Mantle–crust interactions during Variscan subduction in the Eastern Alps (Nonsberg–Ulten zone): geochronology and new petrological constraints

Tumiati, Simone; Thöni, Martin; Nimis, Paolo; Martin, Silvana; Mair, Volkmar

doi:10.1016/s0012-821x(03)00161-4

Cited by 81 publications

(58 citation statements)

References 36 publications

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“…In contrast, if peak UHP metamorphic temperatures are greater than 750°C and decompression is nearly isothermal or occurs with an increase in temperature, fluid-absent melting of phengite occurs during the exhumation of felsic UHP rocks . This is well documented in examples like the Sulu orogen in China (Nakamura and Hirajima, 2000) and Ulten zone in the Italian Alps (Tumiati et al, 2003).…”

Section: Partial Melting During Exhumationmentioning

confidence: 69%

Element mobility in mafic and felsic ultrahigh-pressure metamorphic rocks during continental collision

Zhao

Zheng

Chen

et al. 2007

Geochimica et Cosmochimica Acta

148

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Section: Partial Melting During Exhumationmentioning

confidence: 69%

Element mobility in mafic and felsic ultrahigh-pressure metamorphic rocks during continental collision

Zhao

Zheng

Chen

et al. 2007

Geochimica et Cosmochimica Acta

148

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“…Sm-Nd and Rb-Sr whole-rock and mineral isotope systematics of garnet peridotites, eclogites and migmatitic gneisses from the Nonsberg-Ulten zone testify that all rock types were isotopically homogenised at ca. 330 Ma (Tumiati et al 2003). Tumiati et al (2003) discuss the hypothesis that the 330-Ma age constraint may reflect the exhumation of the high-pressure unit.…”

Section: The Variscan Orogenymentioning

confidence: 95%

“…330 Ma (Tumiati et al 2003). Tumiati et al (2003) discuss the hypothesis that the 330-Ma age constraint may reflect the exhumation of the high-pressure unit. Precisely, they suggest that slices of subducted crustal material were detached from the lithospheric slab and were driven upwards by buoyancy, incorporating portions of the overlying sinking mantle during their rise.…”

Section: The Variscan Orogenymentioning

confidence: 95%

“…2) is documented at 350 Ma for the Silvretta (Ladenhauf et al 2001) and Ö tztal basement units (Miller and Thöni 1995;Thöni 2006), as well as at 336 Ma for the Nonsberg-Ulten zone (Tumiati et al 2003(Tumiati et al , 2007. The time difference of about 15 Ma between the Silvretta-Ö tztal eclogites and the high-pressure association, including eclogites, migmatites and mantle peridotites, of the Ulten zone (Tumiati et al 2003) suggests that eclogite metamorphism within the Austroalpine basement was diachronous. Sm-Nd and Rb-Sr whole-rock and mineral isotope systematics of garnet peridotites, eclogites and migmatitic gneisses from the Nonsberg-Ulten zone testify that all rock types were isotopically homogenised at ca.…”

Section: The Variscan Orogenymentioning

confidence: 97%

“…Migmatite formation at 490 Ma in the Winnebach area (WM) is closely coeval with the opening of the ocean documented by Chamrousse ophiolite (Helvetic Belledonne Massif), and suggests that the Austroalpine basement has been involved in the extensional tectonics that resulted in the oceanisation of the back-arc in the Middle Cambrian. Variscan eclogites (Vec) in Silvretta and Ö tztal basements formed at 350 Ma (Thöni 2006), whilst in Nonsberg-Ulten area, south of Meran (M), eclogites formed at 336 Ma (Tumiati et al 2003(Tumiati et al , 2007. In Silvretta and Ö tztal basements, mega-folds with subvertical axes formed during the Variscan orogeny (''Schlingen-Tektonik'': ST).…”

Section: The Cambrian-ordovician Cyclementioning

confidence: 99%

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The crystalline basement of the Adria microplate in the eastern Alps: a review of the palaeostructural evolution from the Neoproterozoic to the Cenozoic

Spiess

Cesare

Mazzoli

et al. 2010

Rend. Fis. Acc. Lincei

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The frontal northern part of the continental Adriatic microplate is formed by a stack of Austroalpine nappes and by the Southalpine basement and cover units. Both basement portions are now side by side, separated by the Periadriatic (Insubric) fault system, but they became juxtaposed only during the Alpine orogeny. Permian HT-LP metamorphism is now recognised also within the Austroalpine basement of the eastern Alps, whilst it was known since long in the Southalpine basement. High thermal heat flow responsible for HT-LP metamorphism is related to the extensional tectonics and lithospheric thinning during the Permian and by concurrent magmatic underplating. During the Variscan orogeny, eclogite facies metamorphism is documented within the Ö tztal and the Silvretta basements (350 Ma), as well as within the Nonsberg-Ulten unit (336 Ma). The HP events in the Ö tztal and the Silvretta basements correlate temporarily with the closure of the Rheic Ocean between the Hanseatic and the Galatian terranes. Docking of the Galatian-Hanseatic composite terrane with Laurussia resulted in large-scale strike-slip tectonics and potentially in the formation of mega-folds (''Schlingen'') within the Austroalpine basement during the Visean. Palaeo-Tethys ridge subduction may be responsible for fast decompression and isobaric heating documented within the Ö tztal basement. The Palaeozoic sedimentary sequences of the Austroalpine and the Southalpine phyllitic complexes testify that from Silurian to Devonian, both basement portions were in a passive margin position. During the Cambrian-Ordovician, the Austroalpine basement occupied a position along the leading edge of Gondwana facing the Proto-Tethys Ocean. The compositional variation of the intruded granitic suites confirm an evolution from a magmatic arc towards a collisional-type geodynamic setting related to the closure of the previously opened back-arc basins.

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The Grand St Bernard‐Briançonnais Nappe System and the Paleozoic Inheritance of the Western Alps Unraveled by Zircon U‐Pb Dating

et al. 2017

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The continental crust involved in the Alpine orogeny was largely shaped by Paleozoic tectono‐metamorphic and igneous events during oblique collision between Gondwana and Laurussia. In order to shed light on the pre‐Alpine basement puzzle disrupted and reamalgamated during the Tethyan rifting and the Alpine orogeny, we provide sensitive high‐resolution ion microprobe U‐Pb zircon and geochemical whole rock data from selected basement units of the Grand St Bernard‐Briançonnais nappe system in the Western Alps and from the Penninic and Lower Austroalpine units in the Central Alps. Zircon U‐Pb ages, ranging from 459.0 ± 2.3 Ma to 279.1 ± 1.1 Ma, provide evidence of a complex evolution along the northern margin of Gondwana including Ordovician transtension, Devonian subduction, and Carboniferous‐to‐Permian tectonic reorganization. Original zircon U‐Pb ages of 371 ± 0.9 Ma and 369.3 ± 1.5 Ma, from calc‐alkaline granitoids of the Grand Nomenon and Gneiss del Monte Canale units, provide the first compelling evidence of Late Devonian orogenic magmatism in the Alps. We propose that rocks belonging to these units were originally part of the Moldanubian domain and were displaced toward the SW by Late Carboniferous strike‐slip faulting. The resulting assemblage of basement units was disrupted by Permian tectonics and by Mesozoic opening of the Alpine Tethys. Remnants of the Moldanubian domain became either part of the European paleomargin (Grand Nomenon unit) or part of the Adriatic paleomargin (Gneiss del Monte Canale unit), to be finally accreted into the Alpine orogenic wedge during the Cenozoic.

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Mantle–crust interactions during Variscan subduction in the Eastern Alps (Nonsberg–Ulten zone): geochronology and new petrological constraints

Cited by 81 publications

References 36 publications

Element mobility in mafic and felsic ultrahigh-pressure metamorphic rocks during continental collision

Element mobility in mafic and felsic ultrahigh-pressure metamorphic rocks during continental collision

The crystalline basement of the Adria microplate in the eastern Alps: a review of the palaeostructural evolution from the Neoproterozoic to the Cenozoic

The Grand St Bernard‐Briançonnais Nappe System and the Paleozoic Inheritance of the Western Alps Unraveled by Zircon U‐Pb Dating

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