Stratigraphy of the Haut Var Paleogene continental series (Northeastern Provence, France): New insight on the age of the ‘Sables bleutés du Haut Var’ Formation. Jean Philip, Monique Vianey-Liaud, Carles Martin-Closas, Rodolphe Tabuce, Philippe Léonide, Jean-Pierre Margerel, Joyce Noël To cite this version: Jean Philip, Monique Vianey-Liaud, Carles Martin-Closas, Rodolphe Tabuce, Philippe Léonide, et al.. Stratigraphy of the Haut Var Paleogene continental series (Northeastern Provence, France): New insight on the age of the ‘Sables bleutés du Haut Var’ Formation.. Geobios, Elsevier Masson, 2017, 10.1016/j.geobios.2017.06.002. hal-01574331 HAL Id: hal-01574331 https://hal-amu.archives-ouvertes.fr/hal-01574331 Submitted on 17 Aug 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Accepted Manuscript Title: Stratigraphy of the Haut Var Paleogene continental series (Northeastern Provence, France): new insight on the age of the ‘Sables bleutes´ du Haut Var’ Formation Author: Jean Philip Monique Vianey-Liaud Carles Martin-Closas Rodolphe Tabuce Philippe Leonide´ Jean Pierre Margerel Joyce Noel¨ PII: S0016-6995(16)30069-9 DOI: http://dx.doi.org/doi:10.1016/j.geobios.2017.06.002 Reference: GEOBIO 786 To appear in: Geobios Received date: 8-9-2016 Revised date: 9-5-2017 Accepted date: 18-6-2017 Please cite this article as: Philip, J., Vianey-Liaud, M., Martin-Closas, C., Tabuce, R., Leonide,´ P., Margerel, J.P., Noel,¨ J.,Stratigraphy of the Haut Var Paleogene continental series (Northeastern Provence, France): new insight on the age of the ‘Sables bleutes´ du Haut Var’ Formation, Geobios (2017), http://dx.doi.org/10.1016/j.geobios.2017.06.002 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Stratigraphy of the Haut Var Paleogene continental series (Northeastern Provence, France): new insight on the age of the ‘Sables bleutés du Haut Var’ Formation Jean Philip a,*, Monique Vianey-Liaud b, Carles Martin-Closas c, Rodolphe Tabuce b, Philippe Léonide a, Jean Pierre Margerel a, Joyce Noël d a Aix Marseille Univ, CNRS, IRD, Coll France, CEREGE, Aix-en-Provence, France b Institut des Sciences de l‟Évolution (UM, CNRS, IRD, EPHE), Université Monpellier, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France c Departament de Dinàmica de la Terra, de l‟Oceà. Facultat de Geologia, Universitat de Barcelona-UB, 08208 Barcelona, Catalonia, Spain d Centre de recherche sur la paléobiodiversité et les paléoenvironnements UMR 7207, Université Pierre et Marie Curie, 4 Place Jussieu, 75005 Paris, France * Corresponding author. E-mail address: [email protected] (J. Philip). Corresponding editor: Gilles Escarguel. Abstract The age ofAccepted the Paleogene deposits of the Haut Manuscript Var (Provence, France) has been the subject of debate. Particularly, the „Calcaire à Bithynies‟ and the „Sables bleutés‟ units were ascribed either to the early Eocene or to the Oligocene. A stratigraphical clarification is required in order to precise the paleogeographical relationships of the Haut Var Paleogene sedimentary series with coeval deposits in the neighbouring southern Provence and Subalpine regions and other European domains. The study area is characterized by tectonically separated synclines and grabens filled in by continental Paleogene deposits. Detailed mapping and lithostratigraphical Page 1 of 62 logging, sedimentological and microfacies analysis have been undertaken in order to provide a reliable stratigraphical framework. Biostratigraphical subdivisions were established based on five different fossil groups: mammals, charophytes, gastropods, ostracodes, and foraminifers. Accordingly, five formations are distinguished and dated: „Calcaire à Microcodium‟ and „Brèche à Microcodium‟ (Danian); „Marnes à oeufs d‟oiseaux‟ (Selandian(?)-earliest Ypresian); „Sables bleutés du Haut Var‟ (early-late(?) Ypresian); and „Bourdas conglomerates‟ (Rupelian). Particular emphasis is given to the study of the controversial „Sables bleutés du Haut Var‟ Formation. As a result, correlations have been established between the different syncline and graben areas where Paleocene-Eocene and Oligocene deposits occur. Terrestrial deposits (carbonate paleosols and piedmont alluvial fans) took place during Paleocene times, while fluvial (cross-bedded sands) and lacustrine carbonate deposits developed in a foreland compressional intracontinental basin surrounded by emerged areas and tectonic highs during the early Ypresian. Paleoenvironmental and paleogeographical analysis strengthen the view that a relative isolation characterized the Haut Var area during the early Eocene, probably enhancing episodes of brackish water or evaporitic sedimentation and gastropod endemism. During the late Eocene Pyrenean-Provence tectonic phase, the E-W trending Haut Var overthrusts have been emplaced posteriorly to the deposition of the „Sables bleutés du Haut Var‟ Fm. Finally, coarse alluvial fan and local lacustrine carbonate sedimentation occurred during the Oligocene in narrow N-S trending subsident extensional grabens associated with the N-S trending Barjols Triassic uplift. Keywords: Paleocene Early Ypresian Rupelian „Sables bleutés du Haut Var‟ Formation Carbonate microfaciesAccepted Manuscript Provence Pyrenean-Provence tectonics 1. Introduction Page 2 of 62 In Provence, the Paleogene is represented by continental deposits filling in graben and basinal areas (Fig. 1). The most widespread facies correspond to lacustrine, palustrine, fluviatile, and terrestrial environments (Cavelier et al., 1984; Durand and Nury, 1984). Paleogene deposits from Provence recorded significant climatic (Cojan and Moreau, 2006) and tectonic (Leleu, 2005; Leleu et al., 2009) events. During Paleocene, alluvial fans derived from the incipient Basse-Provence E-W trending tectonic structures (Lutaud, 1957) spread away into flood-plain areas. In the Basse-Provence region, the Pyrenean-Provence major compressive tectonic phase occurred during late Eocene times and was responsible for emplacement of the main overthrusts (Lacombe and Jolivet, 2005; Andreani et al., 2010; Espurt et al., 2012; Bestani et al., 2015). During the Oligocene, a distensive regime led to the opening of the main Manosque, Marseille and Aix-en-Provence grabens that were filled in either by coarse detritic or by carbonate and evaporitic facies (Gigot et al., 1977; Hippolyte et al., 1991). In the Aix-en-Provence, Marseille and Manosque basins, the distinction between Paleocene, Eocene and Oligocene series has been the subject of a wide consensus (Cavelier et al., 1984; Durand and Nury, 1984) and correlations were established with the Languedoc (Alabouvette and Cavelier, 1984), the Pyrenean realm (Plaziat, 1984), and the southern Castellane subalpine grabens (Roux, 1974; Giannerini, 1980-1981). However, precisions are still required concerning the Paleogene stratigraphy of northeastern Provence (Haut Var regional area) that has been greatly debated (Ginsburg et al., 1967; Touraine, 1973a; Angelier and Aubouin, 1973; Durand, 1984; Philip, 2012, 2013; Plaziat, 2013a, 2013b). A clarification of this regional stratigraphy is needed for a better understanding of tectonic and paleogeographical questions, as well as for establishing correlations with other Paleogene basins. Likewise, clarification is also required concerning the respective age range of some fossil groups used as biomarkers in the Haut Var Paleogene continental facies, mainly gastropods (Lapparent, 1938a; Rey, 1966) vs. mammals (Ginsburg et al., 1967; Godinot, 1981). The aim ofAccepted this paper is to revisit the Paleogene Manuscript stratigraphy of the Haut Var area and to shed light on the age of the conspicuous but controversial „Sables bleutés du Haut Var‟ Formation. Hence, the new stratigraphical framework will lead to provide a better reconstruction of the paleoenvironmental and paleogeographical evolution of this area during the Paleogene and will contribute to highlight new perspectives for more accurate correlations with other Paleogene Provence and west European basins. Page 3 of 62 2. Geological setting and historical background The Haut Var region represents the northern part of the French Var department, including the Barjols, Tavernes, Rians, Salernes and Aups administrative cantons (Fig. 1: insert). It appears as an intermediate geological domain located between the Basse-Provence fold and north verging thrust systems to the south, and the Alpine fold and south verging thrust front to the north. In the Haut Var area, the Paleogene extends in synclines and grabens bounded by normal faults or thrusts (Fig. 2). Paleogene strata overlie either conformably the Maastrichtian (Rognacian