L, Korte C, Clémence MR, Rizzi M, Ullmann CV (2016) Field trip 11 Rhaetian (Late Triassic) biotic and carbon isotope events and intraplatform basin development in the Northern Calcareous Alps, Tyrol, Austria. Geol Alp 13:233–256
Missoni S, Gawlick HJ, Suzuki H, Diersche V (2005) Die paläogeographische Stellung des Watzmann Blockes in den Berchtesgadener Kalkalpen-Neuergebnisse auf der Basis der Analyse der Trias-und Jura-Entwicklung. J Alpine Geol 47:169–209
Muttoni G, Kent DV, Jadoul F, Olsen PE, Rigo M, Galli MT, Nicora A (2010) Rhaetian magneto-biostratigraphy from the Southern Alps (Italy): constraints on Triassic chronology. Palaeogeogr Palaeoclimatol Palaeoecol 285:1–16. https://doi.org/10.1016/j.palaeo.2009.10.014
Pàlfy J, Demény A, Haas J, Hetényi M, Orchard MJ, Veti I (2001) Carbon isotope anomaly and other geochemical changes at the Triassic-Jurassic boundary from a marine section in Hungary. Geology 29:1047–1050
Pálfy J, Zajzon N (2012) Environmental changes across the Triassic-Jurassic boundary and coeval volcanism inferred from elemental geochemistry and mineralogy in the Kendlbachgraben section (Northern Calcareous Alps, Austria). Earth Planet Sci Lett 335:121–134. https://doi.org/10.1016/j.epsl.2012.01.039
Piller WE (1981) The Steinplatte reef complex, part of an Upper Triassic carbonate platform near Salzburg, Austria. In: Toomey DF (ed) European fossil reef models. Geological Society of America SEPM, pp 261–290
Pomar L, Hallock P (2008) Carbonate factories: a conundrum in sedimentary geology. Earth Sci Rev 87:134–169
Preto N, Breda A, Dal Corso J, Franceschi M, Rocca F, Spada C, Roghi G (2017) The Loppio Oolitic Limestone (Early Jurassic, Southern Alps): a prograding oolitic body with high original porosity originated by a carbonate platform crisis and recovery. Mar Pet Geol 79:394–411
Ratschbacher L, Frisch W, Neubauer F, Schmid SM, Neugebauer J (1989) Extension in compressional orogenic belts: the eastern Alps. Geology 17:404–407. https://doi.org/10.1130/0091-7613(1989)017%3c0404:EICOBT%3e2.3.CO;2
Ratschbacher L, Frisch W, Linzer HG, Merle O (1991) Lateral extrusion in the Eastern Alps, part 2: structural analysis. Tectonics 10:257–271. https://doi.org/10.1029/90TC02623
Richoz S, Krystyn L, Hillebrandt AV, Martindale R (2012) End-Triassic crisis events recorded in platform and basin of the Austrian Alps. The Triassic/Jurassic and Norian/Rhaetian GSSPs. J Alpine Geol 54:323–377
Rigo M, Galli MT, Jadoul F (2009) Late Triassic biostratigraphic constraints in the Imagna Valley (western Bergamasc Alps, Italy). Albertiana 37:39–42
Rizzi M, Thibault N, Ullmann CV, Ruhl M, Olsen TK, Moreau J, Clémence ME, Mette W, Korte C (2020) Sedimentology and carbon isotope stratigraphy of the Rhaetian Hochalm section (Late Triassic, Austria). Glob Planet Change 191:103210. https://doi.org/10.1016/j.gloplacha.2020.103210
Ruhl M, Kürschner WM (2011) Multiple phases of carbon cycle disturbance from large igneous province formation at the Triassic-Jurassic transition. Geology 39:431–434. https://doi.org/10.1130/G31680.1
Ruhl M, Kürschner WM, Krystyn L (2009) Triassic-Jurassic organic carbon isotope stratigraphy of key sections in the western Tethys realm (Austria). Earth Planet Sci Lett 281:169–187. https://doi.org/10.1016/j.epsl.2009.02.020
Rychliński T, Uchman A, Gaździcki A (2018) Lower Jurassic Bahamian-type facies in the Choč Nappe (Tatra Mts, West Carpathians, Poland) influenced by paleocirculation in the Western Tethys. Facies 64:1–17
Samankassou E, Enos P (2019) Lateral facies variations in the Triassic Dachstein platform: a challenge for cyclostratigraphy. Deposit Record 5:469–485. https://doi.org/10.1002/dep2.80
Satterley AK (1996a) Cyclic carbonate sedimentation in the Upper Triassic Dachstein Limestone, Austria; the role of patterns of sediment supply and tectonics in a platform-reef-basin system. J Sediment Res 66:307–323
Satterley AK (1996b) The interpretation of cyclic successions of the Middle and Upper Triassic of the Northern and Southern Alps. Earth Sci Rev 40:181–207. https://doi.org/10.1016/0012-8252(95)00063-1
Satterley AK, Brandner R (1995) The genesis of Lofer cycles of the Dachstein Limestone, Northern Calcareous Alps, Austria. Geol Rundsch 84:287–292
Satterley AK, Marshall JD, Fairchild IJ (1994) Diagenesis of an Upper Triassic reef complex, Wilde Kirche, Northern Calcareous Alps, Austria. Sedimentology 41:935–950
Schäfer P (1979) Fazielle Entwicklung und palökologische Zonierung zweier obertriadischer Riff-strukturen in den Nördlichen Kalkalpen (“Oberrhät”-riffkalke, Salzburg). Facies 1:3–245
Schlager W (2003) Benthic carbonate factories of the Phanerozoic. Int J Earth Sci 92:445–464
Schlager W, Schöllnberger W (1974) Das Prinzip stratigraphischer Wenden in der Schichtfolge der Nördlichen Kalkalpen. Mitt Geol Ges Wien 66:165–193
Schmid SM, Fügenschuh B, Kissling E, Schuster R (2004) Tectonic map and overall architecture of the Alpine orogen. Eclogae Geol Helv 97:93–117. https://doi.org/10.1007/s00015-004-1113-x
Schnabel W, Fuchs G, Matura A, Bryda G, Egger J, Krenmayer HG, Scharbert S (2002) Geologische Karte von Niederösterreich 1:200.000 mit Legende und Kurzerläuterung: 3B1, Vienna, Geol.B.A.2 sheets
Schott M (1983) Sedimentation und Diagenese einer absinkenden Karbonatplattform: Rhät und Lias des Brünnstein-Auerbach-Gebietes, Bayerische Kalkalpen. Facies 9:1–59
Schott M (1984) Mikrofaziell-multivariate Analyse einer rhäto-liassischen Karbonatplattform in den Nördlichen Kalkalpen. Facies 11:229–279
Sepkoski JJ (1996) Patterns of Phanerozoic extinction: a perspective from global data bases. In: Walliser OH (ed) Global biological events and event stratigraphy in the Phanerozoic International Interdisciplinary Cooperation in the IGCP-Project 216. Springer, Berlin, pp 35–51
Stanton RJ, Flügel E (1989) Problems with reef models: the late Triassic Steinplatte “reef” (northern Alps, Salzburg/Tyrol, Austria). Facies 20:1–138
Stanton RJ Jr, Flügel E (1995) An accretionary distally steepened ramp at an intrashelf basin margin: an alternative explanation for the Upper Triassic Steinplatte “reef” (Northern Calcareous Alps, Austria). Sed Geol 95:269–286
Steiner P (1965a) Die Eingliederung der Weyerer Bögen und der Gr. Reiflinger Scholle in den Faltenbau des Lunzer-Reichraminger Deckensystems. Mitt. Ges. Geol. Bergbaustudenten, Band, Wien: 14–15
Steiner P (1965b) Zur Geologie der Südwestlichen Lunzer Decke. PhD thesis, University of Vienna: 162 pp
Steiner P (1967) Geologische Studien im Grenzbereich der mittleren und östlichen Kalkalpen (Österreich). Mitt. Ges. Geol. Bergbaustudenten Band, Wien, 18
Strauss P, Granado P, Muñoz JA (2020) Subsidence analysis of salt tectonics-driven carbonate minibasins (Northern Calcareous Alps, Austria). Basin Res 33:968–990. https://doi.org/10.1111/bre.12500
Suess E, Mojsisovics EV (1868) Studien über die Trias- und Jurabildungen in den östlichen Alpen. Die Gebirgsgruppe des Osterhornes. Jahrbuch Des Kaiserlich-Königlichen Geologischen Reichsanstalt 18:168–200
Tollmann A (1965) Geologie der Kalkvoralpen im Ötscherland als Beispiel alpiner Deckentektonik. Mitteilungen Der Geologischen Gesellschaft in Wien 58:103–207
Tollmann A (1976) Analyse des klassischen nordalpinen Mesozoikums. Stratigraphie, Fauna und Fazies der Nördlichen Kalkalpen: pp 1–580, (Deuticke) Wien
Tollmann A (1985) Geologie von Österreich, Band 2: Außerzentralalpiner Anteil: pp 1–710, (Deuticke) Wien
Tomašových A (2004) Microfacies and depositional environment of an Upper Triassic intra-platform carbonate basin: the Fatric Unit of the West Carpathians (Slovakia). Facies 50:77–105. https://doi.org/10.1007/s10347-004-0004-y
Tomašových A (2006) Linking taphonomy to community-level abundance: insights into compositional fidelity of the Upper Triassic shell concentrations (Eastern Alps). Palaeogeogr Palaeoclimatol Palaeoecol 235:355–381
Vlahović I, Tišljar J, Velić I, Matičec D (2005) Evolution of the Adriatic Carbonate Platform: palaeogeography, main events and depositional dynamics. Palaeogeogr Palaeoclimatol Palaeoecol 220:333–360
Vörös A, Galácz A (1998) Jurassic palaeogeography of the Transdanubian Central Range (Hungary). Riv Ital Paleontol Stratigr 104:69–84
Vulpius S, Kiessling W (2018) New constraints on the last aragonite-calcite sea transition from early Jurassic ooids. Facies 64:1–9
Wegerer E, Gawlick H-J (1999) Zur Paläogeographie des gebankten obertriassischen Dachsteinkalkes im Bereich der Staufen-Höllengebirgs-Decke (Nördliche Kalkalpen). Paleogeography of the lagoonal Upper Triassic Dachstein Limestone in the Staufen-Höllengebirgs nappe (Northern Calcareous Alps). Zentralblatt Für Geologie Und Paläontologie, Stuttgart Teil 1:415–434
Wignall PB, Atkinson JW (2020) A two-phase end-Triassic mass extinction. Earth Sci Rev 208:103282
Wright VP, Burgess PM (2005) The carbonate factory continuum, facies mosaics and microfacies: an appraisal of some of the key concepts underpinning carbonate sedimentology. Facies 51:17–23
Zaffani M, Jadoul F, Rigo M (2018) A new Rhaetian δ13Corg record: carbon cycle disturbances, volcanism, End-Triassic mass Extinction (ETE). Earth Sci Rev 178:92–104. https://doi.org/10.1016/j.earscirev.2018.01.004
Zaninetti L, Martini R, Dumont T (1992) Triassic foraminifers from sites 761 and 764, Wombat Plateau, Northwest Australia. In: von Rad U, Haq BU, et al. Proceedings of the Ocean Drilling Program, Scientific Results 122
Acknowledgements
The authors warmly thank OMV Exploration and Production GmbH for funding the project. Curzio Malinverno and Matteo Pegoraro (University of Milan) are thanked for thin sections preparation. Michele Azzarone, Mario De Matteis, Andrea Dimartino, Edoardo Chiarelli are thanked for the help provided during field work and sample analyses. The reviewers Hans Jürgen Gawlick and Felix Schlagintweit are thanked for their useful comments as well as Editor Wolfgang Kiessling.
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Open access funding provided by Università degli Studi di Milano within the CRUI-CARE Agreement. The Rhaetian Carbonate Project was funded by OMV Exploration and Production GmbH to the Department of Earth Sciences of the University of Milan.
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Della Porta, G., Mancini, A. & Berra, F. Facies character and evolution of a mixed carbonate–siliciclastic shelf: Upper Triassic–Lower Jurassic succession in the eastern Northern Calcareous Alps (Stumpfmauer, Austria). Facies 69, 11 (2023). https://doi.org/10.1007/s10347-023-00662-x
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DOI: https://doi.org/10.1007/s10347-023-00662-x