Journal: International Journal of Earth Sciences

Abbreviation

Int J Earth Sci (Geol Rundsch)

Publisher

Springer

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ISSN

1437-3254
1437-3262

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Publications 1 - 10 of 71
  • Revealing exhumation of the central Alps during the Early Oligocene by detrital zircon U-Pb age and fission-track double dating in the Taveyannaz Formation
    Item type: Journal Article
    Lu, Gang; Fellin, Maria Giuditta; Winkler, Wilfried; et al. (2020)
    International Journal of Earth Sciences
    The late Eocene-to-early Oligocene Taveyannaz Formation is a turbidite series deposited in the Northern Alpine Foreland Basin (close to the Alpine orogenic front). Double dating of zircons with the fission-track and the U-Pb methods is applied on samples from the Taveyannaz Formation to reconstruct the exhumation history of the Central-Western Alps and to understand the syn-collisional magmatism along the Periadriatic lineament. Three samples from this unit show similar detrital zircon fission-track age populations that center at: 33-40 Ma (20%); 69-92 Ma (30-40%); and 138-239 Ma (40-50%). The youngest population contains both syn-volcanic and basement grains. Combined with zircon U-Pb data, it suggests that the basement rocks of Apulian-affinity nappes (Margna Sesia, Austroalpine) were the major sources of detritus, together with the Ivrea Zone and recycled Prealpine flysch, that contributed debris to the Northern Alpine Foreland Basin. Furthermore, the rocks of the Sesia-Lanzo Zone or of equivalent units exposed at that time presumably provided the youngest basement zircon fission-track ages to the basin. The Biella volcanic suite was the source of volcanogenic zircons. Oligocene sediment pathways from source to sink crossed further crystalline basement units and sedimentary covers before entering the basin from the southeast. The lag times of the youngest basement age populations (volcanic zircons excluded) are about 11 Myr. This constrains average moderate-to-high exhumation rate of 0.5-0.6 km/Myr in the pro-side of the orogenic wedge of the Central Alps during the late Eocene to early Oligocene.
  • Metamorphic conditions and structural evolution of the Kesebir-Kardamos dome
    Item type: Journal Article
    Moulas, Evangelos; Schenker, Filippo L.; Burg, Jean-Pierre; et al. (2017)
    International Journal of Earth Sciences
    The synmetamorphic nappe system of the Rhodope Metamorphic Complex has been deformed into dome-and-basin structures attributed to syn- to post-convergent exhumation. We document the deformation style and present new thermobarometric and geochronological constraints for the Kesebir–Kardamos dome in southern Bulgaria and northern Greece. The dome consists of a migmatitic core overlain by high-grade thrust sheets. Kinematic indicators indicate a continuum from ductile to brittle conditions during exhumation. Thermodynamic modeling applied to the high-grade, intermediate thrust sheets yielded peak conditions of 1.2 GPa and ca 730 °C. New U–Pb SHRIMP-II dating of zircons from rocks of the same unit revealed Late Jurassic–Early Cretaceous (145 Ma) as the time of metamorphic crystallization; some zircon rims yielded Eocene ages (53 and 44 Ma) interpreted as having been thermally reset owing to coeval granitoid magmatism. The high-grade rocks were covered by Lutetian–Priabonian marine sediments after exhumation. Slumps suggest that sedimentation took place in a tectonically active environment. Our new structural, petrological and geochronological results suggest that the major shear zone in the core of the Kesebir-Kardamos dome is equivalent to the Late Jurassic–Early Cretaceous Nestos Shear Zone. Post-Jurassic metamorphic ages recorded in the Rhodope most likely represent crustal rather than deep subduction geodynamic processes.
  • Metasomatism of ferroan granites in the northern Aravalli orogen, NW India: geochemical and isotopic constraints, and its metallogenic significance
    Item type: Journal Article
    Kaur, Parampreet; Chaudhri, Naveen; Hofmann, Albrecht W.; et al. (2014)
    International Journal of Earth Sciences
  • Characteristics and timing of hydrothermal fluid circulation in the fossil Pyrenean hyperextended rift system: new constraints from the Chainons Bearnais (W Pyrenees)
    Item type: Journal Article
    Incerpi, Nicolò; Manatschal, Gianreto; Martire, L.; et al. (2020)
    International Journal of Earth Sciences
  • A distal record of the Middle Miocene silicic eruption of the Carpathian-Pannonian Region stored within the Dinaride Lake System: implications for tephrostratigraphy and emplacement of volcaniclastic deposits
    Item type: Journal Article
    Brlek, Mihovil; Trinajstić, Nina; Schindlbeck-Belo, Julie Christin; et al. (2024)
    International Journal of Earth Sciences
    Reliable reconstructions of tephrostratigraphy and emplacement mechanisms of Early to Middle Miocene volcaniclastic deposits across the Alpine-Mediterranean region may yield important clues as to the nature, spread, volume, magnitude and frequency of large silicic eruptions of the Carpathian-Pannonian Region. Here we report on a sequence of Middle Miocene volcaniclastic deposits intercalated with lacustrine strata from the Livno-Tomislavgrad Basin, part of the Dinaride Lake System. We applied a multi-proxy approach to elucidate their source, decipher their emplacement mechanism, and evaluate their basin-scale and regional correlativity. New high-precision zircon geochronology (similar to 14.32 Ma) reveals their simultaneity with numerous volcaniclastic deposits (and their alteration products) widely spread across the Alpine-Mediterranean region. Additionally, their correlativity is confirmed at the scale of the Livno-Tomislavgrad Basin, based on similar lithostratigraphy, mineralogy and volcanic glass geochemistry. Newly obtained zircon Hf isotope data imply that Livno-Tomislavgrad Basin distal volcaniclastic deposits and similar to 14.36 Ma Harsany ignimbrite of the Carpathian-Pannonian Region had shared a parental eruptive center. However, different volcanic glass geochemistry, bolstered by the high-precision geochronology, suggests distinct eruption events, implying more frequent explosive volcanism of the Carpathian-Pannonian Region during Middle Miocene than previously recognized. We suggest that the similar to 14.32 Ma fine fallout tephra, deposited in the distal basin in the Dinarides (> 400 km from the source), was likely re-mobilized by water-driven hillside erosion from the extensive paleo-relief, and further transported via land-derived gravity flows. Upon entering the lake, the gravity flows likely transformed into subaqueous sediment density flows. These deposited similar to 1 to 7-m-thick overall graded volcaniclastic turbidites, thinning away from the presumed source of tephra re-mobilization. Although over-thickened, the similar to 14.32 Ma Livno-Tomislavgrad Basin volcaniclastic deposits can still serve as a reliable tephro- and tectono-stratigraphic markers due to their rapid mode of accumulation.
  • The Valais units in Savoy (France)
    Item type: Journal Article
    Loprieno, Andrea; Bousquet, Romain; Bucher, Stefan; et al. (2011)
    International Journal of Earth Sciences
  • The geometry of continental displacement and its application to Arctic geology
    Item type: Journal Article
    Letsch, Dominik (2013)
    International Journal of Earth Sciences
  • Mesozoic–Tertiary structural evolution of an extensional gneiss dome
    Item type: Journal Article
    Bonev, Nikolay; Burg, Jean-Pierre; Ivanov, Zivko (2006)
    International Journal of Earth Sciences
  • Protracted, coeval crust and mantle melting during Variscan late-orogenic evolution: U-Pb dating in the eastern French Massif Central
    Item type: Journal Article
    Laurent, Oscar; Couzinié, Simon; Zeh, Armin; et al. (2017)
    International Journal of Earth Sciences
    The late stages of the Variscan orogeny are characterized by middle to lower crustal melting and intrusion of voluminous granitoids throughout the belt, which makes it akin to “hot” orogens. These processes resulted in the development of large granite–migmatite complexes, the largest of which being the 305–300-Ma-old Velay dome in the eastern French Massif Central (FMC). This area also hosts a wide range of late-Variscan plutonic rocks that can be subdivided into four groups: (i) cordierite-bearing peraluminous granites (CPG); (ii) muscovite-bearing peraluminous granites (MPG); (iii) K-feldspar porphyritic, calc-alkaline granitoids (KCG) and (iv) Mg–K-rich (monzo)diorites and lamprophyres (“vaugnerites”). New results of LA-SF-ICP-MS U–Pb zircon and monazite dating on 33 samples from all groups indicate that both granites and mafic rocks emplaced together over a long period of ~40 million years throughout the Carboniferous, as shown by intrusion ages between 337.4 ± 1.0 and 298.9 ± 1.8 Ma for the granitoids, and between 335.7 ± 2.1 and 299.1 ± 1.3 Ma for the vaugnerites. Low zircon saturation temperatures and abundant inherited zircons with predominant late Ediacaran to early Cambrian ages indicate that the CPG and MPG formed through muscovite or biotite dehydration melting of ortho- and paragneisses from the Lower Gneiss Unit. The KCG and vaugnerites contain very few inherited zircons, if any, suggesting higher magma temperatures and consistent with a metasomatized lithospheric mantle source for the vaugnerites. The KCG can be explained by interactions between the CPG/MPG and the vaugnerites, or extensive differentiation of the latter. The new dataset provides clear evidence that the eastern FMC was affected by a long-lived magmatic episode characterized by coeval melting of both crustal and mantle sources. This feature is suggested here to result from a lithospheric-scale thermal anomaly, triggered by the removal of the lithospheric mantle root. The spatial distribution of the dated samples points to a progressive southward delamination of the lithospheric mantle, perhaps in response to rollback following continental subduction, or to “retro-delamination” owing to the retreat of a south-verging subduction zone.
Publications 1 - 10 of 71