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The “Barmstein Limestones” that are made up of proximal reef debris with allochthonous components (Plöchinger, 1976; Steiger, 1981; Gawlick et al., 2005) represent mass-flows and turbiditic layers in that basinal succession (Oberalm Formation) with components deriving mostly from the adjacent autochthonous Plassen Carbonate Platform, although with the occurrence of older clasts (Schlagintweit & Gawlick, 2007). Reworked Juvavic nappe system = Jurassic Hallstatt Mélange In the area of the Northern Calcareous Alps, the eroded Juvavicum represents the Jurassic accretionary prism of the former Hallstatt facies belt (Frisch & Gawlick, 2003). Remnants of this nappe complex are only present in the Middle to Late Jurassic radiolaritic trenches, where all sedimentary rock types of the Hallstatt facies belt from the transitional area of the Triassic platform to the Meliata facies zone resp. the Neotethys Ocean occur. Meliata facies zone The Meliata facies zone represents the most distal part of the shelf area and the continental slope as well as the transition to the Neotethys Ocean. Rare remnants of these facies belt are described from the eastern (Mandl & Ondrejikova, 1993; Kozur & Mostler, 1992) and central part of the Northern Calcareous Alps (Gawlick, 1993). These remnants occur partly as metamorphosed isolated slides (Florianikogel area) or as breccia components in the Hallstatt Mélange (Gawlick, 1993). The Meliata facies zone should have been the first, which was incorporated in the Neotethys accretionary prism.
Hallstatt limestone facies zone
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• Click on download to get complete and readable text • This is a free of charge document sharing network • First upload your own document, and you get a word document per email • No registration necessary, gratis Swap homeworks and notes at no charge! Gratis scripts for students and pupils! The sediments of the Dürrnberg Formation passes gradually from marly sediments (Hettangian) to cherty limestones (Sinemurian) and later to cherty marls to radiolarites (Pliensbachian) (O´Dogherty & Gawlick, 2008). Toarcian to Aalenian sediments are dark grey marly limestones to grey marls (Missoni & Gawlick, in press). In Middle Jurassic times the Hallstatt facies zone was incorporated into the Neotethys accretionary prism. Resedimented remnants of these early trenches formed in this area occur in the Florianikogel Formation (Piller et al., 2004) and the Sandlingalm Formation (Gawlick et al., 2007a). Zlambach/Pötschen facies zone The Rhaetian marly Zlambach Formation progresses gradually to the Early Jurassic Dürrnberg Formation (Gawlick et al., 2001), made up of marly sediments in its basal part (Hettangian), which gradually progress into cherty limestones (Sinemurian), cherty marls and radiolarites (Pliensbachian) (O´Dogherty & Gawlick, 2008). The Toarcian/Aalenian is represented by dark grey marly limestones and grey marls (Missoni & Gawlick, in press). In Middle Jurassic times the Zlambach/Pötschen facies zone was incorporated into the Neotethys accretionary prism.
Drau Range
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• Click on download to get complete and readable text • This is a free of charge document sharing network • First upload your own document, and you get a word document per email • No registration necessary, gratis Swap homeworks and notes at no charge! Gratis scripts for students and pupils! In the Lienzer Dolomiten Jurassic sediments are only preserved on top of the Oberrhätkalk. In contrast to the Bavaric and the Tirolic units of the Northern Calcareous Alps the shallow-water Oberrhätkalk drowned partly, and was overlain by the Allgäu Formation (partly with breccias = Lavanter breccia) or the Adnet Formation (Fig. 1). Contemporaneously the Lavanter breccia was formed (Hettangian to Sinemurian – Schlager, 1963; Blau & Schmidt, 1988) in contrast to similar but younger breccias in the Tirolic units. This clearly shows that the Lienzer Dolomiten represent a transitional area between the Bavaric units and the Lower Austroalpine, where parts of the Türkenkogel and Tarntaler Breccias started to form in this time (Tollmann, 1977; Häusler, 1988). These breccias were overlain by the Pliensbachian Adnet and the Klaus Formations (Tollmann, 1977; Blau & Schmidt, 1988; Blau, 1994). The overlying sequences are not very well investigated (Tollmann, 1977) the correlation with other Middle to Late Jurassic sequences is poorly constrained (Piller et al., 2004). The radiolarian-rich red cherty limestones may correlate with the cherty sediments of the Ruhpoldinger Radiolarite Group and the red nodular crinoid-rich limestones may correlate with the Late Jurassic Steinmühl Formation.
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• Click on download to get complete and readable text • This is a free of charge document sharing network • First upload your own document, and you get a word document per email • No registration necessary, gratis Swap homeworks and notes at no charge! Gratis scripts for students and pupils! Northern Karavanks The Jurassic sedimentation (Teller, 1888; Tollmann, 1977; Schröder, 1988) started with deposition of red limestones of the Adnet Group which progress into red condensed limestones of the Klaus Formation. The radiolarian-rich red cherty limestone may correlate with the cherty sediments of the Ruhpoldinger Radiolarite Group, and the red nodulare crinoid-rich limestone may correlate with the Late Jurassic Steinmühl Formation. The following calpionellid-rich, reddish-greyish limestones pass into the Early Cretaceous and can be correlated with the Oberalm Formation or Aptychen beds (Suette, 1978; Bauer et al., 1983; Schröder, 1988). Lower Austroalpine to Penninic Units The Jurassic sedimentary successions of the Penninic units represent the distal continuation of the Lower Austroalpine successions towards the newly formed Penninic Ocean, but finer-grained. However, the sedimentary evolution of this unit is more or less the same than that of the Lower Austroalpine passive continental margin. The sedimentary successions are generally highly deformed and metamorphosed, form different nappes and lack mostly determinable fossils (details in Tollmann, 1977). In the Early Jurassic quarzites, arkoses and phyllites (Hochstegenquarzit, Schwarzkopfquarzit) dominate in both windows (Engadin and Tauern window) beside conglomerates (p.p.
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• Click on download to get complete and readable text • This is a free of charge document sharing network • First upload your own document, and you get a word document per email • No registration necessary, gratis Swap homeworks and notes at no charge! Gratis scripts for students and pupils! In Late Jurassic the sedimentation changed from shaly/siliceous sediments to more carbonatic ones. Hochstegen Limestone/Dolomite and Klammkalk in the Tauern and Rechnitz windows (?Oxfordian to Tithonian); Falknis and Sulzfluh Limestone in the Engadin window resp. to the west (?Oxfordian to Tithonian) (Bertle, 1973; Tollmann, 1977; Piller et al., 2004; Höfer & Tichy, 2005). Contemporaneous several breccias were formed (e.g., Schwarzeck Breccia – Tollmann, 1977), indicating new extensional movements, probably related to the opening of the Valais Ocean (Hsü & Briegel, 2001).. Southern Karavanks Koschuta unit Pelagic deposits of Jurassic age are very rare in this unit, but can be found in the western part of Southern Karavanke Mountains (Koschuta and Hahnkogel units according to Krystyn et al., 1994). To some extent they also occur in eastern Sava Folds. Sedimentation took place under deep water conditions. The Jurassic evolution resembles that of the Slovenian Trough. Hettangian to Sinemurian, probably reaching the Toarcian is represented by max. 300 m thick platy limestones with chert nodules, intercalated by thin layers of muddy marlstone (Hahnkogel Formation according to Krystyn et al., 1994). | ||||||||||||
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