Thermal history of the Maramureş area (Northern Romania) constrained by zircon fission track analysis: Cretaceous metamorphism and Late Cretaceous to Paleocene exhumation

Gröger, Heike R.; Tischler, Matthias M.; Fügenschuh, Bernhard; Schmid, M.

doi:10.2478/geoca-2013-00026

Cited by 4 publications

(8 citation statements)

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“…This clearly post-dates the intrusion of the Fanos granite (158 Ma) (Anders et al 2005) associated with these ophiolites and constrains the timing of obduction in the Demir Kapija area rather precisely and within a time range (158-152 Ma) that is very similar to that obtained for the Apuseni Mountains. The Late Jurassic emplacement of the East Vardar ophiolites in the Apuseni Mountains was followed by Early Cretaceous thrusting of the East Vardar ophiolites across the present-day Transylvanian basin all the way to the Eastern Carpathians (Gröger et al 2013) and also led to the collision of the Dacia and Tisza Mega-Units in the area of the Apuseni Mountains during the Early Cretaceous orogeny (e.g. Kounov and Schmid 2013).…”

Section: Geodynamic Modelmentioning

confidence: 99%

Magmatic and tectonic history of Jurassic ophiolites and associated granitoids from the South Apuseni Mountains (Romania)

et al. 2016

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The Jurassic ophiolites in the South Apuseni Mountains represent remnants of the Neotethys Ocean and belong to the East Vardar ophiolites that contain ophiolite fragments as well as granitoids and volcanics with island-arc affinity. New U-Pb zircon ages, and Sr and Nd isotope ratios give insights into their tectono-magmatic history. The ophiolite lithologies show tholeiitic MOR-type affinities, but are occasionally slightly enriched in Th and U, and depleted in Nb, which indicates that they probably formed in a marginal or back-arc basin. These ophiolites are associated with calc-alkaline granitoids and volcanics, which show trace element signatures characteristic for subduction-enrichment (high LILE, low HFSE). Low 87 Sr/ 86 Sr ratios (0.703836-0.704550) and high 143 Nd/ 144 Nd ratios (0.512599-0.512616) of the calc-alkaline series overlap with the ratios measured in the ophiolitic rocks (0.703863-0.704303 and 0.512496-0.512673), and hence show no contamination with continental crust. This excludes a collisional to postcollisional origin of the granitoids and is consistent with the previously proposed intra-oceanic island arc setting. The new U-Pb ages of the ophiolite lithologies (158.9-155.9 Ma, Oxfordian to Early Kimmeridgian) and granitoids (158.6-152.9 Ma, latest Oxfordian to Late Kimmeridgian) indicate that the two distinct magmatic series evolved within a narrow time range. It is proposed that the ophiolites and island arc granitoids formed above a long-lived NE-dipping subduction zone. A sudden flip in subduction polarity led to collision between island arc and continental margin, immediately followed by obduction of the ophiolites and granitoids on top of the continental margin of the Dacia Mega-Unit. Since the granitoids lack crustal input, they must have intruded the Apuseni ophiolites before both magmatic sequences were obducted onto the continental margin. The age of the youngest granitoid (~153 Ma, Late Kimmeridgian) yields an estimate for the maximum age of emplacement of the South Apuseni ophiolites and associated granitoids onto the Dacia Mega-Unit.

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Section: Geodynamic Modelmentioning

confidence: 99%

Magmatic and tectonic history of Jurassic ophiolites and associated granitoids from the South Apuseni Mountains (Romania)

et al. 2016

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“…Dur ing this pe riod, crys tal line com plexes of the Dacia Mega-Unit were el e vated (e.g., Hnylko, 2011a, c). Al beit burial is in di cated for the NW part of the Transylvania Ba sin (in clud ing the Preluca Mas sif), East and SE Carpathians dur ing Mid dle Eocene to Oligocene Gröger et al, 2013), small parts of crys tal line base ment in the north ern part of the East ern Carpathians (as shown by the AHe ages of ap a tite -cf. Merten, 2011: fig.…”

Section: Palaeogeographic Implicationsmentioning

confidence: 99%

Heavy minerals from sedimentary rocks of the Malcov Formation and their palaeogeographic implications for evolution of the Magura Basin (Western Carpathians, Slovakia) during the Late Eocene – Late Oligocene

Bónová

Bóna²,

Kováčik

et al. 2016

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“…In the East Carpathians there were also Alpine nappe stacking events, summarised by Săndulescu (1984), in which shear zones were identified a HP/LT dynamic metamorphic processes overprinted on the Variscan metamorphic basement (Balintoni et al, 1983;Kräutner, 1988;Kräutner, 1996;Munteanu and Tatu, 2003;Balintoni and Balica, 2013;Balintoni et al, 2014). Such an Alpine shear zone in Maramureş Mountains contains the tourmalines studied here (Zincenco et al, 1982;Zincenco, 1995;Kräutner and Bindea, 2002;Gröger, 2006). The question arises as to how this tourmaline can retain information regarding metamorphic evolution of its host rocks implied in an Alpine shear zone at pressures and temperatures much lower than in Alps.…”

Section: Introductionmentioning

confidence: 59%

Metamorphic tourmaline and its petrogenetic significance from the Maramureș Mountains (East Carpathians, Romania)

Mosonyi

Forray

2022

Austrian Journal of Earth Sciences

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This study describes mineralogical and crystallochemical characteristics of metamorphic tourmalines from an Alpine shear zone in a Variscan metamorphic rock sequence from the Maramures region in the northern part of the East Carpathians. We use this mineral to unravel aspects of the evolution of the tourmaline bearing host rocks and compare the crystallo-chemical characteristics to other tourmalines from Alps. Petrographic and microstructural observations, as well as electron microprobe analyses on several zoned tourmalines and associated minerals (mica, feldspar) from mylonitic schist of the Rebra terrane (Maramureș Mountains), indicate that the pre-kinematic tourmalines belong to the alkali group (Na dominant), hydroxyl dominated on the crystallographic W-site and can be assigned to the species dravite and schorl. The tourmaline-bearing rocks have a metasedimentary protolith. The analysed porphyroblasts, rotated by simple shear, show corroded rim that are interpreted to have formed due to pressure release. Three main compositional zones were evidenced on a tourmaline porphyroblast: a core zone and two asymmetrically arranged inclusion-poor/free rims, all formed in pre-alpine prograde metamorphic conditions. Based on mineral microstructural relations and geothermobarometry (tourmaline–muscovite, tourmaline–plagioclase geothermometry and phengite geobarometry), the metamorphic peak conditions of the investigated Rebra terrane were evaluated to have been at a temperature of ca. 590 to 620 ± 22 °C and Pmin = 5.5 - 6.0 ± 0.5 kbar. By observing dynamically recrystallized microstructures in quartz and feldspar in the shear zone a temperature of 350 - 400 °C was estimated and the quartz paleopiezometry outlined a differential stress of about 1.5 kbar that implied only minor chemical change in tourmaline outer zone.

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Thermal history of the Maramureş area (Northern Romania) constrained by zircon fission track analysis: Cretaceous metamorphism and Late Cretaceous to Paleocene exhumation

Cited by 4 publications

References 0 publications

Magmatic and tectonic history of Jurassic ophiolites and associated granitoids from the South Apuseni Mountains (Romania)

Magmatic and tectonic history of Jurassic ophiolites and associated granitoids from the South Apuseni Mountains (Romania)

Heavy minerals from sedimentary rocks of the Malcov Formation and their palaeogeographic implications for evolution of the Magura Basin (Western Carpathians, Slovakia) during the Late Eocene – Late Oligocene

Metamorphic tourmaline and its petrogenetic significance from the Maramureș Mountains (East Carpathians, Romania)

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