Research themes
As a ATER at the LPGN at the University of Nantes (France), I am interested in suture markers of the Variscan geodynamic evolution in the Southern Carpathian-Balkan region. My research area is currently focused on the “Balkan Carpathian ophiolite”, located in Romania, Serbia and Bulgaria. The subject of my thesis partly concerns the processes involved during thrusting of the oceanic lithosphere onto the continental passive margin. In the studied ophiolite, these processes are expressed by a localized mylonitic zone characterized by gabbro-derived listvenites, which could correspond to the obduction sole. Besides the obduction mechanisms, I have interests in the syn-oceanic processes, especially concerning fluid-rocks interactions (ocean-floor metamorphism, metasomatism, deformations), but also in the structure and composition of current oceanic ridges, a subject that can help characterising ophiolites (accretion mechanisms, spreading rate, etc.).
The study extends also on the enclosing units of the ophiolite, in which deformed rocks have been distinguished (low grade/ high grade metamorphic rocks, magmatic intrusions, etc.), and deals thus with the Variscan regional geology of this area, from the Devonian accretion of the oceanic crust to the emplacement and cooling of Carboniferous granitoids.
To conduct this study, several fieldtrips (sampling and detailed mapping both petrographically and structurally) were carried out for the past four years in the Southern Carpathian-Balkan area with the collaboration of Romania, Serbia and France. The structural study includes both field observations and microtectonics (as well as AMS for the granitoid bodies). The analytical tools used after microscopic observations are principally electron microprobe and scanning electron microscope, in the aim of mineralogical analyses and geothermobarometric studies. In addition, geochemical analyses (major- and trace-elements) are performed to characterize the listvenitic metasomatism as well as the geodynamic context of accretion of the Balkan Carpathian oceanic lithosphere. Finally, radiometric data (40Ar-39Ar, Sm-Nd) have been used to constrain the timing of the different processes (accretion, obduction, collision?).
Publications
Published
(1) Plissart, G. , Féménias, O., Maruntiu, M., Diot, H. & D. Demaiffe (2009): Mineralogy and Geothermometry of gabbro-derived Listvenites in the Tisovita-Iuti Ophiolite, Southwestern Romania. The Canadian Mineralogist, 47 , 1, 81-105.
(2) Berger, J., Féménias, O., Ohnenstetter, D., Plissart, G. , Mercier, J-C.C. (2010): Origin and tectonic significance of corundum-kyanite-sapphirine amphibolites from the French Massif Central. Journal of Metamorphic Geology, 28 , 341-360.
3) Berger, J., Féménias, O., Ohnenstetter, D., Bruguier, O., Plissart, G. , Mercier, J-C.C., Demaiffe, D. (2010): New occurrence of UHP eclogites in Limousin (French Massif Central): Age, tectonic setting and fluid–rock interactions. Lithos, 118 , 365-382.
(4) Plissart, G., Diot, H., Monnier, C., Mărunţiu, M., Berger, J. (2012) Relationship between a syntectonic granitic intrusion and a shear zone in the Southern Carpathian-Balkan area (Almăj Mountains, Romania): implications for Late Variscan kinematics and Cherbelezu granitoid emplacement. Journal of Structural geology, 39, 83-102.
International meetings
(1) Plissart, G., Diot, H., Maruntiu, M., Féménias, O., Berza, T., Launeau, P. (2007) Syn-orogenic granitic magma emplacement during transpressional phase: The Variscan Cheberlezu Massif (Southern Carpathians, Romania). Oral communication, 3MA International Symposium, Fez, Morocco
(2) Plissart, G., Maruntiu, M., Féménias, O., Diot, H., Berza, T., Demaiffe, D. (2007) Metasomatism in the Variscan Tisovita-Iuti ophiolite (Southern Carpathians, Romania). Oral communication, IGCP 497, El Jadida, Morocco
(3) Féménias, O., Berger, J., Plissart, G., Demaiffe, D. (2007) Geotectonic signification of UHP eclogites associated with the Variscan Limousin ophiolite (French Massif Central). Poster, IGCP 497, El Jadida, Morocco
(4) Plissart, G., Maruntiu, M., Féménias, O., Diot, H., Demaiffe, D. (2008) Chromian paragenesis from gabbro-derived listvenites in the Tisovita-Iuti ophiolite (Romania): a two-stage metasomatic origin. Oral communication, Symposium scientifique national "Mircea Savul", Iasi, Romania
(5) Plissart, G., Féménias, O., Maruntiu, M., Diot, H., Cvetkovic, V., Saric, K., Demaiffe, D. (2008) Gabbro-derived listvenites from the Variscan "Danubian" ophiolite: remnant of an ancient oceanic detachment fault? Poster, workshop "Ophiolites and the paleogeographic and tectonic reconstruction of the Alpine-Carpathian-Dinaric orogenic belt", Salzburg, Austria
(6) Plissart, G., Maruntiu, M., Monnier, C., Diot, H. (2009) Destabilization of spinel from podiform chromitites : symplectitic rim of (Cr-Fe) spinel / Cr-rich Mg chlorite and development of a chlorite aureole. Oral communication, Alpine ophiolites and Modern Analogues, Parma, Italy
(7) Plissart, G., Maruntiu, M., Monnier, C., Demaiffe, D., Diot, H. (2009) A petro-structural study of metagabbros and gabbro-derived listvenitic schists: obduction related-deformations in an intra-oceanic setting. Poster, Alpine ophiolites and Modern Analogues, Parma, Italy
(8) Plissart, G., Monnier, C., Maruntiu, M., Neubauer, F., Diot, H. (2010) New Variscan 40Ar-39Ar ages for the Danubian ophiolite. Poster, AGU Chapman Conference on Detachments in Oceanic lithosphere: Deformation, Magmatism, Fluid Flow and Ecosystems, Agros, Cyprus
(9) Plissart, G., Monnier, C., Maruntiu, M., Neubauer, F., Demaiffe, D., Diot, H. (2010) New structural data and 40Ar-39Ar ages from the Danubian ophiolitic sole: implications for the Variscan collision. Oral communication, IMA 2010 Bonds & Bridges, Budapest, Hungary
(10) Plissart, G., Maruntiu, M., Neubauer, F., Monnier, C., Demaiffe, D., Diot, H. (2010) New insights on the occurrence of a Variscan suture in the Upper Danubian Nappe (Romania, Serbia, Bulgaria) evidenced by 40Ar – 39Ar geochronology. Oral communication, XIX CBGA, Thessaloniki, Greece
(11) Plissart G., Diot H., Monnier C., Maruntiu M., Neubauer F., Genser J., Demaiffe D. (2010) Occurrence of a mylonitic zone developed on oceanic and sedimentary rocks (Almaj Mountains, Romania): record of the obduction of the Danubian ophiolite ? Poster, Tectonic Crossroads, Ankara, Turkey
(12) Plissart G., Diot H., Monnier C., Maruntiu M. (2011) Contribution of the Corbu Mylonitic Zone to the emplacement and cooling of the Carboniferous Cherbelezu granitoid (Almaj Mountains, Romania). Oral communication, 3MA International Symposium, Kénitra, Morocco
(13) Plissart G., Monnier C., Diot H., Mărunţiu M, Neubauer F, Demaiffe D, Debaille, V. (2012) Recording of the easternmost Variscan ophiolitic complex: accretion and obduction of the Balkan-Carpathian oceanic crust (BCO - Romania, Serbia, Bulgaria) evidenced by Sm-Nd and Ar-Ar geochronology. Oral communication, Variscan 2012 Congress, Sassari, Sardinia
(14) Plissart, G., Diot, H., Monnier, C., Mărunţiu, M., Berger, J. (2012) Investigations of the role of a mylonitic zone as contributor of the final mush emplacement and the solid-state deformation of a granitoid pluton: implications for Late Variscan kinematics in the Southern Carpathians (Romania). Poster, Variscan 2012 Congress, Sassari, Sardinia
