Serge Ferry
email: serge.ferry@yahoo.fr

Summary on Mesozoic carbonate deposits of the Vocontian Trough (Subalpine Chains, SE France)

Keywords:

led by Bruno Granier (University of Brest, France) on behalf of the Groupe Français du Crétacé (French Group for the Cretaceous). It focusses on : --1) a description of the gravity--reworked carbonates (calcarenites and breccias) around the Jurassic--Cretaceous boundary, and in the Barremian to Albian deposits in the central Vocontian Trough.

--2) a brief discussion on the local expression of the "Austrian" tectonic phase around the Aptian--Albian boundary.

--3) the local context of the Cretaceous so--called Ocean Anoxic Events (OAEs), with their black shales also present in the VT, in the light of recent research.

Introduction

In the southern subalpine chains (Fig. 1), the Vocontian Trough VT [START_REF] Paquier | Recherches géologiques dans le Diois et les Baronnies orientales[END_REF]) is a W-E oriented paleogeographic feature slowly born in the Early Cretaceous through a contraction of a larger Liassic to Late Jurassic basin (Fig. 2). The Vocontian Trough proper is located between the Ver-cors Plateau to the north and the Ventoux-Lure chain to the south. It covers the Diois and Baronnies regions. In the literature, the basinal area of the southeastern subalpine chains (Digne thrust and tectonic arc of Castellane) is often included in a Vocontian domain lato sensu. (after FERRY & GROSHENY, 2013). Barremian: orange, max. extension of Urgonian platformal carbonates; green, slope limestones; blue, basinal limestone-marl alternation; red, carcarenite turbidites lobes. Cenomanian: black-lined yellow, sand spit bordering a back-barrier lignite lagoon, blue, basinal limestones and marlstones, dotted lines, residual basin after the forced regression of the C-T boundary on the western margin, and location of the black shales in the restricted basin; the forced regression is strong on the Rhodanian saddle, mild or non existent in the eastern part of the basin. Turonian: solid lines, paleogeography around the upper lower to mid Turonian, yellow line, max. progradation of upper Turonian deltaic sandstones in the Rhodanian saddle; p, ramps folds born in the early Turonian, their heads being capped by shallow-water calcarenites. Coniacian: orange, shallow-water deposits (sandstones, calcarenites, rudist-bearing limestones); blue, basinal limestones; grey, calcarenite and conglomerate slope apron of Les Gâs; p, Chauvac fold (60° angular disconformity between transgressive Coniacian calcarenites and vertical basinal Turonian limestones). Campanian: blue, undiff. finegrained limestones, a turbiditic facies (« lauzes ») developped on the ancient Vercors platform now drowned; grey, conglomerate and calcarenite slope apron of Glandage; p, pre-Campanian folds of the Dévoluy; also note the northward shift of the Aix continental basin vs. the older south-Provence marine basin. On maps C to E, facies belts of the south-Provence basin are not detailed. (from FERRY & GROSHENY, 2013;after FERRY, 1978after FERRY, , 1979after FERRY, , 1984;;[START_REF] Ferry | Mégabrèches de resédimentation, lacunes mécaniques et pseudo -« hard-grounds » sur la marge vocontienne au Barrémien et à PAptien inférieur (Sud-Est de la France)[END_REF]. Black star, Crupies-L'Estellon area; dots, sections shown in the axial transect of Fig. 7.

The Vocontian Mesozoic sedimentary pile (Fig. 3) is exceptionnally thick (possibly approaching 10,000 m under the presentday middle Rhône valley), mainly through the thickness increase of Upper Liassic to Middle Jurassic deposits during peak Alpine extension. This raises the question of the geodynamic significance of such a narrow external basin, oriented roughly perpendicular to the Alps. Could it be a relay between the Biscay Gulf -Pyrenees system and a controversial Valais Ocean in the Alps, through the transform corridor of the Cevennes faults bordering the Massif Central, where accumulation rates are also very high? Evidences of submarine hydrothermalism in the Late Jurassic [START_REF] Rollin | Ecologie des pseudobiohermes des Terres Noires jurassiques liés à des paléo-sources sous-marines. Le site oxfordien de Beauvoisin(Drôme, Bassin du Sud-Est, France)[END_REF]GAIL-LARD et al., 1992) and the Early Cretaceous [START_REF]-Biostratigraphie des lentilles à peregrinelles (brachiopodes) de l'Hauterivien de Rottier (Drôme, France)[END_REF][START_REF] Lemoine | -Indices possibles de paléohydrothermalisme sous-marin dans le Jurassique et le Crétacé des Alpes occidentales (océan téthysien et sa marge continentale européenne) : essai d'inventaire[END_REF] could support the hypothesis of an aborted rift segment between the two oceans, but the closure of the Alpine Ocean in the Late Cretaceous has left too few remains in front of the thrusted belt to fully understand the early paleogeography of its French western border. In addition, an unsolved problem remains: the original location of some « Alpine zones » such as the Briançonnais that could be exotic southern terranes, now pushed to the west in front of the frontal thrust, after a S->N early move in the Late Cretaceous [START_REF] Ricou | Sub-briançonnais; un ample décrochement sénestre subméridien[END_REF][START_REF] Ricou | Les Alpes occidentales : chaine de décrochement[END_REF], and therefore fully obliterating the above early paleogeographic connections.

Post-Variscan extension began in the Triassic [START_REF] Baudrimont | Un bassin mésogéen du domaine péri-alpin : le Sud-Est de la France[END_REF] with the development of an evaporite basin, probably limited to the east by swells corresponding to the the present-day External Crystalline Massifs (MCE, Fig. 1). Subsidence incrased dramatically in the Liassic and the middle Jurassic (Fig. 4) with the deposition of very thick successions dominated by dark marlstones (Terres Noires Fm.) alternating with bundles of alternating lime mudstone and marlstone beds (Fig. 3). Conversely, the scarcity of gravity reworkings, except for thin-bedded turbidites at some stratigraphic levels, is evidence of a limited depositional depth. Redeposited carbonates (mostly slumps deposits) appear in the Oxfordian (Fig. 3) to reach a first maximum in the Tithonian with the extensive but short-lived development of breccias. The development of these carbonate-gravity reworkings is indirect evidence of the beginning of the formation of the VT proper (narrowing of the basin, increasing depositional depth).

Fig. 7. Correlation of the Barremian to lower

Aptian successions across the Vocontian Trough. CL1 to CL3, GBsc, GHsBi, main debris flow beds identified (see [START_REF] Ferry | Mégabrèches de resédimentation, lacunes mécaniques et pseudo -« hard-grounds » sur la marge vocontienne au Barrémien et à PAptien inférieur (Sud-Est de la France)[END_REF], FERRY, 1987). VH, Heteroceras marls; VM, thin recessive marly interval in the middle part of the limestone package under the VH; BS, black shale. BO1b, « barre à orbitolines » (see Fig. 18). The Tithonian breccias have been interpreted in different ways since the end of the 19th century, but they are now acknowledged as coming from the gravity-reworking of mostly slope mudstones [START_REF] Remane | Les formations bréchiques dans le Tithonique du Sud-Est de la France[END_REF][START_REF] Remane | Die Enststehung der resédimentaren Breccien im Obertithon der subalpinen Ketten Frankreichs[END_REF][START_REF] Beaudoin | Méthodes d'analyse sédimentaire et reconstitution du bassin : le Jurassique terminal-Berriasien des chaînes subalpines méridionales[END_REF][START_REF] Beaudoin | -Vallées sous-marines et systèmes d'épandages carbonatés du Berriasien vocontien (Alpes méridionales françaises)[END_REF]. Recent studies [START_REF] Courjault | -Detailed anatomy of a deep-water carbonate breccia lobe (Upper Jurassic, French subalpine basin)[END_REF]FER-RY & GROSHENY, 2013;[START_REF] Ferry | The base-of-slope carbonate breccia system of Céüse (Tithonian, S-E France): occurrence of progradational stratification in the head plug of coarse granular flow deposits[END_REF] have suggested that the breccias did not fill submarine canyons (absence of onlaps against the supposed walls, lateral deposits actually onlapping the main breccia bodies and not the contrary that would be expected in the canyon interpretation) as proposed earlier (REMANE, 1966;[START_REF] Beaudoin | Méthodes d'analyse sédimentaire et reconstitution du bassin : le Jurassique terminal-Berriasien des chaînes subalpines méridionales[END_REF]JO-SEPH et al., 1988). They instead accumulated as lobes in slight positive relief on the sea bottom (Fig. 5). The style of gravity-reworked deposits changed in the « Neocomian » (late Berriasian to Hauterivian) to being almost exclusively of the slump type, bearing only contorted beds (Fig. 3). The quick progradation of Urgonian platformal carbonates in the Barremian-early Aptian allows identification of the boundary of the Vocontian Trough proper (VT), as early defined by PAQUIER. During this time interval, a second burst of gravity reworkings occurred (Fig. 3), with calcarenite turbidite lobes developping in the basin (Fig. 6), together with thick debris flow beds or masstransport deposits (MTDs) able to carry large undeformed blocks, hundred metres long and several tens of metres thick of slope carbonates over more than tens of kilometres [START_REF] Ferry | Mégabrèches de resédimentation, lacunes mécaniques et pseudo -« hard-grounds » sur la marge vocontienne au Barrémien et à PAptien inférieur (Sud-Est de la France)[END_REF]. After the demise of Urgonian carbonate platforms in the late early Aptian (late Bedoulian), of ill-understood causes (? climate change, transgression, both), the basinal sedimentation changed to monotonous marlstones (Blue Marls Fm.) hosting sandstone packages, early known as « grès sus-aptiens ». These sandstones can be massive and structureless but their association with classical graded turbidite beds led to their interpretation as some kind of mass flow deposits. They are best developped west of the N-S Saillans-Condorcet fault (Fig. 1), in Pays de Bourdeaux. In the centre of the Vocontian Trough (Arnayon, La Charce, Rosans), they are almost absent in Albian deposits, only developped in Aptian ones. Present knowledge of Aptian sandstones have been summarized in a paper by (2003). For Albian sandstones, see [START_REF] Ferry | Mesozoic Eustacy Record on Western Tethyan Margins. Post-meeting field-trip in the Vocontian Trough[END_REF]. Stratigraphic information on the Blue Marls Fm. at the basin scale, as well as on black shales can be found in BRÉHÉRET (1995). The problem of the Albian (changing paleogeography, relationship with the PAQUIER black shale) will be discussed further in this document.

FRIES & PARIZE ##############################
Ongoing research (FERRY and coll.) brings a great deal of evidence that the progressive closure of the Vocontian Trough began around the Aptian-Albian boundary, that is during a tectonic phase known elsewhere as the « Austrian phase ». The closure continued in a stepped way up to the Santonian when the trough proper was completely filled with « deltaic sandstones » (POR-THAULT, 1974). The « pelagic » sedimentation then moved to the east (Digne-Castellane basin) (Fig. 2).

From Cenomanian times on, the depositional depth in the Vocontian Trough diminished (scarcity of gravity reworkings, shallower basinal limestone facies), probably as a consequence of the ongoing tectonic closure. However, the thickness of deposits (about 2,000 m of Cenomanian to Turonian limestones in the Meouge and the Pommerol synclines in the basin centre, according to [START_REF] Porthault | Le Crétacé supérieur de la "fosse vocontienne" et des régions limitrophes (France Sud-Est). Micropaléontologie, stratigraphie, paléogéographie[END_REF] clearly indicates uninterrupted strong subsidence. Evidences of ramp folds have been found (research in progress) in Turonian deposits in the western VT as a consequence of sinistral strike-slip movement of N40 oriented faults. Around the Turonian-Coniacian boundary in the central VT, local angular disconformities reaching 60° have been found. These results confirm the earlier feelings of FLAN-DRIN (1966) on late Cretaceous S-N compressive tectonics in the VT, prior to the Eocene « Pyrenean phase ».

More information about Vocontian

Mesozoic carbonate gravity reworkings, including bibliographic references, can be found in [START_REF] Ferry | Turbidites et brèches carbonatées. Jurassique et Crétacé du bassin subalpin. Livret-Guide Excursion du Groupe Français du Crétacé[END_REF].

The monotonous limestone-marl alternation that characterises the VT succession from the Liassic to the Turonian is therefore more or less impacted by the gravity-reworked deposits. An example is given for Barremian-lower Aptien deposits (Fig. 7). In intervals devoid of slump deposits, early studies Fig. 9. The Veynes section (from [START_REF] Courjault | -Detailed anatomy of a deep-water carbonate breccia lobe (Upper Jurassic, French subalpine basin)[END_REF], after ATROPS in BACKERT, 2004). Blue, breccia beds; pink, calcarenite beds. P, M, Ponti and Microcanthum ammonite zones. The Calcaires Blancs is a limestone-dominated Formation defined on the western border of the Subalpine Basin (Ardèche area) but which can be traced in some basinal areas when gravity reworkings are scarcer. The Tithonian-Berriasian boundary as defined by the boundary between the A and B calpionellids zones is within it. The change to a marl-limestone alternation is around the base of the Grandis ammonite Zone.

studies [START_REF] Cotillon | -Fluctuations des paramètres du milieu marin dans le domaine vocontien (France Sud-Est) au Crétacé inférieur: mise en évidence par l'étude des formations marno-calcaires alternantes[END_REF] have shown that individual beds can be traced all over the deep-water area without changes in thickness (Fig. 8). This was later used to map in a very precise way the areal changes in clay mineral assemblages [START_REF] Ferry | Diagenèse croissante des argiles dans des niveaux isochrones de l'alternance valanginienne du bassin vocontien[END_REF][START_REF] Levert | Diagenèse argileuse complexe dans le Mésozoique subalpin révélée par cartographie des proportions relatives d'argiles selon des niveaux isochrones[END_REF] and to propose interpretations deciphering areal depositional changes vs. diagenetic changes. In slope deposits, FERRY & MONIER (1987) showed that the individual basinal beds can expand into bundles of hemipelagic beds up to 15 to, 20 times thicker, but the rule is not strict. In a general way, high-resolution correlations become difficult or impossible when approaching slope successions, although the main limestone packages in third-order depositional sequences can be traced from basinal successions to platform carbonates proper.

The climatic significance of the bed-scale basinal limestone-marl alternation was first suggested by [START_REF] Cotillon | -Fluctuations des paramètres du milieu marin dans le domaine vocontien (France Sud-Est) au Crétacé inférieur: mise en évidence par l'étude des formations marno-calcaires alternantes[END_REF]. Changes in mineralogical and faunal changes (ratio of pelagic organisms) between limestone beds and marlstone interbeds [START_REF] Darmedru | Rythmes climatiques et biologiques en milieu marin pelagique; Leur relation dans les dépôts crétaces alternants du Bassin Vocontien (SE France)[END_REF] indicated environmental changes possibly under astronomical control due to frequencies close to those of the terrestrial orbit [START_REF] Rio | -Rhythmic pelagic successions and terrestrial orbital variations. The example of the Lower Cretaceous from Angles (SE France)[END_REF], following the MILANLOVITCH theory of climate changes in the Quaternary. Later, the development of FOURRIER transform analysis on such limestone-marl successions led to the emergence of a way to calibrate geological time [START_REF] Boulila | Orbital calibration of the Early Kimmeridgian (southeastern France): implications for geochronology and sequence stratigraphy[END_REF][START_REF] Boulila | -Milankovitch and sub-Milankovitch forcing of the Oxfordian (Late Jurassic) Terres Noires Formation (SE France) and global implications[END_REF][START_REF] Charbonnier | Astronomical calibration of the Valanginian "Weissert" episode: The Orpierre marl-limestone succession (Vocontian Basin, southeastern France)[END_REF][START_REF] Martinez | Astrochronology of the Valanginian Stage from reference sections (Vocontian Basin, France) and palaeoenvironmental implications for the Weissert Event[END_REF]. In this respect, the VT is a good candidate, given that most of its Jurassic to Lower Cretaceous stratigraphic column pre-sents this primary alternating pattern. In the Terres Noires and Blue Marls formations, subtle changes in gray shades are the subdued expression of that alternating pattern.

The following developments will mainly focus on:

1) a description of the gravity-reworked carbonates (calcarenites and breccias) around the Jurassic-Cretaceous boundary, and in the Barremian to Albian deposits in the central Vocontian Trough;

2) a brief discussion on the local expression of the « Austrian » tectonic phase around the Aptian-Albian boundary;

3) the local context of the Cretaceous socalled Ocean Anoxic Events (OAEs), with their black shales also present in the VT, in the light of recent research.

Uppermost Jurassic to Berriasian breccias in the Central Vocontian Trough and the regional problem of the Tithonian-Berriasian boundary

The huge development of breccias in the Tithonian, and the last widespread massive reworked intervals (Mass Transport Deposits, or MTDs) in the early Berriasian leaves no candidate section for accurately defining the Tithonian-Berriasian boundary in the Vocontian Trough proper. A possible section could be the Veynes section (Fig. 9) located in the eastern part of the basin where breccia beds are few, and restricted to the lower Tithonian. Comments on the depositional system and facies, especially in the Remuzat-Arnayon-Chalancon-La Charce area, as seen during the field trip, now follow.

The stratigraphic position of the breccia beds in the Drome river lobe (lobe A, Fig. 5) is given on Figure 10. Such a scheme is also roughly found in the other systems, according to [START_REF] Courjault | Brèches gravitaires sous-marines du Tithonien subalpin (S-E France)[END_REF]. Breccias are mostly occuring in the lower Tithonian, but late events may rework lower Tithonian breccias up into the lower Berriasian. This is the case in the upper mega-slump (Fig. 10) which is sealed by lower Berriasian mudstones (age of its emplacement) but carry lower Tithonian ammonites. There are other evidences of multiple reworkings like clasts of microbreccia matrix floating in mudsupported breccias. The reason why breccias were most commonly emplaced during the early Tithonian probably comes from the original pattern of the slope to basinal mudstones deposited at that time. In basinal areas insulated from the reworkings, unlike the pattern of the common bed-scale limesto-ne-marl alternation, uppermost Kimmeridgian to lower Tithonian deposits bear a nodular or very finely bedded pattern whose disrupted slabs are often found in the breccias. So, the disruption of the bottom sediments in the initial slumps, progressively transformed into breccia during the downslope travel, was probably made easier, due to the original nodular pattern of the deposits. The material carried in the breccia beds are mostly lime mudstones (slope to basinal). When the travel distance increased, the clast size diminished to the calcarenite size. This is the case of the Aygues river calcarenite lobe (lobe B, Fig. 5) in which calcarenite beds contain very few platformal debris but do contain pellet-size lime mudstone clasts. It probably originated farther south and travelled along a canyon oriented close to the path of the present-day Nîmes fault (Fig. 1). Lobes C and D (Fig. 5), bearing classical breccias and slumps, probably originated on a deep-water talus located along the Ventoux-Lure chain, with a shorter travelling range. Figure 11 displays some typical facies. Calcarenite beds are mostly graded and often show BOUMA-type sequences, classical in turbidite deposits. Breccia beds are commonly massive and ungraded but their top may bear a graded top-turbidite bed going up from microbreccia to mudstone, either progressiveley or with a grain size break between the calcarenite and the mudstone material. The internal geometry of the head of the breccia beds may show progradational features, like in the tiny Céüse lobe (lobe E, Fig. 5) [START_REF] Ferry | The base-of-slope carbonate breccia system of Céüse (Tithonian, S-E France): occurrence of progradational stratification in the head plug of coarse granular flow deposits[END_REF]. The finding of HCS-like features in some beds has been at the origin of a recent controversy (BOUCHET-TE et al., 2001;[START_REF] Seguret | Storm deposits and storm-generated coarse carbonate breccias on a pelagic outer shelf (South-East Basin, France)[END_REF] about the mechanisms of emplacement of the breccias and therefore the actual depth of the basin (see discussion in [START_REF] Ferry | The base-of-slope carbonate breccia system of Céüse (Tithonian, S-E France): occurrence of progradational stratification in the head plug of coarse granular flow deposits[END_REF]. The field trip will mostly be in the Arnayon-La Charce area, in an axial position of the Vocontian Trough. This area is at the junction between two gravity systems (Fig. 12), that of the Aygues river lobe coming from the south, finishing against the right flank of the Drome river lobe coming from the NW.

The lobe of the Aygues river is mostly calcarenitic on a grain size point of view (very few bioclasts, mostly pellet-size lime mudstone clasts). It is made of two units separated by a key breccia bed in the middle of the cliff in the Aygues river gorge (Fig 11D and 13). This key bed is found within the Drôme river lobe at Chalancon. It allows to make stratigraphic correspondences with the NW breccia system (Fig. 16). The lobe is made of laterally-continuous, graded calcarenite beds probably making a draping system, in very low relief on the sea bottom (Fig. 14). The materials of the Drôme river lobe are mostly made of breccias, overlain by the upper mega-slump of COURJAULT (Fig. 5-2) which carryies large olistoliths (Fig. 11C).

These deposits can be seen in the sections of Arnayon (Fig. 15), Chalancon (Fig. 16) and La Charce (Fig. 17). See locations of these sections on Figure 12.

Barremian-Aptian calcarenites and mass-transport deposits

The quick progradation of platformal urgonian carbonates in the early Barremian was accompanied by a second burst of gravityreworked deposits in the Vocontian Trough proper. The resedimented material came from the three peripheral platforms (Fig. 6), the Vercors to the north, the Bas-Vivarais (« Ardèche ») to the west, and, a little later (latest Barremian), the north Provence on the southern margin of the Trough. The installment of shallow-water carbonates was early (earliest Barremian) on the Bas-Vivarais platform [START_REF] Cotillon | Synthèse stratigraphique et paléogéographique sur les faciès urgoniens du Sud de l'Ardèche et du Nord du Gard (France S-E)[END_REF]GRA-NIER et al., 2013a). All lower Barremian resedimented calcarenites in the Vocontian Trough come from the Bas-Vivarais platform. The other sources operated in the late Barremian. Calcarenite turbidites disappeared just before the Barremian-Aptian boundary. The stratigraphic position of the main calcarenite bursts in the basin are on Figure 18. Debris-flow beds --that are beds carrying debris of all sizes within a supporting matrix --appeared in the lowermost Barremian (GHsBi) and finished at the base of the upper Aptian (CL4). In the Blue Marls Fm. it is more difficult to make the difference bet-ween debris flow beds and slump beds (see synthesis of [START_REF] Fries | Anatomy of ancient passive margin slope systems: Aptian gravity-driven deposition on the Vocontian palaeomargin, western Alps, south-east France[END_REF]. Slump beds (comprising only contorted beds, no. matrix) are frequent (not indicated on Figure 18, except for the largest like Gbis and GBsc). Debris flow beds covered large areas in the Vocontian Trough. They can be easily traced (Fig. 7). For instance, CL3 (Fig. 19) removed about 6 km 3 of deposits [START_REF] Ferry | Mégabrèches de resédimentation, lacunes mécaniques et pseudo -« hard-grounds » sur la marge vocontienne au Barrémien et à PAptien inférieur (Sud-Est de la France)[END_REF], and GHsBi probably twice that volume [START_REF] Ferry | Eustatisme et séquences de dépôt dans le Crétacé du Sud-Est de la France. Livret-guide excursion du Groupe Français du Cétacé en fosse vocontienne 25)27 mai 1988)[END_REF].

Autochtonous mudstones are of two main types, slope and basinal. Slope mudstones often have a macronodular pattern (they are called « faciès à miches or « loafy » limestones) (Fig. 19-B). When very thick (high subsidence rate) they are organized into bed bundles (Fig. 19-A). Basinal limestone-marl alternations (Fig. , 19-C) are thinner, and individual beds are laterally-continuous over the whole basin (Fig. 8). Slope mudstones show large channels (Fig. 19-D) that are supposed to have been the conduits funnelling the calcareous periplatformal sands to the deep. On figure, 20 are some facies of Barremian calcarenite turbidites. The Crupies section shows interesting turbidite sequences within the « Barre à Orbitolines » (Fig. 23). Diverse forms of grading in the overlying calcarenite packages can be observed along the road. Time permitting, the first sandstone turbidite package in the lower part of the Blue Marls Fm. can be seen a bit farther towards the Bourdeaux village (Fig. 24). It is an amalgamation of turbidite channels affected by large scale loadcasting.

Paleogeographic changes in the midle Rhône Valley and the western Vocontian Trough in the Aptian-Turonian interval

The exploration work of the French Agency for Nuclear Waste (ANDRA) in the middle Rhône valley (Gard Rhodanien) in the nineties allowed better understanding of the stratigraphy of the western margin of the Vocontian Trough (FERRY, 1999), now hidden by Cenozoic Molasse deposits. It particularly showed that the middle Rhône valley, as part of the Alpine margin, did not subside steadily but recorded episodic uplifts. A stong one occurred in the latest Aptian, and spanned locally the whole Albian. This event is time equivalent to the uplift of the Durancian Isthmus on the north Provence platform [START_REF] Philip | Paleogéographie et tectonique du Crétacé moyen en Provence : révision du concept d'isthme durancien[END_REF]. The Albian represents a stratigraphic interval which is hard to understand. Contrary to earlier deposits that show a regular thinning toward the western margin, Albian sandstones are lacking in the Middle Rhône valley (Fig. 25). This has been interpreted [START_REF] Ferry | Apports des forages ANDRA de Marcoule à la connaissance de la marge crétacée rhodanienne[END_REF] as a result of an uplift coeval with the one known as Durancian Isthmus [START_REF] Philip | Paleogéographie et tectonique du Crétacé moyen en Provence : révision du concept d'isthme durancien[END_REF] on the north Provence platform. In the Gard Rhodanian area, upper Albian megarippled sandstones are known west of the uplifted area. They rest on Gargasian deposits through a transgressive lag bearing lower to middle Albian ammonites. They are overlain by the uppermost Albian (Vraconnian) transgressive sandy marlstones (BREISTROFFER, 1940). Albian megarippled sandstones are shifted seaward north of the middle Rhône valley swell to make a marginal wedge (Fig. 25, lower box) that stretches to the north following the path of N40 oriented faults. The exact age of the Albian sandstones of La lance (Fig. 25) is not known. There is a curious relationship found by [START_REF] Ferry | Mesozoic Eustacy Record on Western Tethyan Margins. Post-meeting field-trip in the Vocontian Trough[END_REF] between the megarippled sandstones and the massive sandstones interpreted as turbidites in the Vocontian Trough (G4 to G6 turbidite packages at Vesc, Valouse, Fig. 25). Massive channelled sandstones, interpreted as turbidites, pinch out within the megarippled sandstones along La lance anticline. Based on its turbidite interpretation, RUBINO interpreted the megarippled sandstones as outer shelf sands deposited by a large contour current. But the discovery of strong stratigraphic hiatuses in the western part of the Vocontian Trough where the turbidite packages are developped raises a lot of questions. In a number of sections, Vraconnian marls rest directly on Clansayesian or (?) lower Albian marls. The turbidite sandstones G4 to G6 seems to be channelled in a narrow corridor north of the Dieulefit syncline. In addition, they quickly thin to the east when approaching the Saillans-Condorcet fault (SCF, Fig. 25). The paleogeographic picture that is emerging under the light of new field work is that of a shallow marine terrrace that was the conduit for the Albian « turbidites » north of the La Lance anticline. It is even possible that the margins of this terrace underwent prolonged exposures to explain the stratigraphic hiatuses found. A strong paleogeographic change therefore occurred, beginning around the Aptian-Albian boundary, after the deposition of the thick (250-300m) Aptian marls. The peak of the overall shallowing trend is not dated. It could be middle Albian in age. The Albian must therefore be considered as overall regressive on the middle Rhône valley and the westen Vocontian Trough. East of the Saillans-Condorcet fault, Albian marls are thick. They bear the black shale levels named by BRÉHÉRET (1988BRÉHÉRET ( , 1995) ) In the latest Albian (Vraconnian), a major transgression occurred over the whole S-E France basin. It was accompanied in the Gard Rhodanian by a spectacular reversal of the subsidence rate, with the thick Marcoule Silty Claystones deposited on the previous middle Rhône valley swell (Fig. 25). Its full submergence occurred in the late Vraconnian or locally the early Cenomanian.

Another event occurred in the earliest Cenomanian. The Orbitolina sandstones (GO1 and GO2, Fig. 25) represent two shortlived progradational phases of swell-dominated glauconitic sandstones, each finishing with a beach facies [START_REF] Ferry | Apports des forages ANDRA de Marcoule à la connaissance de la marge crétacée rhodanienne[END_REF]. They pass seaward to a double package of bedded sandy limestones (F1 and F2, Fig. 25). These reach a maximun thickness in the Fig. 25. Stratigraphic transect across the western margin of the Vocontian Trough (Aptian to middle Cenomanian). Stages (in ascending order): lBd, lower Bedoulian; uBd, upper Bedoulian (cycle comprising the black shale GOGUEL); lGa, lower Gargasian; uGa, upper Gargasian; CL, Clansayesian (uppermost Aptian); Ab, Albian (Vraconnian excluded); Vr, Vraconnian (uppermost Albian); lmCe, lowermost Cenomanian; lCe, lower Cenomanian; mCe, middle Cenomanian; uCe, upper Cenomanian. Background colours: 1, Barremian to lower Aptian slope to basin limestones; 2, uppermost lower Aptian to Clansayesian deposits; 3, Albian (Vraconnian excluded); 4, Vraconnian major transgressive cycle; 5, Cenomanian slope to basin limestones and marlstones; 6, sandstones undifferenciated; 7, direction of transport (Albian turbidites). Sedimentary units: chs, channelled sandstone; GD, « Grès à Discoidea » (Discoidea sandstone) [START_REF] Conte | Découverte d'ammonites du Gargasien dans les "grès et calcaires à discoïdes et orbitolines" du synclinal de la Tave[END_REF]; GO1 and GO2, « Grès à orbitolines » (Orbitolina-bearing sst.); F1 and F2, bundles of sandy slope limestone corresponding to, respectively, GO1 and GO2; G1 to G6, packages of sandstone turbidites defined by [START_REF] Ferry | Eustatisme et séquences de dépôt dans le Crétacé du Sud-Est de la France. Livret-guide excursion du Groupe Français du Cétacé en fosse vocontienne 25)27 mai 1988)[END_REF][START_REF]Crise anoxique à la limite Cénomanien-Turonien dans le bassin subalpin oriental (Sud-Est de la France). Relation avec l'eustatisme[END_REF]; SSRV, Cenomanian sandstone spit of the middle Rhône Valley, on the margin of a backbarrier lignite lagoon. Black shales: BsG, GOGUEL; BsJ, JACOB; BsK, KILIAN; BsP, PAQUIER; BsB, BREISTROFFER. mCeRF, mid-Cenomanian forced regression; SCF, Saillans-Condorcet fault (FLAN- DRIN & WEBER, 1966). Albian-Cenomanian boundary in the MAR wells according to AMÉDRO & ROBASZINSKY (2000).

La Lance anticline where they are channelled. In the axial position of the channel, a sandstone bed, up to 10 m thick is found. This double bed package progressively thins basinward without any evidence of erosion at the base. However, in the Valouse area, close to the Saillans-Condorcet fault, the lower Cenomanian basinal limestones rest unconformably on the thinned distal G5-G6 Albian turbidite sandstones (Fig. 25). Again, this is interpreted as a new movement of the Saillans-Condorcet fault. The lowermost Cenomanian GO1-GO2 interval is therefore coincidental with a flexuration of the La Lance anticline and an uplift of the eastern boundary of the upper terrace defined in the Albian. This is interesting from a sequence stratigraphic point of view. In the Gard area (MAR wells) the Vraconnian to lowermost Cenomanian deposits are arranged in a shallowing-up trend, without any evidence of a sequence boundary close to the Albian-Cenomanian boundary. In the La Lance section, the erosive base of the F1-F2 limestone packages could be called a sequence boundary. Basinward, again, there are no evidence of any facies break. But at Valouse, there is clearly a sequence boundary at base of the Cenomanian deposits. This example is particularly demonstrative of how tectonics may alter a possible eustatic sea-level signal, if such exists.

Another event is known in the mid-Cenomanian. From the sandstone spit that fringed the lignite lagoon during the lower Cenomanian, a strong seawardshift of megarippled coastal sandstones is recorded in La Lance anticline (Fig. 25).

The Cenomanian-Turonian boundary is also marked by a strong uplift of the western margin of the Vocontian Trough that is responsible for a forced regression that shifted the coastal sandstones seaward about 80 km to the east [START_REF] Malartre | Régression forcée à la limite Cénomanien/Turonien dans le bassin subalpin (S-E de la France)[END_REF][START_REF] Grosheny | -Record of the Cenomanian-Turonian Boundary Event (CTBE) on the southern slope of the Subalpine Basin (SE France) and its significance on a larger scale[END_REF] (see also Fig. 2C). This summary of the behaviour of the western margin of the Vocontian Trough (the Rhodanian Saddle of [START_REF] Porthault | Le Crétacé supérieur de la "fosse vocontienne" et des régions limitrophes (France Sud-Est). Micropaléontologie, stratigraphie, paléogéographie[END_REF] during the Cretaceous clearly shows that it was a tectonically unstable margin, subjected to short-lived uplifts or accelerated subsidences which clearly begin in the Albian.

Cretaceous Ocean Anoxic Events (OAEs) in their local sequence stratigraphic context

Of the many black shale events recorded in the Vocontian Trough, only three are addressed here: the late early Aptian OAE1a, the early Albian OAE1b, and the latest Cenomanian OAE2. In the Vocontian Trough, they have been named, respectively, the « GOGUEL », « PAQUIER » and « THOMEL » levels (BRÉHÉRET, 1988;CRUMIÈRE, 1989). The purpose of the following text is is not to discuss their origin. This has been addressed by a huge volume of international literature over the last decades, VT included, especially on the PAQUIER level. Rather, it is to give a precise definition of their comparative sequence stratigraphic and paleogeographic context at the scale of the French Alpine margin.

1) Late early Aptian OAE1a

This OAE is associated with a δ 13 C shift, first negative then positive, recognized on a large scale outside the VT. International literature discussing this event is growing. The positive isotope excursion is maximum in the upper part of the cycle, above the black shale level when present, and continues into the lower upper Aptian.

The OAE1a is represented in the central Vocontian Trough by the GOGUEL black shale (Fig. 25) which occurs within a thin marl-limestone cycle found in Vocontian Trough sections, when not removed by slumping. The lower marl of this cycle, including the GOGUEL black shale, is lacking in the Angles section (Fig. 18), probably due to slumping but it is present in the Vocontian Lesches-en-Diois syncline [START_REF] Moullade M | Correlation of biostratigraphic and stable isotope events in the Aptian historical stratotype of La Bédoule (southeast France)[END_REF](MOULLADE, , 1995;;[START_REF] Ghirardi | Multi-proxy orbital chronology in the aftermath of the Aptian Oceanic Anoxic Event 1a: Palaeoceanographic implications (Serre Chaitieu section, Vocontian Basin, SE France)[END_REF]. The upper limestone bed is known as the « Niveau Blanc » (White Level or White Beds of [START_REF] Fries | Anatomy of ancient passive margin slope systems: Aptian gravity-driven deposition on the Vocontian palaeomargin, western Alps, south-east France[END_REF]. It can be traced atop of the same marlstone interval (with some changes in thickness) in many Vocontian sections (when preserved from slumpings) to the western border of the Trough in the Gard Department area (Marcoule exploration wells of ANDRA, Fig. 25). This cycle begins at the very time when Barremian to lower Aptian Urgonian carbonate platforms surrounding the VT ceased to function due to drowning (Fig. 18). As the drowning was accompanied by tectonic disturbances and paleogeographic changes, this cycle may be lacking on the platforms (hiatus either by exposure or by condensation on drowned plateaus), or reduced in thickness, or very expanded depending on location (the south Provence basin, for instance, [START_REF] Moullade M | Correlation of biostratigraphic and stable isotope events in the Aptian historical stratotype of La Bédoule (southeast France)[END_REF][START_REF] Moullade | High-resolution integrated stratigraphy of the OAE1a and enclosing strata from core drillings in the Bedoulian stratotype (Roquefort-La Bédoule, SE France)[END_REF]. More details on the western border of the trough can be found in PICTET & DELANOY (2017). On the Vercors Plateau, this cycle is represented by the upper Orbitolina beds that correspond to the infilling of channels on top of the Urgonian platform at the beginning of its drowning (ARNAUD- VAN-NEAU & ARNAUD, 1970). A correlation scheme is given to illustrate the changes in thickness and facies of this cycle in S-E France, either in basinal settings (Fig. 26) or in platform ones (Fig. 27).

A reexamination of the ANDRA wells in the southeastern Paris Basin (Fig. 28) led to understanding the pattern of the late early Aptian transgression in the Paris Basin. In the SC101 well, the « Argiles à Plicatules », of late early Aptian age (Deshayesi and Bowerbanki ammonite zones) according to AMÉDRO & MATRION, 2004b) rest on a lateritic weathering profile affecting marine sandstones and claystones of Barremian age, based on ostracods [START_REF] Damotte R | Contribution à l'étude des ostracodes marins dans le Crétacé du Bassin de Paris[END_REF] and dinoflagellates [START_REF] Courtinat | Les kystes de dinoflagellés des Argiles Ostréennes du Bassin de Paris, France[END_REF]. The « Argiles à Plicatules » are sharply overlain (sequence boundary) by glauconitic sandstones of probable late Aptian age (Nutfieldensis ammonite Zone according to AMÉDRO & MATRION, 2004a, 2008), which are referred to here as upper Gargasian (uGa) (Fig. 25). This sandstone unit is the southern counterpart of the lower Greensand in southern England (AMÉDRO & MANIA, 1976). On the basis of plant remains, dinoflagellates and nannofossils, the « Argiles à Plicatules » correspond to a full transgressive-regressive cycle (Fig. 27). This cycle has an equivalent in south England, the Atherfield Clay (AC) overlain by the sandy limestone of the Hythe Beds (HB). Given its late early Aptian age [START_REF] Casey R | The stratigraphical paleontology of the Lower Greensand[END_REF], the couple AC/HB is the boreal equivalent of the marl limestone cycle in E France (Fig. 26).

The « Argiles ostréennes » (oyster-bearing claystones) under the weathering profile (Fig. 28) were dated Barremian on the basis of ostracods by [START_REF] Damotte R | Contribution à l'étude des ostracodes marins dans le Crétacé du Bassin de Paris[END_REF]. The stratigraphic assignement was later confirmed by [START_REF] Courtinat | Les kystes de dinoflagellés des Argiles Ostréennes du Bassin de Paris, France[END_REF] from dinocysts. However, a reexamination of the stratigraphic range of dinoflagellates in the Lower Cretaceous [START_REF] Monteil | Les dinokystes du Valanginien du bassin du sud-est[END_REF]LON-DEIX, 1990;[START_REF] Ogg | Dinoflagellate cysts of the Early Cretaceous North Atlantic Ocean[END_REF]…) showed that most of the species considered as Barremian were already present in the Valanginian or appeared in the lower Hauterivian. The Barremian age of the Argiles ostréennes thus remains based on ostracods. However, an age problem arises from the sequence stratigraphic approach. no. facies break was found between the lower Hauterivian Calcaires à Spatangues dated by ammonites and the Argiles ostréennes (Fig. 28), nor was any break found at their top. For this reason, the exact age of the Argiles ostréennes remains poorly established. It could by Hauterivian, not Barremian. On the other hand, [START_REF] Clavel | -Dating and progradation of the Urgonian limestone from the Swiss Jura to South-East France[END_REF][START_REF] Clavel | Mapping the rise and demise of Urgonian platforms (Late Hauterivian -Early Aptian) in southeastern France and the Swiss Jura[END_REF] showed that Urgonian platformal carbonates prograded from the late Hauterivian to the early Aptian from the Jura to the French Subalpine chains on the Alpine margin. Therefore, it is probable that the updip area (Burgundy swell, southern Paris Basin) may have been exposed from the late Hauterivian, explaining the lateritic profile found in the Andra site of the Departement de l'Aube (Fig. 28). The submergence came at the beginning of the upper Bedoulian cycle. On a large scale, the Argiles à Plicatules/Atherfield Clay therefore represent a very quick transgression after the demise of Urgonian platforms of the north Tethyan margin. The Burgundy swell was submerged, and the paleosols and/or Wealden deposits of the Anglo-Paris basin were suddenly flooded by marine claystone (Fig. 29).

All available data (Figs. 26-28) therefore point to a « flash » transgression at base of cycle uBd, accompanied by tectonic deformations coincidental with the demise of Urgonian carbonate platforms (Fig. 27). The GOGUEL black shale was clearly deposited in a transgressive setting.

2) Early Albian OAE1b

From the above discussion, the Albian interval is clearly a time of relative sea-level drop in the SE France basin. The uplift of the Rhodanian saddle, together with a severe shallowing of the upper Vocontian terrace, (Fig. 25) led to a narrowing of the deep area where is found the PAQUIER black shale. The change is severe enough to wonder if this black shale is the result of a large scale environmental event or if it is just the result of a short-lived confinement in a restricted basin.

The new sequence stratigraphic data are therefore in accordence with geochemical results of [START_REF] Heimhofer | Contrasting origins of Early Cretaceous black shales in the Vocontian basin: Evidence from palynological and calcareous nannofossil records[END_REF] and [START_REF] Okano | Depositional Environments Revealed From Biomarkers in Sediments Deposited During the Mid-Cretaceous Oceanic Anoxic Events (OAEs) in the Vocontian Basin (SE France)[END_REF]. The geochemical data suggested that the PAQUIER level was more influenced by riverine input than the GO-GUEL level, which bears an opposite « geochemical » transgressive signal. From the above, the enhanced riverine input these researchers found can be easily related to the regressive trend found on the Alpine margin, beginning around the Aptian-Albian boundary. This regressive trend is not found in the Paris Basin. In contrast, the Albian « Argiles à tégulines » are transgressive on the upper Aptian « Sables verts de l'Aube » through a veneer of phosphate nodules that contain ammonites of the basal Tardefurcata Zone (AMÉDRO & MATRION, 2007). These opposite trends suggest again a tectonic control of the changes in relative sea-level. In other words, a sequence boundary (relative sealevel fall) may correlate laterally to a transgression surface.

3) Latest Cenomanian OAE2

The Cenomanian-Turonian boundary (CTB) is marked by a triple crisis: (1) deposition of organic-rich shales in deep basins (Atlantic, Tethys, marginal basins like the Vocontian Trough) as a result of a supposedly global anoxic event (although data about anoxy in the Pacific Ocean are scarce), (2) a positive δ 13 C shift that has been recognized worldwide, and (3) a paleontological crisis through the temporary disappearance of keeled planktic foraminifers (replacement of rotaliporids by globotruncanids). The CTB event (CTBE), as defined by the isotope anomaly, is mostly latest Cenomanian in age according to the many recent studies on a worldwide scale. The recovery to average values is within the lowermost Turonian. Black shales are known to cover a larger stratigraphic range on a global scale, locally beginning in the lower Cenomanian (Venezuela, southern Moroccan Atlantic margin), and finishing more or less late in the Turonian, especially in marginal basins like those of the Saharan Atlas in Algeria [START_REF] Grosheny | -The Upper Cenomanian-Turonian (Upper Cretaceous) of the Saharan Atlas (Algeria)[END_REF]. Since the early work of [START_REF] Schlanger | Cretaceous oceanic anoxic events: causes and consequences[END_REF], analysis of the event has generated a huge amount of literature over the past decades seeking to understand its causes and mechanisms.

This OAE is represented by the THOMEL black shale (CRUMIÈRE, 1989) in the basinal area of the southeastern subalpine chains (Castellane tectonic arc). The black shale is also present in the La Charce syncline along the axis of the Vocontian Trough. A recent synthesis [START_REF] Grosheny | -Record of the Cenomanian-Turonian Boundary Event (CTBE) on the southern slope of the Subalpine Basin (SE France) and its significance on a larger scale[END_REF] has shown that the event is not accompanied by a transgression in the French Alps (Fig. 30). On the western margin (Rhodanian saddle and western Vocontian Trough), a forced regression reminiscent of that of the mid-Cenomanian (mCeRF, Fig. 25) occurred during the first half of the δ 13 C anomaly. The shift of the shoreline was stronger than the former. The Vocontian Trough narrowed dramatically (Fig. 2C). On the southeastern margin of the basin, a very strong increase of the subsidence rate during the second half of the isotope shift was followed by a forced progradation of the Turonian carbonate platform east of the Rouaine fault, as a result of a sinistral strike-slip movement on this fault. Work in progress shows that the upper Cenomanian rudist-bearing carbona-te platform bordering the south Provence basin underwent a forced progradation (sharp base of platformal carbonates) exactly beginning with the rise of the isotope shift. The platform was flooded in ealy Turonian times. All these events contrast with the relative stability found during the late Cenomanian that was a period of flooding over the whole S-E France basin, without any clear changes in relative sea-level. The early Turonian was a time of uniform transgression. Therefore, the disturbances found are exactly coincidental with the CTBE.

Other data (GROSHENY et al., submitted) support the idea that the tectonic pulse is global, given the heterogeneity of the sequence stratigraphic record that has been found to occur on a larger scale exactly during the event.

In SE France, the THOMEL black shale of the so-called OAE2 is not associated with a transgressive trend, as has been suggested by many authors from geochemical data acquired in deep basinal sections, but rather with a narrowing of the deep area, a probable shallowing of the residual basin, and maybe some restriction of the bottom waters, given that bottom life was not fully suppressed during the THOMEL black shale deposition [START_REF] Courtinat | Dorvilleids and arabellids (Annelida) as indicators of dysaerobic events in well-laminated non-bioturbated deposits of the French Mesozoic[END_REF][START_REF] Grosheny | La crise Cénomanien-Turonien : réponse comparée des assemblages de foraminifères benthiques de plate-forme carbonatée et de bassin dans le Su-Est de la France[END_REF].

In summary, of the three OAEs investigated in the subalpine basin, only one (OAE1a) exists within a real transgressive setting. The two others (OAE1b and OAE2) are clearly within local regressive setting. All three are closely associated with tectonic disturbances.

Fig. 1 .

 1 Fig. 1. The southeastern France basin. CF, Cevennes fault; DT, Digne thrust; NF, Nîmes fault; SCF, Saillans-Condorcet fault. MCE, external crystalline massifs.

Fig. 2 .

 2 Fig. 2. Paleogeographic history of the Vocontian Trough and nearby areas from the Late Jurassic to the Late Cretaceous (after FERRY & GROSHENY, 2013). Barremian: orange, max. extension of Urgonian platformal carbonates; green, slope limestones; blue, basinal limestone-marl alternation; red, carcarenite turbidites lobes. Cenomanian: black-lined yellow, sand spit bordering a back-barrier lignite lagoon, blue, basinal limestones and marlstones, dotted lines, residual basin after the forced regression of the C-T boundary on the western margin, and location of the black shales in the restricted basin; the forced regression is strong on the Rhodanian saddle, mild or non existent in the eastern part of the basin. Turonian: solid lines, paleogeography around the upper lower to mid Turonian, yellow line, max. progradation of upper Turonian deltaic sandstones in the Rhodanian saddle; p, ramps folds born in the early Turonian, their heads being capped by shallow-water calcarenites. Coniacian: orange, shallow-water deposits (sandstones, calcarenites, rudist-bearing limestones); blue, basinal limestones; grey, calcarenite and conglomerate slope apron of Les Gâs; p, Chauvac fold (60° angular disconformity between transgressive Coniacian calcarenites and vertical basinal Turonian limestones). Campanian: blue, undiff. finegrained limestones, a turbiditic facies (« lauzes ») developped on the ancient Vercors platform now drowned; grey, conglomerate and calcarenite slope apron of Glandage; p, pre-Campanian folds of the Dévoluy; also note the northward shift of the Aix continental basin vs. the older south-Provence marine basin. On maps C to E, facies belts of the south-Provence basin are not detailed.

Fig. 3 .

 3 Fig. 3. The Vocontian Mesozoic succession. Gravity reworked deposits: CT, calcarenite turbidites; ST, sandstone turbidites; DFB, debris flow beds (including large Mass Transport Deposits or MTDs); S, slump deposits; plr, thin-bedded turbidites. Mostly present in the VT proper. Tectonic events: 1 to 3, inferred from strong forced regressions on the Rhodanian Saddle (see text); 4, Turonian folding culminating in the latest Turonian; 5, pre-Campanian phase (folding, strong paleogeographic reorganization at the end of the Santonian, deep basin remaining only in the southeastern subalpine chains).

Fig. 4 .

 4 Fig. 4. NW-SE transect along the axis of the western part of the Vocontian Trough (based on exploration wells, completed with outcrops in the upper part of the successsions).

Fig. 5 .

 5 Fig. 5. Tithonian breccia lobes in the Vocontian Trough. 1, Location of the lobes (A to E); 2, Detail showing the convergence between the breccia lobe of the Drôme river (A) and the calcarenite lobe of the Aygues river (B) in the Arnayon-La Charce area. Also note the lateral shift to the right of the upper mega-slump vs. the axis of the lobe; 3, longitudinal (axial) section across the lobe; 4, transverse section across the distal part of the lobe showing deposition through avulsion and morphological compensation; breccia beds in blue, slump beds in yellow (after COUR-JAULT et al., 2011). Points of interest during the field trip in green (ARN, Arnayon; CLC, Chalencon; CRU, Crupies; EST, L'Estellon; LCH, La Charce; RMZ, Remuzat).

Fig. 6 .

 6 Fig. 6. Maximal areal extension of Barremian to lower Aptian calcarenite turbidite lobes in the Vocontian Trough (from FERRY & GROSHENY, 2013; after FERRY, 1978 after FERRY, , 1979 after FERRY, , 1984;;[START_REF] Ferry | Mégabrèches de resédimentation, lacunes mécaniques et pseudo -« hard-grounds » sur la marge vocontienne au Barrémien et à PAptien inférieur (Sud-Est de la France)[END_REF]. Black star, Crupies-L'Estellon area; dots, sections shown in the axial transect of Fig.7.

Fig. 8 .

 8 Fig. 8. The bed-scale limestone-marl alternation characteristic of the Mesozoic of the Vocontian Trough. A) Correlation between the upper Valanginian to lower Hauterivian bed bundles between the sections of La Charce (LCH) and Angles (ANG); red line, base of the Radiatus ammonite Zone (REBOULET & ATROPS, 1999). B) First attempt of bed by bed correlation in the limestone-marl alternation of the Vocontian Trough by COTILLON et al. (1980); the bed bundle is in the middle of the upper Valanginian. C) picture of the bed bundle correlated by COTIL-LON et al. (stratigraphic position in A, lower left). D) subdued alternation in the lower part (upper Aptian) of the Blue Marls Fm. (Reynier-Esparron, eastern subalpine basin).

Fig. 10 .

 10 Fig. 10. Stratigraphic position of the main gravity-reworked deposits in the Drôme Lobe(after COURJAULT et al., 2011, modified). Note that the Planula Zone is the last zone of the Oxfordian sensu gallico; CB, "Calcaires Blancs" Fm. Fig. 11. Facies of Tithonian deposits in the subalpine basin. A) View of the typical limestone-marl bed-scale alternation around the Oxfordian-Kimmeridgian boundary; B) Typical aspect of the « Tithonique cliff » auct. in the southern subalpine chains, in which thick beds are breccia beds; C and D) large blocks of undeformed mudstone carried in the « upper mega-slump » of COURJAULT et al. (2011) (Fig. 5); E) view of the mid-cliff key (…/…)

Fig. 13 .

 13 Fig. 13. The calcarenite lobe of the Aygues river. Above, view of the two calcarenite units M1 and M2, separated by the key breccia bed (kbb) in the Aygues river Gorge. Below, updip to downdip correlation across the lobe (location of sections in Fig. 12). Blue, breccia beds; pink, calcarenite beds; on left of lithologic columns are granulometric curves; CB, upper Tithonian to lowermost Berriasian « Calcaires Blancs » Fm.; red arrow, direction of transport.

Fig. 14 .

 14 Fig. 14. The Tithonian calcarenite lobe of the Aygues river near Remuzat. A, location of the view point; B, view of the Remuzat cliff about parallel to the direction of supplies (updip to the left); C, detail of the upper slump which is possibly a distant effect of the emplacement of the upper mega-slump of the Drôme lobe to the north. The lateral continuity of the beds is evidence of a draping system.

Fig. 15 .

 15 Fig. 15. Kimmeridgian to Tithonian succession of the Arnayon Gorge. (dated by ammonites, calpionellids, microfacies, after F. ATROPS, unpubl.).

Fig. 16 .

 16 Fig. 16. The Chalancon section.

Fig. 17 .

 17 Fig. 17. Tithonian breccias in La Charce section.

Fig. 18 .

 18 Fig. 18. Timing of deposition of the main Barremian to lower Aptian gravity reworkings in the Vocontian Trough against the limestone-marl succession of the Barremian hypostratotype of Angles. Based on ammonites and highresolution lithologic correlations (see Fig. 8); blue background, flooding facies of Urgonian platforms correlated with a quick transgression in the Paris Basin; pink background, main calcarenite supplies (turbidites) in the Vocontian Trough; BO, lower Barremian « barres à orbitolines » auct. (orbitolina-bearing calcarenite beds), stratigraphic position approximate; GHsBi to CL4, main debris flow beds. VH and VM, marly recessive intervals traced basinwide within the upper Barremian limestones (Fig. 7).

Fig, 19 .

 19 Fig, 19. Barremian deposits of the Vocontian Trough. A, thick upper Barremian slope mudstones made of bundles of nodular limestones (B); C, deep-water limestone-marl alternation; D, slope channel funneling the calcarenite turbidites in the Pays de Bourdeaux (E) (NW Vocontian Trough); F, debris-flow beds CL2 and CL3 in La Chaudière (CHD) section; E, map showing the areal extension of calcarenites turbidites in the Pays de Bourdeaux, and the debris flow beds coming from the Crest submarine canyon; underlined in violet is the large slump scar which fed the CL3 debris flow bed of La Chaudière (FERRY & FLANDRIN, 1979); The sections of Crupies (CRU) and L'Estellon (EST) seen during the field trip are indicated.

Fig. 20 .

 20 Fig. 20. Some facies of the Barremian calcarenite turbidites of the Vocontian Trough. A, typical appearance of a calcarenite turbidite package with internal erosional surfaces (current oblique from left background to right foreground; B and C, flute-casts of different sizes at base of graded (B) or coarse-tail graded (C) calcarenite beds; D, typical vertical organization of debris flow beds (a, highly deformed sole of basinal mudstones; b, main body, ungraded, floating clasts; d, associated top-turbidite bed with poorly-defined base (continuous deposition), E, example of D in the field.

Fig. 21 .

 21 Fig. 21. The Crupies (CRU) and L'Estellon (EST) sections. Crupies section from FERRY (1976) (see also MOULLADE, 1966), pink, main calcarenite beds; L'Estellon section from GRANIER et al. (2013a); BO1 an BO2, see Fig.18.

Fig. 22 .

 22 Fig. 22. Correlation of upper Barremian calcarenite turbidite packages (dotted) in the Pays de Bourdeaux (NW Vocontian Trough) and surrounding areas (FERRY, 1978). 1, Angles (simplified), see Fig 18; 2, Rochebaudin; 3, Felines; 4, Les Tonils, 5, Crupies; 6, Valouse; 7, L'Estellon; 8, Chaudebonne; 9, La Lance; 10, La Rochette (Nyons). Two sections will be visited during the field trip, the Crupies (CRU) and L'Estellon (EST) sections (Fig. 21). They are close to the eastern end of the lobes of the Pays de Bourdeaux. The Crupies section (Fig. 20) shows thick packages of calcarenite turbidites because, as in other places of the Pays de Bourdeaux (Fig. 22), supplies coming from the northwest (-> N150) and the west (-> N80) merged (Figs. 6 & 19-E). The L'Estellon section was recently studied by GRANIER et al. (2013a) to test the Orbitolina zonation used in the Vercors vs. the basinal sections better dated through ammonites

Fig. 23 .

 23 Fig. 23. The BO2 unit (or « barre à orbitolines » of MOULLADE, 1966) in the Crupies section. A, Detail of the unit showing event beds, some of them belonging to the debris flow bed case illustrated on Fig. 20-D-E; B, detail of the base with event beds numbered (see A) (from WALTER et al., 1975); C, debris-flow bed here reduced in thickness but with its associated calcarenite turbidite cap), note the poorly-defined transition from the mixture at base and the calcarenite at top; D and E, enlargement of the base of units 4 and 6 showing either calcarenite or marlstone clasts in the unsorted matrix. New stratigraphic data acquired in the western Vocontian Trough are combined with earlier results fron the ANDRA works. They allow drawing of a transect from the

Fig. 24 .

 24 Fig. 24. The lower sandstone turbidite body (mid-Gargasian) in the upper Aptian-Albian Blue Marls Fm. in the Crupies section. It consists of a package of channelled sandstones more or less disturbed by large load-casting. White arrow indicates the direction of transport. This turbidite unit is called G1 sandstones by RUBINO (in FERRY & RUBINO, 1989), or T1 sandstones by FRIES & PARIZE (2003). Correlation with deposits of the western margin (FER-RY, 1999) show that this event correspond to a strong relative sea-level fall.Above the Barremian to lower Aptian limestones, the upper Aptian to Albian Blue Marl Fm. thins to the west. In addition, Gargasian deposits clearly show two depositional sequences in the MAR wells. The lower Gargasian marls are dark marls, similar to those of the Vocontian Trough but a little more sandy. The thin upper Bedoulian sequence of Angles (Fig.18) is present (uBd, Fig.25) but without the GOGUEL black shale. An erosional unconformity bounds at base the second Gargasian sequence (uGa, Fig.25) the facies of which is a shallower bioturbated clayey sandstone. The basal unconformity is overlain with an echinoid-bearing bioclastic sandstone (Grès à Discoidea,[START_REF] Conte | Découverte d'ammonites du Gargasien dans les "grès et calcaires à discoïdes et orbitolines" du synclinal de la Tave[END_REF]. Small incised valleys have been found in the Gard Departement. This sequence boundary correlates in the Vocontian Trough with the base of the G1 turbidite sandstone[START_REF] Ferry | Mesozoic Eustacy Record on Western Tethyan Margins. Post-meeting field-trip in the Vocontian Trough[END_REF]), or T1 of FRIES & PARIZE (2003).

  (Fig. 25), which are absent west of the fault. The fault had clearly a synsedimentary role in limiting the deep Albian basin to the east (Fig. 25, lower box). It should be remembered that this fault involves the basement (FLANDRIN & WEBER, 1966) based on gravimetric data. It is hypo-thesized that the local tectonic disturbances during the Albian represent a first pulse in the transpressional trend that ended in the complete infilling of the Vocontian Trough in Santonian times.

Fig. 26 .

 26 Fig. 26. The upper Bedoulian sequence in basinal areas of S-E France. ANG, cf Fig. 18; SAR (FERRY, unpubl. data); LB, from MOULLADE et al. (1998), ROPOLO et al. (2006), LORENZEN et al. (2013), MOULLADE et al. (2015). NB, uppermost Bedoulian « White Bed » of FRIES & PARIZE (2003), T, thin-bedded turbidites, TOC, Total Organic Carbon.

Fig. 27 .

 27 Fig. 27. The upper Bedoulian sequence on platforms around the Vocontian Trough. Vercors from ARNAUD-VANNEAU & ARNAUD (1970); Ardèche Urgonian platform and slope from BUSNARDO in explanatory booklet of the geological map of Bourg-St-Andéol (1/50.000), also see PICTET & DELANOY (2017); MAR, 203 well from FERRY, 1999 (also see Fig. 25). uBd, upper Bedoulian; lGa, lower Gargasian; uGa, upper Gargasian.

Fig. 28 .

 28 Fig. 28. The upper Bedoulian sequence in the SC101 ANDRA well in the southeastern Paris Basin from FERRY (unpubl. ANDRA report), modified, and[START_REF] Courtinat | Les kystes de dinoflagellés des Argiles Ostréennes du Bassin de Paris, France[END_REF], modified. Upper right box, detail of the facies relationship between closely spaced wells (0,3 to 2,5 km apart) in the repository site. Note the crossing of the primary stratification by the two weathering fronts of the probable lateritic profile: OF, front of Fe concentration; AF, front of argilisation (primary rock, probably a marine clayey sandstone, fully altered into clay. T, transgressive trend; R, regressive trend; TS, transgression surface.

Fig. 29 .

 29 Fig. 29. Schematical stratigraphic correlation between the London-Paris Basin and the subalpine margin, especially regarding the upper Bedoulian sequence. AC, Atherfield Clay; AP, Argiles à Plicatules, Ba, Barremian; Ha, Hauterivian; HB, Hythe Beds; LG, Lower Greensand; lAb, lower Albian; lBd, lower Bedoulian; lGa, lower Gargasian; uBd, upper Bedoulian; uGa, upper Gargasian; W, Wealden deposits; G1, mid-Gargasian sandy turbidites of RUBINO (in FERRY & RUBINO, 1989) (Fig. 25).

Fig. 30 .

 30 Fig. 30. Exact timing of relative sea-level changes as a result of a probable overall transpressional tectonic movement in the southern subalpine basin during the Cenomanien-Turonian boundary δ 13 C shift. Events situated against the basinal Ondres section (after GROSHENY et al., 2017, modified, and work in progress). FR, forced regression due to uplift in the Rhodanian saddle; FP, forced progradation of the carbonate platform east of the strike-slip Rouaine fault and in the south Provence basin; LBS, UBS, lower, upper black shale of Vocontian sections; MPB, equiv. of the mid-Plenus bed of the Eastbourne reference section in southern England (see correlation in GROSHENY et al., 2017), T, beginning of the relative sea-level rise in each area, based on platform to basin stratigraphic transects constrained by isotope data (work in progress).

Acknowledgements

Thanks are due to Phil SALVADOR who kindly improved the English text.

This contribution is part of guide--book for a field--trip (May