Karavanke Alps Hans P. Schönlaub, GeoPark Carnic Alps

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1 Hans P. Schönlaub, GeoPark Carnic Alps Karavanke Alps

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3 Structural correlations between Carnic/Gailtal Alps and Eastern Karavanke Alps Karavanke Alps Carnic/Gailtal Alps Northern Karavanke Alps Foreland?? Northern Karavanke Alps Mesozoic Gailtal Alps Mesozoic ( Drauzug ) Eisenkappel Paleozoic?? Eisenkappel Granite Eisenkappel Crystalline Complex Karavanke Tonalite Seeberg Paleozoic Southern Karavanke Alps Mesozoic Nötsch Granite Gailtal Crystalline Complex Gailtal Tonalite Carnic Alps Paleozoic Carnic Alps Mesozoic

4 Tectonic subdivision of the Eastern Karavanke Alps Quarternary Tertiary Northern Karavanke Alps Mesozoic Eisenkappel Paleozoic (Diabase Unit) Karavanke Granite Karavanke Crystalline Complex Karavanke Tonalite Southern Karavanke Alps Mesozoic Seeberg Paleozoic ( Seeberg Aufbruch ) Fault Periadriatic Line

5 Kamniško Savinjske/ Steiner Alps Triassic Seeberg Palaeozoic Koschuta Triassic Eisenkappel Palaeozoic Granite & Eisenkappel Crystalline Northern Karavanke Alps Triassic P. L. N-S cross section of the eastern Karavanke Alps (after F. Kupsch et al., 1971, modified by F. K. Bauer, 1973 and H. P. Schönlaub). 1: Post-Variscan Permian and Upper Carboniferous, 2: Banded Limestone units, 3: Devonian limestone, 4 : undated volcanics, 5: Hochwipfel Fm., 6: undated shales (Seeberg Shale), 7: Upper Ordovician and Silurian, 8: Upper Ordovician volcanics, 9: Eisenkappel Granite, 10: Pillow lavas of Eisenkappel, 11: Diabase sill of Palaeozoic of Eisenkappel, 12: Werfen Fm., 13: Alpine Muschelkalk Fm., 14: Partnach Fm., 14: Wetterstein Lst. (dolomitic reef debris), 16: Wetterstein Lst. (calcareous reef debris), 17: Wetterstein Lst. (lagoonal facies), 18: Raibl Fm., 19: Rhaetian-Jurassic, 20: Schlern Dolomite, 21: Tertiary, 22: Dachstein Lst. (reef debris facies), 23: Dachstein Lst. (lagoonal facies).

6 Kamniško Savinjske/ Steiner Alps Zimpasserkogel Ebriach Valley Bad Eisenkappel/Železna Kapla

7 Gailtal Crystalline Complex Nötsch Carboniferous Areal view of the Gail Valley with the Carnic Alps (left) and the Gailtal Alps (right)

8 Periadriatic Line Tonalites Gailtal Crystalline Complex Carnic Alps Paleozoic Nötsch Granite Nötsch Carboniferous Gailtal Alps Mesozoic View into the Gail Valley from East showing Carnic Alps in the South and Gailtal Alps to the North

9 Nötsch Gra Gailtal Alps Mesozoic Gailtal Crystalline Complex Geological Map of the Carboniferous of Nötsch

10 Gailtal Alps Mesozoic across Gail Valley (Photo L. Lammerhuber)

11 Summit of Hochobir (2139 m) Northern Karavanke Mesozoic) Eisenkappler Hütte (1555 m) Northern Karavanke Alps Mesozoic

12 Gailtal Crystalline Complex Nötsch Granite Gailtal Crystalline Complex Nötsch Granite and Amphibolite

13 Eisenkappel Granite of Ebriach Valley (above) and Obojnik Creek (below)

14 Eisenkappel Tonalite of Remschenig Valley (above) Eisenkappel Crystalline Complex and hornfels of Remschenig Valley (below)

15 Tuff - Ignimbrite Carnic Alps Karavanke Alps Alps Stratigraphic subdivision of the Carnic and Karavanke Alps Paleozoic (Hubmann et al., 2003, modified from Schönlaub, 1985)

16 Composite section of the ~80 m thick Trögener Group of Upper Ordovician to Upper Devonian age followed by Lower Carboniferous cherts and the Hochwipfel Fm. (after Moshammer, 1989, 1990).

17 Limestones and shales of the 80 m thick Trögen Group dissected into 6 tectonic slices in the Trögen River

18 Eisenkappel Seeberg Pass Geological map of the Eastern Karavanke Alps (compiled by F. K. Bauer, 1981)

19 Seeberg Pass Storschitz Zimpasser Eisenkappel Storschitz Seeberg Pass Zimpasser Eisenkappel

20 Carnic Alps Paleozoic: Kellerwand with Eiskar glacier, Hohe Warte, Biegengebirge (left) and Rauchkofel mountain (right) representing different Devonian limestone environments

21 Sunrise at Kellerwand cliff (Devonian fore-reef), first recognized by Leopold v. Buch 1824

22 Lake Wolayer with mountain Seekopf (2554 m)

23 Seewarte mountain (2595 m), centre of Devonian shallow water deposits with Lake Wolayer

24 Southern cliff of mountain Rauchkofel showing Upper Ordovician to Lower Devonian rock sequences

25 Southern face of Rauchkofel mountain with bedded Rauchkofel Fm. (Lower Devonian -Lochkovian)

26 Meozoic Southern Alps: Gartnerkofel (2195 m) with Middle Triassic Schlern Dolomite

27 Rapold Pasterk Seeberg Pass Geological map of the Seeberg area (compiled by F. K. Bauer, 1981)

28 Rapold Pasterk Seeberg Paleozoic: Distribution of different facies types in the Devonian and Lower Carboniferous of the Seeberg area (after Tessensohn, 1975)

29 Rapold cliff Rapold cliff with upside-down Upper Devonian sequence of reef-debris limestones with fissures and sedimentary gap between basal Famennian and Lower Carboniferous (after Tessensohn, 1975). ~1100 m altitude

30 Base of small Pasterk rock with greyish crinoid-coral bearing limestones of Lochkovian to Pragian age. Containing the historically famous Bronteus Trilobite Fauna of Frech (1887) Big Pasterk cliff Small Pasterk cliff

31 Storschitz Sketch of 250 m thick Devonian reef complex of Storschitz with duplicated backreef and reef facies. 1 = Backreef algal limestone, 2 reef core with corals and stromatoporoids, 3 fault bounded Upper Carboniferous (after Tessensohn, 1975).

32 Mesozoic of Southern Karavanke Alps: Zell Pfarre with Koschuta and Felsentor

33 Sunset in Karavanke Alps (Foto Gailberger) Kamniško Savinjske/Steiner Alps

34 Mesozoic Southern Alps Trögern Gorge: Triassic Schlern Dolomite

35 Information panels Trögen Gorge, Silberbründl

36 The changing face of the Earth

37 The Variscan Orogeny at the boundary between the central and southern Alps

38 Alpine Shelf( Paläogeographie des alpinen Raumes in der Obertrias Development of Alpine Shelf on northern part of Apulian Promontory of the African Plate Upper Triassic palaeogeography: Development of Alpine shelf on northern part of Apulian Spur (Adriatic Promontory).

39 INFO-BOX Age Triassic ( m. y.) General development - increasing production of lime due to rich and diverse organisms (corals, bivalves, brachiopods, ammonoids, porifera, algae etc.) on a shallow marine shelf with development of extended reefs in Middle and Upper Triassic times, lagoons and deep water realms - continuous subsidence over some 50 m.y. resulted in more than 3000 m thick sediment accumulation Palaeogeography - passive continental margin with wide shelf area extending across Apulian Promontory as part of African Plate

40 Middle to Upper Triassic Sketch from the Bohemian Massif towards south with opening Tethys Ocean in Middle to Upper Triassic times

41 INFO-BOX Age Jurassic ( m. y.) General development - Penninic Ocean formed between Africa and Europe - marine sedimentary basin subsided differently due to mobile crust - limestone sedimentation restricted to submarine swells, clayish and marly sediments deposited in deeper parts Palaeogeography - breakup of Pangaea - Atlantic Ocean opened followed by Penninic Ocean ~165 m.y. ago - sedimentation of the later Limestone Alps on the northern part of the Apulian Promontory which was separated from the Helvetic Shelf on the other coast (= European Plate) by the Penninic Ocean - Tethys Ocean started shortening

42 Helvetic Shelf Eastalpine Shelf PALAEOGEOGRAPHY Pangaea broke Paläogeographie up, Penninic Ocean opened. des alpinen Sedimentation Raumes of the later im Limestone Oberjura Alps on the northern part of the Apulian Promontory which is separated from the Helvetic Shelf on the other coast (= European Plate) by the Penninic Ocean. Tethys Ocean started closing Upper Jurassic palaeogeography: Pangaea broke up, Penninic Ocean opened. Sedimentation of the later Limestone Alps on the northern part of the Apulian Spur which was separated from the Helvetic Shelf on the other coast (= European Plate) by the Penninic Ocean. Tethys Ocean started closing.

43 Tethys Ocean is being subducted Upper Jurassic to Lower Cretaceous Sketch from the Bohemian Massif and its cover, the Helvetic Shelf, with opening of the Penninic Ocean, to the Eastalpine Shelf during the Upper Jurassic and Lower Cretaceous

44 Reconstruction of Jurassic life

45 INFO-BOX Age Lower Cretaceous ( m. y.) General development - widening of the Penninic Ocean through production of new oceanic crust, upon which the Bündner Schiefer (schistes lustrès) were deposited - intracontinental subduction within the Austroalpine (Eastalpine) tectonic unit ~135 m.y. ago caused shortening and tectonic subdivision of the Austroalpine into a lower and upper tectonic unit with formation of Austroalpine nappes Palaeogeography - breakup of Pangaea continued - Adriatic Promontory separated from African Plate - Adriatic Microplate started independent drifting - South and Central Atlantic Ocean opened

46 Pillow lava of the Penninic Ocean floor at Idalpe, Tyrol Prasinite of quarry Hinterbichl near Prägraten, Eastern Tyrol reworked and schistosed Jurassic ocean crust

47 INFO-BOX Age Upper Cretaceous ( m. y.) General development - Adriatic Microplate approached Europe - Penninic Ocean started closing - formation of an accretionary wedge (change from passive to active continental margin) - oceanic lithosphere and sediments of Penninic Ocean (flysch-type Bündner Schiefer/ schistes lustrés ) deformed into Penninic nappes - Eo-alpine high p/t metamorphism around 90 m.y affected less distinct the upper tectonic units including limestone areas Palaeogeography - upper nappes formed shallow Austroalpine sedimentary basins subdivided by islands with deposition of Gosau sediments

48 GREENLAND Upper Cretaceous paleogeography: Apulia approached Europe, Penninic Ocean started closing with deposition of thick Flysch deposits which subsequently were transformed into Penninic nappes. Shelf subdivided by islands with Gosau sedimentation. Eo-alpine high p/t metamorphism in deeper crust.

49 Tethys Ocean European Plate Adriatic Plate/Apulia Upper Cretaceous to Eocene Sketch from the Bohemian Massif and its cover, the Helvetic Shelf Flysch trough of Penninic Ocean early Alps in Upper Cretaceous to Eocene time

50 INFO-BOX Age Paleogene ( m. y.) General development - approx. 50 m.y. ago Penninic Ocean was completely closed - southern margin of European Plate was subducted under the Austroalpine orogenic wedge until some 40 m.y. with formation of Helvetic and Subpenninic nappes, respectively - Variscan granites transformed to orthogneisses - temperature-controlled young-alpine metamorphism ( Tauernkristallisation ) m.y. ago slab break-off of lithospheric plate resulted in ascent of hot melts between Austro- and Southalpine (= later Periadriatic Line) which crystallized to granites and tonalites in the crust and volcanoes on the surface, respectively - Adriatic Plate started south-directed thrusting - thickening of crust underneath the central Alps - ~30 m.y. ago adjustment movements starting with slow uplift Palaeogeography - landscape evolution of Austroalpine with hills east of Brenner and low mountains to the west

51 Oligocene paleogeography: Penninic Ocean has completely closed, rise of Austroalpine Unit started and Molasse Basin formed.

52 Periadriatic Line E u r o p e a n P l a t e Oligocene Sketch from the Bohemian Massif across the Molasse Basin to the northward thrusting Alpine nappes during Oligocene times

53 H i l l s i d e mountains Later Tauern Window Reconstruction of the Eastern Alps during the Augenstein-landscape in the late Oligocene when the Northern Limestone Alps were not fully exhumed

54 INFO-BOX Age Paleogene (65 23 m. y.) General development - beginning in the Eocene a foreland basin ( Paratethys ) gradually subsided due to the superimposed load of the overriding Alps on European Plate - until ~15 m.y. filling with debris from the rising Alps and the Bohemian Massif - rich animal and floral heritage Palaeogeography - shallow marine sedimentary molasse basin of Paratehys surrounding the rising Alps

55 INFO-BOX Age Neogene ( m. y.) General development - N-S shortening resulted in indenter of Southern Alps some 20 m.y ago - rapid E-W lithospheric extension and stretching in Pannonian Basin - development of a system of lateral displacements north and south of the Alpine chain - lateral extrusion of Eastern Alps against Pannonian Basin - thinning of central part of Eastern Alps due to normal slip faulting - start of exhumation of Hohe Tauern m.y. ago - internal deformation continued formation of Alpine fissures - formation of intra-alpine Molasse Basins Palaeogeography - since approx. 10 m.y. uplift of Alps with rates of some 5 mm/y, later slowing down to 0.5 mm/y - sedimentation in Molasse Basin continued until 4 m.y. when fresh water lake dried up

56 Indenter Adriatic Plate Sketch of the Alpine-Carpathian area during the middle Miocene: large crustal wedges of the Austroalpine Unit were squeezed out towards the east due to a south-north directed compression (after Peresson & Decker, 1997, modified)

57 African mantle Geological N S section of the Eastern and Southern Alps from Traunsee in Upper Austria to Bohinjsko jezero in Slovenia (after Froitzheim et al. 2008, Schuster & Stüwe, 2010, Stuewe & Homberger, 2011, mod.) Major steps of Alpine plate tectonic evolution - The Adriatic Plate was part of the African Plate until the Lower Cretaceous ( Adriatic/Apulia Promontory ) - subsequently the Adriatic Plate broke up and started to drift independently - while the Austroalpine unit was detached from the Adriatic Plate during the Lower Cretaceous, the Southalpine was sheared off in southern direction during the Paleogene - today the Austroalpine and Southalpine units are part of the Alpine orogenic wedge which is overlying the plate boundary of the European and Adriatic Plate in the subsurface - anticlockwise rotation of the Adriatic Plate continues today with movements of some mm/y triggering seismicity in Friuli-Venezia Giulia.

58 TECTONIC UNITS DERIVED FROM ADRIATIC MICROPLATE Tectonic block diagram of the Eastern and Southern Alps (Graphics: M. Brüggemann-Ledolter, Geological Survey of Austria)

59 Acknowledgement Graphics: Monika Brüggemann-Ledolter, Geological Survey of Austria Kurt Stuewe, University of Graz Geopark Carnic Alps Photos: Text: Hans P. Schönlaub Ruedi Homberger Internet (Hochobir, Steiner Alps) Hans P. Schönlaub, Ralf Schuster

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61 Back arc volcanics, Riegersburg, Styria

62 Adriatic Plate Southern Alps Adriatic Plate Eastalpine