Lower Continental Crusts Involved in the Alpine Orogeny: New Insight from the Santa Lucia Nappe Metasediments (Corsica, France)

Abstract

In the Alpine Corsica (France), the Santa Lucia Nappe represents a peculiar unit preserving the unique relicts of Paleozoic lower to medium continental crust. It consists of composite basement affected by Permian granulite facies metamorphic conditions unconformably covered by a Late Cretaceous clastic sequence (Tomboni Conglomerate and Tralonca Flysch) affected by polyphase deformation and low-grade-metamorphism. In this work, we present a new reconstruction of the deformation events registered by the Tralonca Flysch during the Alpine orogeny. The D1 phase was testified by rare isoclinal folds. The D2 phase produced a continuous foliation and a map-scale sheath-fold with a top-to-W sense of shear. The D3 phase produced E-verging non-cylindrical folds and S3 crenulation cleavage that is not associated to metamorphic blastesis. We present the first temperature-pressure-deformation (P-T-d) path for the Tralonca Flysch, demonstrating that the Santa Lucia Nappe underwent accretion and then first stage exhumation in the Alpine wedge during the D1 phase with pressure and temperature peaks both occurred under blueschist metamorphic conditions. The D2 phase occurred at lower pressure-temperature conditions during a second stage exhumation. This pressure-temperature-deformation path is comparable with those of the Lower Units (i.e., the subducted continental units of Alpine Corsica) suggesting a common geodynamic history.

Keywords

blueschist-facies metamorphism / P-T-d path / Santa Lucia Nappe / Corsica / Alpine orogen

References

[1] Abbate, E.,Bortolotti, V., and Principi G.,1980. Apennine ophiolites: a peculiar oceanic crust, in Special issue on Tethyan ophiolites, Western area, edited by G. Rocci, Ofioliti,5:59-96.

[2] Alessandri, J.A.,Magne, J.,Pilot, M.D., and Samuel, E.,1977. Le Miocène de la région de Corte-Francardo. Bulletin de la Société Scientifique d’Histoire Naturelle de la Corse,622:51-54.

[3] Amaudric du Chaffaut, S., and Saliot, P.,1979. La region de Corte; secteur cle pour la comprehension du metamorphisme alpin en Corse. Bulletin De La Société Géologique De France,S7-XXI(2):149-154.

[4] Amaudric du Chaffaut, S.,1980. Les Unités Alpines à la marge orientale du massif cristalline corse. Thèse sc., Paris-6,247p.

[5] Amaudric du Chaffaut, S.,Caron, J.M.,Delcey, R., and Lemoine, M.,1972. Données nouvelles sur la stratigraphie des Schistes lustrés de Corse: la série de l’Inzecca. Comparaison avec les Alpes Occidentales et l’Apennin Ligure. C. R. Acad. Sci. Paris,275 D:2611-2614.

[6] Amaudric du Chaffaut, S.,Bonin, B.,Caron, J.M.,Conchon, O.,Rossi, P.,Bimbier, A.,Damiani, L.,Dominici, R.,Heetveld, H., and Rouire, J.,1985. Carte Géologique de la France, feuille Venaco (1114) . BRGM, scale 1:50000, 1 sheet.

[7] Beltrando, M.,Zibra, I.,Montanini, A., and Tribuzio, R.,2013. Crustal thinning and exhumation along a fossil magma-poor distal margin preserved in Corsica: A hot rift to drift transition? Lithos,168:99-112.

[8] Best, M.G.,2003. Igneous and metamorphic petrology. Brigham Young University, Blackwell Publishing,2nd edition,1-758.

[9] Bezert, P., and Caby, R.,1988. Sur l’age post-bartonien des événements tectonométamorphiques alpins en bordure orientale de la Corse cristalline (Nord de Corte). Bulletin de la Société Géologique de France,IV(6):965-971.

[10] Brunet, C.,Monié P.,Jolivet, L., and Cadet, J.P.,2000. Migration of compression and extension in the Tyrrhenian Sea, insights from ⁴⁰Ar/³⁹Ar ages on micas along a transect from Corsica to Tuscany. Tectonophysics,321(1):127-155.

[11] Caby, R., and Jacob, C.,2000. La transition croûte-manteau dans la nappe de Santa-Lucia-di-Mercurio (Corse Alpine): les racines d’un rift permien. Géologie de la France,1:21-34.

[12] Cavazza, W.,DeCelles, P.G.,Fellin, M.G., and Paganelli, L.,2007. The Miocene Saint-Florent Basin in northern Corsica: Stratigraphy, sedimentology, and tectonic implications. Basin Research,19(4):507-527.

[13] Chenin, P.,Schmalholz, S.M.,Manatschal, G., and Karner, G.D.,2018. Necking of the lithosphere: A reappraisal of basic concepts with thermo-mechanical numerical modeling. Journal of Geophysical Research (Solid Earth),123(6):5279-5299.

[14] Dallan, L., and Puccinelli, A.,1995. Geologia della regione tra Bastia e St-Florent (Corsica settentrionale) con Carta geologica alla scala 1:25, 000. Bollettino Della Societa Geologica Italiana,114:23-66.

[15] Di Rosa, M.,De Giorgi, A.,Marroni, M., and Vidal, O.,2017. Syn-convergence exhumation of continental crust: Evidence from structural and metamorphic analysis of the Monte Cecu area, Alpine Corsica (Northern Corsica, France). Geological Journal,52(6):919-937.

[16] Di Rosa, M.,Frassi, C.,Meneghini, F.,Marroni, M.,Pandolfi, L., and De Giorgi, A.,2019a. Tectono-metamorphic evolution of the European continental margin involved in the Alpine subduction: New insights from Alpine Corsica, France. Comptes Rendus Géoscience,351(5):384-394.

[17] Di Rosa, M.,Meneghini, F.,Marroni, M.,Hobbs, N., and Vidal, O.,2019b. The exhumation of continental crust in collisional belts: Insights from the deep structure of Alpine Corsica in theCima Pedani area. The Journal of Geology,127(3):263-288.

[18] Di Rosa, M.,Meneghini, F.,Marroni, M.,Frassi, C., and Pandolfi, L.,2020a. The coupling of high-pressure oceanic and continental units in Alpine Corsica: Evidence for syn-exhumation tectonic erosion at the roof of the plate interface. Lithos,354-355:105328.

[19] Di Rosa, M.,Frassi, C.,Marroni, M.,Meneghini, F., and Pandolfi, L.,2020b. Did the “Autochthonous” European foreland of Corsica Island (France) experience Alpine subduction? Terra Nova,32(1):34-43.

[20] Di Rosa, M.,Frassi, C.,Marroni, M.,Pandolfi, L.,Malasoma, A., and Meneghini, F.,2023a. Pre-collisional architecture of the European distal margin: Inferences from the high-pressure continental units of central Corsica (France). Open Geosciences,15(1):20220575.

[21] Di Rosa, M.,Farina, F.,Marroni, M.,Jeon, H., and Pandolfi, L.,2023b. U-Pb ages from felsic rocks of the External Ligurian sedimentary mélange (Northern Apennine, Italy): Tracing the pre-Jurassic history of the hyperextended Adria continental margin. Journal of the Geological Society,181(1).

[22] Di Rosa, M.,Sanità E.f,Frassi, C.,Lardeaux, J.M.,Corsini, M.,Marroni, M., and Pandolfi, L.,2024. A journey of the continental crust to and from mantle depth: The P-T-t-d path of Venaco unit, Alpine Corsica (France). Geological Journal,59(2):422-440.

[23] Doglioni, C.,1991. A proposal for the kinematic modelling of W-dipping subductions -possible applications to the Tyrrhenian-Apennines system. Terra Nova,3(4):423-434.

[24] Durand-Delga, M.,1984. Principaux traits de la Corse Alpine et correlations avec les Alpes Ligures. Memorie della Società Geologica Italiana,28:285-329.

[25] Egal, E.,1992. Structures and tectonic evolution of the external zone of Alpine Corsica. Journal of Structural Geology,14(10):1215-1228.

[26] Faccenna, C.,Piromallo, C.,Crespo-Blanc, A.,Jolivet, L., and Rossetti, F.,2004. Lateral slab deformation and the origin of the western Mediterranean arcs. Tectonics,23(1):TC1012.

[27] Fellin, M.G.,Picotti, V., and Zattin, M.,2005. Neogene to Quaternary rifting and inversion in Corsica: Retreat and collision in the western Mediterranean. Tectonics,24(1):TC1011.

[28] Ferrandini, M.,Ferrandini, J.,Pilot, M.D.,Butterlin, J.,Loÿe-Pilot Cravatte, J., and Janin, M.C.,1998. Le Miocène du bassin de Saint-Florent(Corse): Modalités de la transgression du Burdigalien supérieur et mise en évidence du Serravallien. Geobios,31(1):125-137.

[29] Ferrandini, J.,Ferrandini, M.,Rossi, P., and Savary-Sismondini, B.,2010. Définition et datation de la Formation de Venaco (Corse): Dépôt d’origine gravitaire d’âge Priabonien. Comptes Rendus Geoscience,342(12):921-929.

[30] Ferrill, D.A.,Morris, A.P.,Evans, M.A.,Burkhard, M.,Groshong, R.H., and Onasch, C.M.,2004. Calcite twin morphology: A low-temperature deformation geothermometer. Journal of Structural Geology,26(8):1521-1529.

[31] Frassi, C.,Di Rosa, M.,Farina, F.,Pandolfi, L., and Marroni, M.,2023. Anatomy of a deformed upper crust fragment from western Alpine Corsica (France): Insights into continental subduction processes. International Geology Review,65(1):40-60.

[32] Forbes, C.J.,Betts, P.G., and Lister, G.S.,2004. Synchronous development of Type 2 and Type 3 fold interference patterns: Evidence for recumbent sheath folds in the Allendale Area, Broken Hill, NSW, Australia. Journal of Structural Geology,26(1):113-126.

[33] Froitzheim, N., and Manatschal, G.,1996. Kinematics of Jurassic rifting, mantle exhumation, and passive-margin formation in the Austroalpine and Penninic nappes (eastern Switzerland). Geological Society of America Bulletin,108(9):1120-1133.

[34] Gueguen, E.,Doglioni, C., and Fernandez, M.,1998. On the post-25 Ma geodynamic evolution of the western Mediterranean. Tectonophysics,298(1-3):259-269.

[35] Gueydan, F.,Brun, J.P.,Phillippon, M., and Noury, M.,2017. Sequential extension as a record of Corsica Rotation during Apennines slab roll-back. Tectonophysics,710:149-161.

[36] Handy, M.R.,Schmid, S.M.,Bousquet, R.,Kissling, E., and Bernoulli, D.,2010. Reconciling plate-tectonic reconstructions of Alpine Tethys with the geological-geophysical record of spreading and subduction in the Alps. Earth-Science Reviews,102(3-4):121-158.

[37] Jolivet, L.,Dubois, R.,Fournier, M.,Goffé B.,Michard, A., and Jourdan, C.,1990. Ductile extension in alpine Corsica. Geology,18(10):1007-1010.

[38] Lacombe, O., and Jolivet, L.,2005. Structural and kinematic relationships between Corsica and the Pyrenees-Provence domain at the time of the Pyrenean orogeny. Tectonics,24:TC1003.

[39] Lagabrielle, Y., and Lemoine, M.,1997. Alpine, Corsican and Apennine ophiolites: The slow-spreading ridge model. Comptes Rendus De L’Académie Des Sciences -Series IIA -Earth and Planetary Science,325(12):909-920.

[40] Lanari, P.,Vidal, O.,De Andrade, V.,Dubacq, B.,Lewin, E.,Grosch, E.G., and Schwartz, S.,2014. XMapTools: A MATLAB©-based program for electron microprobe X-ray image processing and geothermobarometry. Computers & Geosciences,62:227-240.

[41] Laporte, D.,Fernandez, A., and Orsini, J.B.,1991. Le complexe d’île Rousse, Balagne, Corse du Nord-Ouest: pétrologie et cadre de mise en place des granitoïdes magnésiopotassiques. Géologie de France,4:15-30.

[42] Lavier, L.L., and Manatschal, G.,2006. A mechanism to thin the continental lithosphere at magma-poor margins. Nature,440(7082):324-328.

[43] Levi, N.,Malasoma, A.,Marroni, M.,Pandolfi, L., and Paperini, M.,2007. Tectono-metamorphic history of the ophiolitic Lento unit (northern Corsica): Evidences for the complexity of accretion-exhumation processes in a fossil subduction system. Geodinamica Acta,20(1-2):99-118.

[44] Libourel, G.,1985. Le complexe de Santa Lucia di Mercurio (Corse) (Ph.D. thesis),University of Toulouse,1-405.

[45] Libourel, G,1988. Le complexe de Santa-Lucia di Mercurio (Corse): Un nouveau jalon de la base de la croûte varisque en Méditerranee Occidentale. Comptes Rendues de l’Academie de Science Paris,307:1067-1073.

[46] Lin, W.,Rossi, P.,Faure, M.,Li, X.H.,Ji, W., and Chu, Y.,2018. Detrital zircon age patterns from turbidites of the Balagne and Piedmont nappes of Alpine Corsica (France): Evidence for an European margin source. Tectonophysics,722:69-105.

[47] Maggi, M.,Rossetti, F.,Corfu, F.,Theye, T.,Andersen, T.B., and Faccenna, C.,2012. Clinopyroxene-rutile phyllonites from the East Tenda Shear Zone (Alpine Corsica, France): Pressure-temperature-time constraints to the Alpine reworking of Variscan Corsica. Journal of the Geological Society of London,169(6):723-732

[48] Malasoma, A., and Marroni, M.,2007. HP/LT metamorphism in the Volparone Breccia (Northern Corsica, France): Evidence for involvement of the Europe/Corsica continental margin in the Alpine subduction zone. Journal of Metamorphic Geology,25(5):529-545.

[49] Malasoma, A.,Marroni, M.,Musumeci, G., and Pandolfi, L.,2006. High-pressure mineral assemblage in granitic rocks from continental units, Alpine Corsica, France. Geological Journal,41(1):49-59.

[50] Malasoma, A.,Morelli, G.,Di Rosa, M.,Marroni, M.,Pandeli, E.,Principi, G., and Pandolfi, L.,2020. The stratigraphic and structural setting of metamorphic continental units from Alpine Corsica: Clues from the area between Asco and Golo valleys (Central Corsica, France). Journal of Maps,16(2):313-323.

[51] Malavieille, J.,Chemenda, A., and Larroque, C.,1998. Evolutionary model for the Alpine Corsica: Mechanism for ophiolite emplacement and exhumation of high-pressure rocks. Terra Nova,10(6):317-322.

[52] Malusà M.G.,Faccenna, C.,Baldwin, S.L.,Fitzgerald, P.G.,Rossetti, F.,Balestrieri, M.L.,Danišík, M.,Ellero, A.,Ottria, G., and Piromallo, C.,2015. Contrasting styles of (U)HP rock exhumation along the Cenozoic Adria-Europe plate boundary (Western Alps, Calabria, Corsica). Geochemistry, Geophysics, Geosystems,16(6):1786-1824.

[53] Maluski, H.,Mattauer, M., and Matte, P.H.,1973. Sur la présence de décrochements alpins en Corse. Comptes Rendues de l’Academie des Science de Paris,276:709-712.

[54] Manatschal, G., and Chenin, P.,2023. Fossil rifted margins in the Alps. Geological Field Trips,15(1.2):1-207.

[55] Marroni, M., and Pandolfi, L.,2003. Deformation history of the ophiolite sequence from the Balagne Nappe, northern Corsica: Insights in the tectonic evolution of Alpine Corsica. Geological Journal,38(1):67-83.

[56] Marroni, M., and Pandolfi, L.,2007. The architecture of an incipient oceanic basin: A tentative reconstruction of the Jurassic Liguria-Piemonte Basin along the Northern Apennines-Alpine Corsica transect. International Journal of Earth Sciences,96(6):1059-1078.

[57] Marroni, M.,Meneghini, F., and Pandolfi, L.,2017. A revised subduction inception model to explain the Late Cretaceous, double-vergent orogen in the precollisional western Tethys: Evidence from the northern Apennines. Tectonics,36(10):2227-2249.

[58] Massonne, H.J., and Schreyer, W.,1987. Phengite geobarometry based on the limiting assemblage with K-feldspar, phlogopite, and quartz. Contributions to Mineralogy and Petrology,96(2):212-224.

[59] Ménot, R.P., and Orsini, J.B.,1990. Evolution du socle antéstéphanien de Corse: événements magmatiques et métamorphiques. Schweizerische Mineraogische und Petrographische Mittelungen,70:35-53.

[60] Meresse, F.,Lagabrielle, Y.,Malavieille, J., and Ildefonse, B.,2012. A fossil ocean-continent transition of the Mesozoic Tethys preserved in the Schistes Lustrés nappe of northern Corsica. Tectonophysics,579:4-16.

[61] Mohn, G.,Manatschal, G.,Beltrando, M.,Masini, E., and Kusznir, N.,2012. Necking of continental crust in magma-poor rifted margins: Evidence from the fossil Alpine Tethys margins. Tectonics,31(1):TC1012.

[62] Molli, G.,Tribuzio, R., and Marquer, D.,2006. Deformation and metamorphism at the eastern border of the Tenda Massif (NE Corsica): A record of subduction and exhumation of continental crust. Journal of Structural Geology,28(10):1748-1766.

[63] Molli, G,2008. Northern Apennine-Corsica orogenic system: An updated overview. Geological Society, London, Special Publications,298(1):413-442.

[64] Pandolfi, L.,Marroni, M., and Malasoma, A.,2016. Stratigraphic and structural features of the Bas Ostriconi Unit (Corsica): Palaeogeographic implications. Comptes Rendus Géoscience,348(8):630-640.

[65] Paquette, J.L.,Ménot, R.P.,Pin, C., and Orsini, J.B.,2003. Episodic and short-lived granitic pulses in a post-collisional setting: Evidence from precise U-Pb zircon dating through a crustal cross-section in Corsica. Chemical Geology,198(1-2):1-20.

[66] Ribes, C.,Ghienne, J.F.,Manatschal, G.,Dall’Asta, N.,Stockli, D.F.,Galster, F.,Gillard, M., and Karner, G.D.,2020. The Grès Singuliers of the Mont Blanc Region (France and Switzerland): Stratigraphic response to rifting and crustal necking in the Alpine Tethys. International Journal of Earth Sciences,109(7):2325-2352.

[67] Rieuf, M.,1980. Étude stratigraphique et structurale des unités à Nord-Est de Corte (Corse). Thèse Doct. 3° cycle, Un. Paul-Sabatier, Toulouse,1-234.

[68] Rosenbaum, G.,Lister, G.S., and Duboz, C.,2002. Reconstruction of the tectonic evolution of the western Mediterranean since the Oligocene. Journal of the Virtual Explorer,8:107-130.

[69] Rossi, P.,Cocherie, A.,Fanning, C.M., and Deloule, É.,2006. Variscan to Eo-Alpine events recorded in European lower-crust zircons sampled from the French Massif Central and Corsica, France. Lithos,87(3-4):235-260.

[70] Rossi, P.,Oggiano, G., and Cocherie, A.,2009. A restored section of the “southern Variscan realm” across the Corsica-Sardinia microcontinent. Comptes Rendus Géoscience,341(2-3):224-238.

[71] Sanfilippo, A., and Tribuzio, R.,2013. Building of the deepest crust at a fossil slow-spreading centre (Pineto gabbroic sequence, Alpine Jurassic ophiolites). Contributions to Mineralogy and Petrology,165(4):705-721.

[72] Schmid, S.M., and Kissling, E.,2000. The arc of the western Alps in the light of geophysical data on deep crustal structure. Tectonics,19(1):62-85.

[73] Turner, F.J.,1948. Mineralogical and structural evolution of the metamorphic rocks. In: Geological Society of America Memoirs. Geological Society of America,1-332.

[74] Vidal, O., and Parra, T.,2000. Exhumation paths of high-pressure metapelites obtained from local equilibria for chlorite-phengite assemblages. Geological Journal,35(3-4):139-161.

[75] Vitale Brovarone, A.,Beyssac, O.,Malavieille, J.,Molli, G.,Beltrando, M., and Compagnoni, R.,2013. Stacking and metamorphism of continuous segments of subducted lithosphere in a high-pressure wedge: The example of Alpine Corsica (France). Earth-Science Reviews,116:35-56.

[76] Warburton, J.,1986. The ophiolite-bearing Schistes lustrés nappe in Alpine Corsica: A model for the emplacement of ophiolites that have suffered HP/LT metamorphism. In: Geological Society of America Memoirs. Geological Society of America: 313-332.

[77] Waters, C.N.,1990. The Cenozoic tectonic evolution of Alpine Corsica. Journal of the Geological Society of London,147(5):811-824.

[78] Zarki-Jakni, B.,van der Beek, P.,Poupeau, G.,Sosson, M.,Labrin, E.,Rossi, P., and Ferrandini, J.,2004. Cenozoic denudation of Corsica in response to Ligurian and Tyrrhenian extension: Results from apatite fission track thermochronology. Tectonics,23(1):3.1-3.18.

[79] Zibra, I.,Kruhl, J.H., and Braga, R.,2010. Late Palaeozoic deformation of post-Variscan lower crust: Shear zone widening due to strain localization during retrograde shearing. International Journal of Earth Sciences,99(5):973-991.

[80] Zibra, I.,Kruhl, J.H.,Montanini, A., and Tribuzio, R.,2012. Shearing of magma along a high-grade shear zone: Evolution of microstructures during the transition from magmatic to solid-state flow. Journal of Structural Geology,37:150-160.

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