# New insights on the age of the post-Urgonian manly cover of the Apt region (Vaucluse, SE France) and its implications on the demise of the North Provence carbonate platform

Camille Frau, Antoine Pictet, Jorge E. Spangenberg, Jean-Pierre Masse, Anthony J. -B. Tendil, Cyprien Lanteaume

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## To cite this version:

Camille Frau, Antoine Pictet, Jorge E. Spangenberg, Jean-Pierre Masse, Anthony J. -B. Tendil, et al. "New insights on the age of the post-Urgonian manly cover of the Apt region (Vaucluse, SE France) and its implications on the demise of the North Provence carbonate platform." Sedimentary Geology, 2017, 359, pp.44-61. 10.1016/j.sedgeo.2017.08.003. hal-01765621

HAL Id: hal-01765621

https://hal.science/hal-01765621v1

Submitted on 30 Jun 2025

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1 **New insights on the age of the post-Urgonian marly cover of the Apt region (Vaucluse, SE France) and its implications on the demise of the North Provence carbonate platform**

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4 Camille Frauª*, Antoine Pictetᵇ*, Jorge E. Spangenbergᶜ, Jean-Pierre Masseᵈ, Anthony J.-B.

5 Tendilᵈ and Cyprien Lanteaumeᵈ

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7 ª Groupement d'Intérêt Paléontologique, Science et Exposition, 60 bd Georges Richard, 83000

8 Toulon, France

9 ᵇ Department of Earth Sciences, University of Geneva, 13 Rue des Maraîchers, 1205 Geneva, Switzerland

10 c Institute of Earth Surface Dynamics, University of Lausanne, Bâtiment Géopolis, UNIL-Mouline, CH-1015 Lausanne, 1015 Lausanne, Switzerland

13 d Aix-Marseille Université, CNRS, IRD, CEREGE UM 34, 3 place Victor Hugo, 13331 Marseille, France

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16 *Corresponding author. E-mail addresses: camille_frau@hotmail.fr (Camille Frau) and Antoine.Pictet@unige.ch (Antoine Pictet)

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19 **Abstract**

20 Our contribution presents an integrated litho-, bio- and chemostratigraphic study of the best-preserved outcrops of the post-Urgonian marly cover (A¹ unit) of the North Provence carbonate platform. The study of the rich ammonite fauna from the Apt-Gargas area (SE Vaucluse) confirms that the A¹ unit is older than previously assumed and dated to the upper (but non-uppermost) part of the lower Aptian *Deshayesites forbesi* Zone of the Mediterranean standard zonation. This interval is assigned to the lower part of the *Roloboceras hambrovi*
Subzone as defined in the present contribution which is time equivalent to the spreading of the OAE 1a. Microfossil occurrences previously documented in the A¹ unit are consistent with our ammonite-age calibration. Unfortunately, the curves of the carbon and oxygen stable isotopes exhibit a correlative signal probably caused by an early diagenetic overprint which questions the previous use of the C-isotope signal for precise chronostratigraphic correlation with respect to the OAE 1a excursion. The top of the A¹ unit is marked by a burrowed firmground locally infilled and capped by glauconite-rich sandy marls which grade into the blue-grey muddy marls of the overlying A² unit. The hiatus associated to this discontinuity is equivalent to the culmination of the OAE 1a, including the uppermost *D. forbesi* Zone (= upper *R. hambrovi* Subzone as herein defined) and the lower *D. deshayesi* Zone. The revised calibration of the post-Urgonian marl imply that the ammonite-age calibration of the North Provence carbonate platform should be revised and questions the timing and driving mechanisms of its stepwise demise.

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40 **Keywords**

Urgonian; Ammonite; Biostratigraphy; OAE 1a; North Provence platform; France.

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43 **1. Introduction**

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In the southern part of the Monts de Vaucluse (Vaucluse, southeast France), the Urgonian-type trilogy of the North Provence carbonate platform – U¹ (bioclastic), U² (rudistid) and U³ (bioclastic) units *sensu* Leenhardt (1883) – is overlaid by the ~ 80 m-thick marlstones of the Apt–Gargas type area. The post-Urgonian marly succession was itself divided into three units based on their lithologies and macrofossil assemblages by Leenhardt (1883, p. 92); these are the A¹ unit – marly limestones with *Deshayesites* (*pro Ammonites in*

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51 Leenhardt, 1883) *consobrinus*, A² unit – clayed marls with *Dufrenoyia* (pro Ammonites in
52 Leenhardt, 1883) *dufrenoyi* and A³ unit – sandy marls with *Neohibolites* (pro Belemnites)
53 *semicanaliculatus*. An early Aptian (Bedoulian) age was formerly assigned to the A¹ unit
54 since it is overlaid by the Gargasian-type A² and A³ units defining the upper Aptian in the
55 sense of Kilian (1887). Recent studies on the Aptian-type succession (e.g. Ropolo & Gonnet,
56 2003; Dutour, 2005; Moullade et al., 2006, 2008) only focused on the stratigraphy and
57 paleontological content of the A² unit which includes the transition between the upper lower
58 (upper *Deshayesites deshayesi* Zone and *Dufrenoyia furcata* Zone) and the lower upper
59 Aptian (*Epicheloniceras martini* Zone) by means of ammonites. Unfortunately, the calibration
60 of the post-Urgonian A¹ unit with respect to the Mediterranean standard ammonite zonation
61 was much debated in the last decades (e.g. Masse et al., 1999; Moullade et al., 2009, 2012;
62 Masse & Fenerci-Masse, 2011, 2013a-b) and the lack of comprehensive work on its ammonite
63 assemblage has introduced contrasting hypothesis on the timing of the North Provence
64 platform demise.

65 Masse et al. (1999) and Masse & Fenerci-Masse (2011, 2013a-b) suggested that the
66 demise of the U³ platform calcarenites was related to the culmination of the Ocean Anoxic
67 Event (OAE) 1a dated to the *Roloboceras hambrovi* Subzone, placed in the middle part of the
68 *D. deshayesi* Zone as defined by Ropolo et al. (2000, 2006, 2008a-b) in the nearby Bedoulian-
69 type series (Cassis-Roquefort-la-Bédoule, Bouches-du-Rhône). This age would be supported
70 by (i) the occurrence of upper lower Aptian ammonites [including *Deshayesites deshayesi*
71 (d'Orbigny), *D. involutus* Spath, *Cheloniceras seminodosum* Sinzow, *C. cornuelianum*
72 (d'Orbigny), *Aconeceras* cf. *haugii* (Sarasin) and *Ammonitoceras* sp.] in the A¹ unit, indicative
73 of the *D. grandis* Subzone, (= upper *D. deshayesi* Zone sensu Ropolo et al., 2000, 2006,
74 2008a-b); and (ii) the record of the major positive OAE 1a carbon excursion at the top of the
75 U³ unit.
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Moullade et al. (2012, 2015) recently challenged these arguments based on a coupled analysis of microfossil and isotopic data obtained from an isolated outcrop of the A¹ unit at Croagnes, ~ 5km NE from Gargas. Indeed, the washed residues of the Croagnes section record the triple datum of the benthic foraminifera *Lenticulina* cf. *nodosa* (Reuss), the planktonic foraminifera *Schackoina* (*Leupoldina* *cabri* Sigal, and the ostracod *Protocythere bedoulensis* Moullade, which falls in the *R. hambrovi* Subzone in the nearby Bedoulian-type series. Moreover, the carbon isotopic signal of the Croagnes section would document the negative shifting of the OAE 1a global carbon cycle (C3 carbon segment *sensu* Menegatti et al., 1998), which is also dated of the *R. hambrovi* Subzone in the sense of Ropolo et al. (2000, 2006, 2008a-b). Moullade et al. (2012) therefore argued that the A¹ unit is older than it was previously assumed in the literature; a view being supported by the record of ammonites indicative of the *D. grandis* Subzone in the lower part of the overlying A² unit (Dutour, 2005). As a consequence, the timing and driving mechanism of the stepwise demise of the U² rudistid limestones and U³ platform calcarenites of the Urgonian trilogy is to be reconsidered.

For the time being, no continuous succession across the U³/A¹ transition was properly logged, and no comprehensive work on the ammonite fauna from the A¹ unit has been yet undertaken. Besides, Moreno-Bedmar et al. (2009) and Frau et al. (2015) pointed out that the *Deshayesites* taxa characterizing the *D. deshayesi* Zone of the Bedoulian-type series were misidentified by Ropolo and his co-workers who developed a distinct understanding of this zone by comparison with the Mediterranean standard zonation. Given these considerations, the present work aims to reappraise this issue by a combined litho-, bio- and chemostratigraphic study of the best preserved outcrops of the A¹ unit of the Apt-Gargas area. A systematic revision of its ammonite content is provided in appendix.

## 2. Geological setting
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## 2.1. *Palaeogeography*

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104 In southern France, the Lower Cretaceous Vocontian Basin constituted a marine
digitation open eastward to the Tethys at a palaeolatitude of 27–28° North (Masse et al., 2000;
105 Masse & Fenerci-Masse, 2013a-b). It was surrounded by shallow-water carbonate platforms
106 in its northern (Jura, Bas-Dauphiné), western (Bas-Vivarais) and southern (Provence) margins
107 (Arnaud-Vanneau et al., 1979; Masse, 1993; Masse & Fenerci-Masse, 2013). The Provence
108 platform records its maximum northward progradation during the upper Barremian with the
109 spreading of the rudistid biota from the Basse Provence to the Monts de Vaucluse where it
110 gives way to bioclastic-cherty formation toward the Vocontian Basin (Masse, 1976; Masse &
111 Fenerci-Masse, 2011). The progradation is punctuated by its collapse on the Martigues-
112 Toulon region which led to the deepening of the intra-shelf South Provençal Basin (Masse &
113 Fenerci-Masse, 2011, 2013; Frau et al., 2016), while a massive outbreak of *Palorbitolina*-
114 *Heteraster* communities occurs in North Provence (Masse, 1976; Masse & Fenerci-Masse,
115 2011; Léonide et al., 2012), then overlaid by a new rudistid unit (caprinid-bearing limestones
116 or U² unit *stricto sensu*) extending through the North Provence and Bas-Vivarais (Masse &
117 Fenerci-Masse, 2011). The bipolar progradation of the caprinid-bearing limestones is
118 suddenly interrupted, and ended by a micro-karstic subaerial exposure in North Provence
119 (Masse, 1976; Léonide et al., 2012, 2014) or a distinct aerial emersion in the Bas-Vivarais
120 (Pictet al., 2015). Outside south-western Bas-Vivarais, the exposure event is overlaid by a
121 thick succession of calcarenite-cherty facies (U³ unit), with a thick orbitolinid-coral episode
122 at its base in south-western Monts de Vaucluse (Léonide et al., 2012). The top of the U³ unit
123 is marked by a distinct hardground surface with trace of iron and/or phosphatic crusts, and can
124 be either overlaid by a complete (A¹ to A³ units) or partial (A² and/or A³ units) Aptian-type
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succession along the southern and eastern parts of the Monts de Vaucluse (Masse, 1976; Joseph et al., 1987; Masse & Fenerci-Masse, 2011).

The stepwise demise of the North Provence platform has been referred as drowning discontinuities by Masse & Fenerci-Masse (2011), and labelled D1 to D4 (see Fig. 1). In the study area, the demise of the U³ platform calcarenites, replaced by A¹ yellowish marls, corresponds to the D3 discontinuity, while the change from the A¹ yellowish marls to the A² blue-grey marls refers to the D4 discontinuity.

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## 2.2. *Studied area*

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The Urgonian-type series of North Provence and its overlying marly cover crop out well between the villages of Gordes and Rustrel, located along the southern flank of the Monts de Vaucluse, that gently dips toward the plain of Apt (Vaucluse, Fig. 2). Four main areas located within the Parc Naturel Régional du Lubéron (PNRL) were investigated (Fig. 2):

- In the Murs-Joucas area, ~ 14km NW of Apt, the transition between the U³ and A¹ units crops out in the extended gullies (i.e. Les Rabots - abbreviated as Rab., Sumian - Sum., La Jaumière - Jau.; Fig. 2) between the departmental roads D4 and D102A. The uppermost part of the U³ unit is composed of coarse-graded biocalcarenites cropping out as a large structural surface (D3 discontinuity sensu Masse & Fenerci-Masse, 2011) crisscrossed by a set of syn-sedimentary 5-10 NS and 20-30 EW faults delimiting irregular parallelograms on the field. The U³ unit terminates with a distinct hardground surface capped by a thin bed of glauconitic sandy marls, irregular in thickness. It is overlaid by the A¹ unit composed of ~10 m-thick alternation of three bundles of limestone beds and interbedded marls (Fig. 3A). Facies of the limestone bundles corresponds to a quartz-rich spongolithic packstone (Fig. 3B). The two first bundles yielded the age-diagnostic ammonite fauna studied in this work, in
association with the echinoid *Miotoxaster collegnoi* Sismonda and undetermined endobiontic bivalves. The third limestone bundle ending the A¹ unit is topped by a distinct firmground (D4 discontinuity *sensu* Masse & Fenerci-Masse, 2011) with *Thalassinoides* furrows infilled with glauconite-rich sands (Fig. 3C, D). The lowermost part of the overlying A² unit is not visible in the Murs-Joucas area, but a recent urbanization work at Les Rabots allowed us to collect small-sized pyritic ammonites in monotonous blue-grey marls in its lower part.

- A poorly-exposed succession of the A¹ and A² units crops out 400m NE of the village of Croagnes within the forest of Coste Granière (Cro - Fig. 2). The outcrop previously studied by Moullade et al. (2012) corresponds to 13 m-thick yellowish to bluish marls, rich in *M. collegnoi* (Fig. 4A). Another outcrop, located 550 m E of the village, allows to observe the D4 discontinuity between the A¹ and A² units. It is characterized by the burrowed firmground at the top of a limestone bundle of the topmost A¹ unit, overlaid by 20 cm-thick glauconite-rich horizon of sandy marls including numerous small-sized belemnites (Fig. 4B). This level is laterally discontinuous and overlaid by the monotonous blue-grey marls of the A² unit.

- At the foot of the so-called Low-Noise Underground Laboratory (Rustrel - Rus.; Fig. 2), the U³ unit abruptly dips to the south and exhibits a distinct lithostratigraphic succession since its upper part is characterized by an episode of cherty limestones bounded by two hardground surfaces (Masse & Fenerci-Masse, 2011). It is overlaid by a reduced A¹ unit (Fig. 5A), composed of 1 m-thick *Toxaster*-bearing yellowish marls (Fig. 5B). Rare specimens of non-diagnostic ammonites (*Pseudohaploceras* sp.) have been collected in a lateral equivalent section (Les Vignals - Vig.; Fig. 2). The A¹ unit is topped by the glauconitic burrowed firmground and overlaid by the blue-grey marls of the A² unit (Fig. 5C). It should be noted that the cherty limestones episode topping the U³ unit was previously considered as a lateral equivalent of the A¹ unit by Masse & Fenerci-Masse (2011, fig. 11, 20) who, *de facto*, fixed the D3 discontinuity at the base of this episode. However, the authors overlooked the presence
176 of a reduced A¹ succession above the cherty limestones and nothing concrete corroborates the
177 coevality between the cherty limestones episode and the lower part of the best-developed A¹
178 succession of the Murs-Joucas area described above. Ongoing study on this issue as part of
179 the doctoral thesis of one of us (A.J.-B.T.) supports that the cherty limestones episode of the
180 Rustrel section represents a syn-depositional lateral variation of the topmost U³ platform
181 calcarenites. This view is herein followed in this work and will be addressed elsewhere.

182 - The Clavaillan section located along the local road D2, ~ 2 km WSW of Croagnes
183 (Cla; Fig. 2), was previously investigated by Dutour (2005) and Moullade et al. (2012). It
184 corresponds to a ~ 25 m-thick succession of blue-grey marls of the A² unit, that gently dips to
185 the south (Fig. 6). The contact with the underlying A¹ unit is not visible but small-sized
186 pyritic ammonites of the *D. grandis* Subzone (i.e. upper *Deshayesites deshayesi* Zone) have
187 been collected in the first five meters of the section (Dutour, 2005 plus our own record).
188 Ongoing sampling at Clavaillan suggests that the first occurrence of *Dufrenoyia* is recorded in
189 the limestone marker bed that falls in the middle part of the section (Fig. 6).

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191 **3. Methods**

192

193 The sections of Les Rabots-Sumian-La Jaumière and Rustrel were measured and
194 sampled for geochemistry and macrofossils during the summers 2012 and 2013 by one of us
195 (A.P.). Additional fieldwork in other sections has been subsequently undertaken in 2015-
196 2016 by the authors. For the chemostratigraphic study, a total of 36 samples from Les Rabots
197 were analysed; 4 from the top of the U³ unit and 32 through the A¹ unit. A total of 10 samples
198 were collected at Rustrel; 1 from the top of the U³ unit and 7 through the A¹ unit and 2 at the
199 base of the A² unit. Samples were sawn to avoid veins and altered parts, and milled with an
200 agate crusher. Stable carbon and oxygen isotope analyses were performed at the University of
Lausanne following the same methodology described in Pictet et al. (2015). Values are reported in ‰ PDB (Vienna Pee Dee Belemnite). Total phosphorus (P) content was measured at the same institute on powdered bulk-rock samples treated according to the ascorbic acid method of Eaton et al. (1995).

About fifty ammonite specimens were collected from the Murs–Joucas and the Rustrel areas by the authors of the present contribution. The systematic description of the studied taxa is provided in appendix. The ammonite zonation used in this work follows the standard scheme ratified by the IUGS Lower Cretaceous Ammonite Working Group (Reboulet et al., 2014). It exists major discrepancies with the Ropolo's zonation based on the Bedoulian-type succession that was so far applied for the North Provence platform series (e.g. Masse & Fenerci-Masse, 2011, 2013a-b; Léonide et al., 2012; Moullade et al., 2009, 2012). The major discrepancies (i.e. vertical extension of the *D. deshayesi* Zone, stratigraphic position of the *R. hambrovi* Subzone) with the Ropolo's zonation have been discussed and revised by Frau et al. (2015) for which the reader is referred. To avoid redundancy, a comparative ammonite chart is given in Fig. 7.

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## 4. Bio- and chemostratigraphy of the A¹ Unit

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### 4.1. *Ammonite occurrences*

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During the course of this study, two ammonites were collected at the top of the bioclastic U³ unit from the Murs–Joucas area. One of the two fragmented specimens is tentatively identified as *Deshayesites* cf. *kiliani* (Spath) (Fig. 8a-b). Above, a rich ammonite fauna has been collected within the two first limestone bundles of the A¹ unit in the Murs–Joucas area, as well as in the reduced succession of the Rustrel area. The material at our
226 disposal is preserved as fragmented calcareous molds whose generic and/or specific
227 assignments are in most of cases left in open nomenclature. Nevertheless, the fauna is
228 diversified and represented by five families including the Deshayesitidae *Deshayesites* cf.
229 *forbesi* Casey (Fig. 8c-d), *Deshayesites* cf. *euglyphus* Casey (Fig. 8e-h, m-n) and *Deshayesites*
230 sp. (Fig. 8k-6, i-j), the Douvilleiceratidae *Procheloniceras* sp. (Fig. 9a-l), the Ancyloceratidae
231 *Ammonitoceras* sp. (Fig. 9m-r) and Ancyloceratidae gen. et sp. indet. (Fig. 10a-b), the
232 *Acrioceratidae Toxoceratoides* aff. *royeri* (d'Orbigny) (Fig. 10c-d) and the Desmoceratidae
233 *Pseudohaploceras* sp. (Fig. 10e-p). The deshayesitids (33.3%) dominate the assemblage,
234 followed by the cheloniceratids (25.9 %) and the desmoceratids (18.5 %) forms. The
235 abundance of deshayesitids and cheloniceratids, interpreted as shallow to deep nekto-benthik
236 forms (Reboulet et al., 2005), and the lack of mesopelagic phylloceratid and lytoceratid
237 migrants, suggest that the ammonite fauna of the A¹ unit inhabited a distal neritic setting.

238 For the time being, no ammonite has been yet collected in the discontinuity between
239 the A¹ and A² units. Nevertheless, the lowest occurrence of ammonites in the A² unit at the
240 Clavaillan section marks the upper *D. deshayesi* Zone and lower *D. furcata* Zone (Dutour,
241 2005) (see also 10q-u). The ammonite assemblage collected *ex-situ* from the lower part of the
242 A² unit at Les Rabots is younger and composed of *Dufrenoyia dufrenoyi* (d'Orbigny)
243 (Deshayesitidae) (Fig. 10v-w), *Ammonitoceras* sp. (Ancyloceratidae) (Fig. 10x-y) and
244 *Aconeceras nisum* (d'Orbigny) (Desmoceratidae) (Fig. 10z); an association that marks the
245 upper part of the *D. furcata* Zone (Dutour, 2005). The abundance of the small-sized pyritic
246 ammonite faunas in this time interval forms an easily recognisable horizon in the A² marls of
247 the Apt-Gargas area (Dutour, 2005 with references therein).

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249 4.3. Geochemistry

250 4.3.1. *Stable isotopes*
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The measured δ¹³C values at Les Rabots-Sumian-La Jaumière vary between -1 and 2 ‰ (Fig. 11). The topmost part of the U³ unit exhibits negative values around -1 and -0.5 ‰, while the A¹ unit shows a strong enrichment of 2 to 2.5 ‰. The lower third of A¹ unit records a positive excursion from 1.5 to 2‰, followed by a negative trend above the first bundle of limestone beds (decreasing from -2 to -0.5 ‰). The δ¹⁸O curve exhibits a similar pattern with more negative values in the topmost part of U³ unit with values reaching -6 to -5.5 ‰ (Fig. 11), followed by a positive, then negative shift through the A¹ unit ranging from ~ -4.5 to -2.5‰.

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The δ¹⁸O/δ¹³C cross-plot shows a strong variance with a R square of 0.8 (Fig. 11).

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The measured δ¹³C values at Rustrel vary between 1.5 and 3.2 ‰ (Fig. 12). The topmost part of the U³ unit exhibits a positive value equals to ~ 3 ‰. The A¹ unit shows a strong decrease of 1 ‰ at its base followed by a positive excursion from 2 to 3 ‰ and a limited negative trend. The base of the A² unit records a strong decrease in the basal glauconitic layer followed by a marked positive shifting reaching value equals to 3.2 ‰ in the blue-grey marls. The δ¹⁸O curve exhibits a similar pattern (Fig. 12). The δ¹⁸O/δ¹³C cross-plot shows a strong variance with a R square of 0.62 (Fig. 12).

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### 4.3.2. *Phosphorus content*

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At Les Rabots-Sumian-La Jaumière, the total phosphorus content from the topmost U³ unit displays a general background level between 100 and 110 ppm with a strong enrichment up to 275 ppm in the MUR1 sample (Fig. 11). No major peak is recorded in the A¹ unit but only a progressive enrichment is documented in the lower third from 125 to 180 ppm, and then an upward decrease of the values from 180 to 125 ppm. An unusual variance
276 between the total phosphorus content and the stable isotopes is observed with a strong
277 correlation with R square of 0.66 with the δ¹³C, and of 0.76 with the δ¹⁸O, excepted for
278 sample MUR31 that was excluded from the quantification of the variance (Fig. 11),
279 considered as an anomaly.

280 At Rustrel, the total phosphorus content from the topmost U³ unit and from the lower
281 third of the A¹ unit displays a general background level between 200 and 350 ppm with a
282 limited enrichment up to 390 ppm on the hardground surface (Fig. 12). A major peak is
283 recorded at the transition between the A¹ and A² units with values reaching 840 ppm. The
284 total phosphorus content is herein inversely correlated to the stable isotopes (Fig. 12).

285

286 **5. Discussion**

287

288 5.1. Ammonite-age calibration of the post-Urgonian marly cover

289

290 5.1.1. *The A¹ unit*

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292 Our study documents the abundance of *Deshayesites* of the *forbesi* group in the post-
293 Urgonian A¹ unit of North Provence. Following its introduction in the Lower Greensand
294 (Casey, 1964; Casey et al., 1998), *D. forbesi* is used as a zonal index of the upper part of the
295 lower Aptian in the Mediterranean standard ammonite zonation (Fig. 7). However, the index
296 species only ranges through the middle part of the zone it typifies in the Lower Greensand
297 (i.e. *D. kiliani* and *D. callidiscus* subzones sensu Casey et al., 1998), since its record below
298 (*D. fittoni* Subzone) and above (*D. annelidus* Subzone) its acme is controversial as based on
299 unfigured or poorly-preserved specimens of doubtful specific assignment (Bersac & Bert,
300 2012). As a result, the boundaries between the original understanding of the *D. forbesi* Zone
301 and its standard definition remains unclear.

302 In the Mediterranean Tethys, the upper part of the *D. forbesi* Zone is characterized by
303 the *Roloboceras hambrovi* Subzone which includes the global negative and positive shifting
304 of the OAE 1a carbon excursion (e.g. Moreno-Bedmar et al., 2009, 2012; Frau et al., 2015).
305 However, the index species *R. hambrovi* never reaches the upper part of the *D. forbesi* Zone
306 in the Lower Greensand since its acme is similar to those of *D. forbesi* dated to the *D. kiliani-*
307 *D. callidiscus* subzones time interval (Casey et al., 1998) (see also Fig. 13). Indeed, *R.*
308 *hambrovi* gives way to *Megatyloceras* of the *coronatum* (Rouchadzé) – *ricordeanum*
309 (d'Orbigny) group at the base of the *D. annelidus* Subzone (Casey, 1961) which correlates to
310 the positive shifting of the OAE 1a carbon excursion (Gröcke et al., 1999). As noticed by
311 Bersac & Bert (2012), the current understanding of the *R. hambrovi* Subzone in the
312 Mediterranean Tethys mostly relies on the acme of *Megatyloceras* members which is coeval
313 with the latest occurrence of *R. hambrovi* (Fig. 13). As the result, the *R. hambrovi* Subzone of
314 the Mediterranean standard zonation only correlates with the uppermost part of the British *D.*
315 *forbesi* Zone (i.e. *D. annelidus* Subzone sensu Casey et al., 1998) and, in that sense, its lower
316 boundary postdates the first occurrence and most of the acme of its index species. In the
317 interest of efficiency, the base of the *R. hambrovi* should be lowered at the FO of *R.*
318 *hambrovi*. Doing this, the *R. hambrovi* subzone now includes the succeeding acmes of the
319 genera *Roloboceras* and *Megatyloceras* (see Fig. 13), which includes the spreading (topmost
320 C2 to C3 carbon segments) and culmination (C4 to C6 carbon segments) of the OAE 1a,
321 respectively.

322 By the record of the *D. forbesi* acme, the A¹ unit correlates with the lower part of the
323 *R. hambrovi* Subzone as herein defined. Unfortunately, none of the studied ammonites from
324 the A¹ unit could be yet referred to *Roloboceras*, but its absence can be explained by local
ecological constraints. Indeed, members of the genus *Roloboceras* are restricted to proximal
neritic platforms of the Mediterranean Tethys (Moreno-Bedmar et al., 2009; Pictet et al.,
2015; Reboulet et al., 2011). Nevertheless, this age is also supported by the record of the
nautiloid *Heminautilus saxbii* (Morris) in the A¹ unit of La Jaumière, which is considered as
an additional biomarker of the *R. hambrovi* Subzone of the Mediterranean Tethys (Baudouin
et al., 2016, pl. 20, fig. 1a-b). Following Moullade et al. (2012), our ammonite-age calibration
contradicts with the current dating of the A¹ unit proposed by Masse & Fenerci-Masse (2011)
who referred it to the upper part of the *D. deshayesi* Zone.

333

334 5.1.2. *The base of the A*<sup>2</sup>*unit*

335

The lack of ammonite prevents a direct calibration of the discontinuity at the transition
between the A¹ and A² units, previously referred as the D4 discontinuity by Masse & Fenerci-
Masse (2011). Nevertheless, the occurrences of ammonites of the upper (but non-uppermost)
part of the *D. forbesi* Zone in the A¹ unit, and the occurrence of ammonites of the upper *D.
deshayesi* Zone in the lower part of the A² unit (Dutour, 2005) suggest that the hiatus
materialised by the D4 discontinuity encompasses the uppermost *D. forbesi* Zone (upper *R.
hambrovi* Subzone as herein defined) and the lower *D. deshayesi* Zone. The depositional
hiatus is undoubtedly coeval with the culmination of the OAE 1a-related oceanic anoxia by
comparison with the Tethyan basinal successions constrained by bio- and chemostratigraphy
(e.g. Moreno-Bedmar et al., 2009, 2012; Najarro et al., 2011; Pictet et al., 2015; Frau et al.,
2015). However, the latter discontinuity contrasts with the continuous sedimentation observed
in deposits of same age overlying the nearby Bas-Vivarais platform (Pictet et al., 2015), the
Vocontian (Huck et al., 2011 with references therein) and South Provence (Stein et al., 2012;
Frau et al., 2015) basins. Of particular interest is the report in North Provence of active

337

338

339

340

341

342

343

344

345

346

347

348

349
tectonics below and above the latter hiatus and whose peak activities are associated with
major discontinuities (Joseph et al., 1987). This offers a likely explanation for the A¹–A²
discontinuity, while the deposition of the overlying A² and A³ units relates to a period of
regional tectonic relaxation as assumed by Kandel (1992). These observations tend to support
a tectonically-controlled sedimentation of the post-Urgonian marly cover but the description
of tits timing is out of the scope of this work and will be addressed elsewhere.

356

## 5.2. Significance of the stable isotope records

358

Prior to this study, the carbon isotope record of the A¹ unit has only been documented at Croagnes by Moullade et al. (2012). The isotopic variations of the 8 samples from the isolated section of Croagnes "appear to be consistent with the middle/upper part of the C3 isotopic stage and its transition towards C4" (Moullade et al., 2012, p. 196). By comparison with the Bedoulian-type series, this chemostratigraphic-derived age is coherent with the upper D. forbesi Zone as defined by Frau et al. (2015). This would also be supported by the carbon values obtained at the base of the Clavaillan section which exposes the lower part of the A² unit. According to Moullade et al. (2012, p. 196), the measured samples "are significantly higher than those from Croagnes and very close to those of the C6/C7 transition" which correlates with the D. deshayesi Zone as interpreted by Frau et al. (2015) in the Bedoulian-type series. The A¹ unit and the lower part of the A² unit would include the negative, then positive shifting of the OAE 1a carbon excursion.

Our carbon values documented at the Les Rabots and Rustrel sections are also
consistent with the C3 carbon segment, however, the δ¹⁸O/δ¹³C cross-plots exhibit high
variance and a strong correlation coefficient (R square equals to 0.8 inside the A¹ unit). At
Les Rabots, the phosphorus content also shows a strong variance with the stable isotope

372

373

374
signals. The phased signals of the stable isotopes, along with the phosphorus trend, can be interpreted as an early diagenetic overprinting (e.g. Joachimski, 1994; Immenhauser et al., 2008; Korbar et al., 2012). As pointed out by Masse & Philip (1976), a regional tectonic event (i.e. the Durancian Uplift) led the North Provence platform to be exposed during the Albian *pro parte* to Early Cenomanian times (~3Ma duration). Intense subaerial erosion occurred South to the Monts de Vaucluse (e.g. Orgon - Masse & Fenerci-Masse, 2013; Martigues - Masse, 1976, Léonide et al., 2014) while contemporaneous laterites (i.e. Roussillon, Rustrel) developed in the vicinity of the study area under a warm and humid climate (Triat, 1983, 1985). The post-Urgonian marls were probably close to the alteration front as Albian deposits did not exceed a few tens of meters (Joseph et al., 1987, 1989). Extensive isotopic resetting probably originated from meteoric fluid circulations or meteoric water lenses related to this Mid-Cretaceous uplift. In this regard, present-day microporosity observed in the underlying Urgonian-type series is related to Durancian meteoric fluids (Léonide et al., 2014).

As a consequence, the plausible diagenetic overprint of the carbon signal prevents its use for a precise chronostratigraphic correlation with respect to the OAE 1a excursion. These results raise questions about the interpretation of the carbon isotope stratigraphy from the Croagnes and Clavaillan sections proposed by Moullade et al. (2012). Unfortunately, the authors did not published their δ¹⁸O dataset for further discussion.

393

### 5.3. Implications for the demise of the North Provence platform

395

The evolution of the Urgonian-type shallow-water carbonate platform of North Provence is thoroughly close to those outcropping in the nearby Bas-Vivarais region since their rudist-rich biofacies (i) overly a mixed heterozoan-photozoan platform carbonate formation of early late Barremian age (i.e. Lower Urgonian Member *sensu* Lafarge, 1978);

396

397

398

399
(ii) begin with *Agriopleura*-dominated limestones (Upper Urgonian Member *sensu* Lafarge, 1978) ended by local emersive surface (Masse & Fenerci-Masse, 2011), and terminate with caprinid-dominated limestones; and (iii) record a major change in trophic conditions evidenced by orbitolinid mass accumulation (*Palorbitolina*–*Heteraster* guide level in Lafarge, 1978). The massive outbreak of *Palorbitolina*–*Heteraster* communities in North Provence and Bas-Vivarais is dated to the *I. giraudi*–*M. sarasini* (pars) zones interval (Masse & Fenerci-Masse, 2011; Frau et al., submitted) and coincides with the drowning sequence of the Urgonian series of southern France which initiated the deepening of the South Provençal Basin (Masse & Fenerci-Masse, 2011; Frau et al., 2016).

To the difference of the North of Provence where only a minor subaerial exposure is documented (Masse & Fenerci-Masse, 2011; Léonide et al., 2012, 2014), the erosive surface topping the caprinid-bearing limestones of the Bas-Vivarais records three successive generations of infills in epikarstic cavities including (1) palustrine to continental micrite, (2) continental reddish microbreccia and (3) marine bioclastic limestone or glauconitic sandy marls with phosphatic crust; giving evidence of a long-termed aerial to subaerial exposure (Pictet et al., 2015). This discontinuity is then capped by open-marine marls and limestones of the Chabert Fm., subdivided into, from bottom to top, the Violette, Roche-Renard and Picourel members (Pictet et al., 2015; Pictet & Delanoy, 2017), dated by ammonites between the upper *D. forbesi* (lower *R. hambrovi* Subzone as herein defined) to the upper *D. furcata* zones (Pictet et al., 2015). Contrary to North Provence, the Violette Mb. records the concomitant acme of *D. gr. forbesi* and *R. gr. hambrovi* and the succession is continuous through the upper *R. hambrovi* Subzone (as herein defined) and the lower *D. deshayesi* Zone. Nevertheless, a minor hiatus locally occurs above (i.e. base of the Frayol Fm.) and includes the uppermost *D. deshayesi* Zone and part of the *D. furcata* Zone (Pictet et al., 2015). It should also be noted that ammonite evidences of the *D. forbesi* Zone and/or *D. deshayesi*
Zone are lacking in south-western localities of the Bas-Vivarais (i.e. in more proximal position), and only age-diagnostic taxa of the *D. furcata* Zone have been documented above the caprinid-bearing limestones (Pictet et al., 2015). Notwithstanding disparate syn-depositional hiati or erosion, the post-Urgonian levels of Bas-Vivarais are obviously time equivalent of the A¹–A² (*pro parte*) units of North Provence (Fig. 14). By their ammonite assemblages, these levels are coeval with the Marly Calcareous Member (*sensu* Moullade et al., 2000) of the Bedoulian-type series which encompasses the upper part of the *D. forbesi* to *D. furcata* zones interval as reinterpreted by Frau et al. (2015).

Considering that the deposition of the caprinid-bearing limestones of SE France are isochronous (Masse & Fenerci-Masse, 2011, 2013), the bioclastic-cherty U³ formation of North Provence can be regarded as a time equivalent deposit to the erosive exposure topping the Urgonian series of the Bas-Vivarais (Fig. 14). This is evidenced in north-eastern Bas-Vivarais where an equivalent, but reduced, U³ unit locally crops out between the caprinid-bearing limestones and the Chabert Fm. (Masse & Fenerci-Masse, 2011, fig. 13). It was referred as part of the Lafarge Formation by Pictet et al. (2015) and erroneously considered as a lateral equivalent of the caprinid-bearing limestones of the Bas-Vivarais. However, it leaves no doubt that the U³ formation is beveled into the top Urgonian discontinuity between Serviers-et-Labaume and Bourg-Saint-Andéol and overlaid by the Chabert Fm. (Fig. 14).

Although no revision of its rare ammonite occurrences has been yet undertaken, the U³ formation was assigned to the lower *D. deshayesi* Zone *sensu* Ropolo et al. (2000, 2006) by Masse & Fenerci-Masse (2011, 2013) and Léonide et al. (2012). This biostratigraphic dating has so far implied the causal relationships between the regional demise of the Urgonian rudistid biota and the spreading of the OAE 1a-related oceanic anoxia dated to the upper *D. forbesi-D. deshayesi* zones interval (op. cit.). The change from limestone- to marl-dominated sedimentation in the Bedoulian-type series was considered by the authors as a coeval evidence
(Masse & Fenerci-Masse, 2011, 2013; Léonide et al., 2012), and linked to the pulsed rock-forming nannoconid declines predating the massive deposition of OAE 1a black shales in peri-platform settings of the Tethys (Huck et al., 2011). However, this major lithological change is now interpreted as part of the upper *D. forbesi* Zone in the Bedoulian-type series and it should be thus correlated with the demise of the U³ platform calcarenites and not with those of the caprinid-bearing limestones as assumed by the latter authors. Accordingly, the North Provence U³ unit can be considered as a full, or at least partial, time equivalent of the Calcareous Member of the Bedoulian-type series, which includes the *D. oglanlensis–D. forbesi* (pars) zones interval (Frau et al., 2015).

The new calibration of the post-Urgonian marly cover therefore implies that the collapse of the Urgonian rudistid biota (caprinid-bearing biofacies) of SE France is older than it is actually assumed, and obviously predates the spreading and culmination of the OAE 1a. In addition, the duration of the emersion of caprinid-bearing limestones is longer than it was previously assumed but its calibration is open to discussion. To this respect, the forthcoming study of new ammonite findings from the U³ unit in the Monts de Vaucluse will allow us to precise the location of the base of the Aptian within the North Provence platform series and propose a new scenario for the demise of the rudistid biota of the Urgonian-type region.

## 6. Conclusions

This contribution presents a coupled bio- and geochemical analyses of the post-Urgonian marly cover (A¹ and A² units) of the North Provence platform (SE France). The integrated (ammonite and microfossil) biostratigraphic dataset allowed us to precise the age assignment of the A¹ unit to the upper (but non-uppermost) part of the standard *D. forbesi* Zone. The A¹ unit terminates with a glauconitic discontinuity including the upper *R. hambrovi*
Subzone (as herein defined) and the lower *D. deshayesi* Zone. This interval is coeval with the culmination of the OAE 1a. The carbon stable isotope record of the $A^1$ unit is overprinted by an early and/or late meteoritic diagenetic phase which questions its use as a geochemical marker of the OAE 1a excursion in the North Provence platform. Nevertheless, the record of litho- and biological markers of the spreading of the OAE 1a at the transition between the $U^3$ and $A^1$ units proves that the demise of the rudistid biota of the North Provence platform obviously occurs earlier than it is actually assumed in the literature. However, its timing remains unclear due to the lack of precise calibration of the $U^3$ unit and prevent the understanding of the driving mechanisms involved.

484

## 485 Acknowledgments

486

We gratefully acknowledge Christine Balme and Stéphane Legal for their help in obtaining the land access permit DDT/SEMN.2012/141 from the Parc Naturel Régional du Lubéron. Warm thanks are due to Arnaud Clément (Montélimar) for the generous donation of his ammonites from the $A^1$ unit, Laurent Nicod (Université de Lausanne) who carefully prepared the thin sections, and Mukerrem Fenerci-Masse (Marseille) for her continuous support during the preparation of the manuscript. Valuable discussions with Gérard Delanoy and Michel Moullade (Nice-Sophia-Antipolis Université), Jean Borgomano, Philippe Léonide and François Fournier (Aix-Marseille Université) greatly improved the early draft of this paper. The research of one of us (A.P) was financially supported by the Swiss National Science Foundation (200021_144459) and the University of Lausanne. The constructive comments of the editor in-chief and reviewer Luc G. Bulot (Aix-Marseille Université, NARG, University of Manchester) are highly appreciated and improved the manuscript.
Special thanks are finally due to Jonathan Redfern (NARG, University of Manchester) who carefully proofread the manuscript prior to the final submittal.

501

## 502 Appendix. Systematic palaeontology

503

The studied ammonite specimens are deposited in the Pictet collection, housed in the Museum of the Parc Naturel Régional du Lubéron (PNRL), at Apt (Vaucluse, France).

506

Subclass Ammonoidea Zittel, 1884

Superfamily Desmoceratoidea Zittel, 1895

Family Desmoceratidae Zittel, 1895

Genus *Pseudohaploceras* Hyatt, 1900

Pseudohaploceras sp.

512

Material: Six specimens – PNRL.1834 (Fig. 10e-f), PNRL.1809 (Fig. 10g-h), PNRL.1810 (Fig. 10i-j), PNRL.1833 (Fig. 10k-l), PNRL.1811 (Fig. 10m-n), PNRL.1812 (Fig. 10o-p) from La Jaumière.

Description: Three middle-sized, slightly deformed body chambers (PNRL.1809, PNRL.1810, and PNRL.1834), and three small-sized, crushed phragmocones (PNRL.1811, PNRL.1812 and PNRL.1833). The section of the inner whorls is high-oval, higher than wide and compressed with rounded flanks as growth increases. In specimens PNRL.1809, PNRL.1810, and PNRL.1834, the adult section is sub-oval to sub-rounded. The umbilical margin is convex with a slight overhang. The ornamentation is marked by irregular alternation of strong, straight primary ribs and straight to flexuous intercalatories. Primaries start from the umbilical margin. They are preceded by large constrictions, sometimes followed by weaker ones.
Intercalatories begin from pinched umbilical clavi to which they can be bifurcated. Firstly prorsiradiate on the lower third, they bend slightly backward on the flank and radially cross the rounded venter.

Discussion: The material at our disposal does not allow a specific assignment because of its poor state of preservation. All specimens were collected close to the base of the A¹ unit.
Representatives of the genus *Pseudohaploceras* are long-ranging taxa spanning the Barremian and Aptian stages.

Superfamily Deshayesitoidea Stoyanow, 1949

Family Deshayesitidae Stoyanow, 1949

Genus *Deshayesites* Kazansky, 1914

*Deshayesites* cf. *forbesi* Casey, 1961

Material: The single specimen PNRL.1800 (Fig. 10c-d) from Joucas.

Description: Body chamber of a medium-sized deshayesitid form. The ornamentation is composed of alternation of slightly flexuous primary and secondary ribs, starting, more or less regularly, in the upper third of the flank. Secondary ribs can sometimes branch on the primaries which can be enlarged below the point of furcation. The whorl section is sub-oval, moderately broad, with rounded flanks and venter. The umbilical wall is oblique. The primary ribs are marked by a slight retrocurvature in the umbilical margin.

Discussion: The specimen at our disposal matches the adult morphology and ribbing of the type series of *D. forbesi* illustrated by Casey (1964). The acme of *D. forbesi* in its type locality (Lower Greensand - Casey, 1963; Casey et al., 1998) is coeval with those of closely allied typological taxa introduced by Spath (1930) and Casey (1964) which were considered
548 as its micro- (e.g. *D. punfieldensis* Spath, *D. gracilis* Casey) or macroconch (e.g. *D. topleyi* Spath, *D. kiliani* Spath, *D. euglyphus* Casey) morphotypes by Bersac & Bert (2012).

549
550
Deshayesites cf. *euglyphus* Casey, 1963

551
552
Deshayesites cf. *euglyphus* Casey, 1963

553
554
Material: Three specimens – PNRL.1803 (Fig. 8e-f) and PNRL.1804 (Fig. 8m-n) from Joucas section, and PNRL.1832 (Fig. 8g-h) from Murs.

555
556
557
558
559
560
561
562
Description: Fragments of medium-sized deshayesitid phragmocones and/or body chambers.
The ornamentation is composed of, more or less regular, strong bifurcate ribs with broad branches and rare secondaries. The latter rarely branch with the primaries such as in specimens PNRL.1803 and PNRL.1832. Ribs are enlarged in the umbilical margin and bifurcate at/or above mid flank. The whorl section is sub-oval to trapezoidal, moderately broad, higher than wide, with rounded to nearly flat flanks. The maximum thickness is situated near the umbilical margin. The ventral area is moderately large and rounded. The umbilical wall is oblique to steep with enlarged beginning of the primary ribs.

563
564
565
566
567
568
569
570
Discussion: The size, morphological features and adult ornamentation (i.e. strong, spaced, slightly flexuous, bifurcate ribs with thickened umbilical bullae) of the type specimens of *D. euglyphus* illustrated by Casey (1964) match well to those of our specimens. Bersac & Bert (2012) assumed that *D. euglyphus* represents a macroconch morphotype of *D. forbesi* with a moderately robust ornamentation and evolute coiling since both species share a similar stratigraphic range in the Lower Greensand.

570
Deshayesites cf. *kiliani* Spath, 1930

571
572
Material: The single specimen PNRL.1808 (Fig. 8a-b) from Murs (Sumian ravine).
573 Description: The specimen at our disposal corresponds to a medium-sized phragmocone. The
574 section is sub-trapezoidal to sub-rectangular, higher than wide, with nearly flat flanks and
575 large rounded venter. The maximum thickness of the whorl is close to the umbilical margin,
576 marked by a steep, convex to oblique wall. The ornamentation is composed of large and
577 pinched peri-umbilical bullae to which smooth primary ribs arise. The ribs are weakened at
578 mid flank but they bifurcate as pair of branches on the upper third.

579 Discussion: The specimen was collected at the top of the U³ unit. Its morphology and ribbing
580 match the topotype of *D. kiliani* illustrated by Casey (1963, pl. 49, fig. 1a-b) at similar growth
581 stage. According to Bersac & Bert (2012), *D. kiliani* represents another macroconch
582 morphotype of *D. forbesi*.

583

584 *Deshayesites* sp.

585

586 Material: Four specimens – PNRL.1805 (Fig. 8k-1) and PNRL.1802 from La Jaumière, and
587 PNRL.1801 and PNRL.1807 from Les Rabots.

588 Description: Several fragments of body chamber of medium to large-sized deshayesitid forms.
589 Specimens PNRL.1805, 1802, and 1801 show broad, spaced bifurcate ribs with rare
590 secondaries. The whorl section is sub-oval, broad, higher than wide. The umbilical wall is
591 oblique to steep with enlarged beginning of the primary ribs.

592 The specimen PNRL.1807 is middle-sized fragment of a body chamber. The section is sub-
593 trapezoidal to sub-rectangular, higher than wide, with slightly rounded flanks and large
594 rounded venter. The umbilical margin is steep, convex to oblique. The ornamentation is
595 composed of spaced, simple, and straight to slightly flexuous primary ribs.
596 Discussion: The fragmented specimens at our disposal do not allow specific assignment by
597 their poor state of preservation. Nevertheless, their morphological and ornamental features are
598 closely allied to the macroconch taxa synonymized with *D. forbesi* by Bersac & Bert (2012).
599

600 *Deshayesites grandis* Spath, 1930

601

602 Material: Five specimens – PNRL.1835 (Fig. 10q), PNRL.1839 (Fig. 10r), PNRL.1840 (Fig. 10s), PNRL.1841 (Fig. 10t), and PNRL.1842 (Fig. 10u) from Clavaillan.

604 Description: Pyritic material composed of small-sized phragmocones with two fragmented
605 (PNRL.1841 and PNRL.1842) and three, almost complete specimens (PNRL.1835,
606 PNRL.1839 and PNRL.1840). Up to 6 mm, the shape of the inner whorls is sub-oval to sub-
607 rounded, with a sub-tabulate venter covered by a smooth siphonal band that can extend up to a
608 diameter of 18 mm. Above this diameter, the section is subrectangular, narrow and
609 compressed, with a maximum thickness in the lower third of the flanks. The ornamentation is
610 composed of slightly sigmoid ribs, firstly prorsiradiate on the lower third, they bend slightly
611 backward on the flank. Primary ribs originate from the umbilical margin, while between each
612 pairs of primaries, a flexuous secondary rib appears in the middle or in the lower third of the
613 flank. The ornamentation is composed of very fine and dense primary and secondary ribs,
614 then beyond 18 mm in diameter, the ribs are more spaced and become stronger. Above this
615 diameter, all ribs cross the venter regularly.

616 Discussion: *Deshayesites grandis* is a late member of the genus *Deshayesites* which is
617 considered as the sub-zonal index species of the upper *D. deshayesi* Zone (*D. grandis*
618 Subzone) following its introduction in the Lower Greensand (Casey, 1963; Casey et al.,
619 1998). The material at our disposal is similar to those from Clavaillan collected by Dutour
620 (2005, p. 190, pl. 29, fig. 5a-f, 6a-d, 7a-c, 8a-f, 9a-d) and also referred to *D. grandis*. Bersac
621 & Bert (2012, p. 241) expressed doubt about the specific assignment of the Dutour's
622 specimens since their small size "does not allow observing either the disappearance diameter
623 of the latero-ventral tubercles nor the subtabulate ventral area". Our largest specimen shows
624 the flattening of the ventral area in the adult whorl but it does not develop tubercles in the
625 peri-ventral area. Such forms were considered as intermediary between typical *D. deshayesi*
626 and *D. grandis* and were subsequently referred to *D. multicostatus* Swinnerton, 1935 by
627 Bersac & Bert (2012). However, the type material of *D. multicostatus* does not allow the
628 study of its juvenile whorls and it originates from polyzonal condensed beds of late early
629 Aptian age (Casey, 1964). As a consequence, the supposed linear evolution between *D.*
630 *deshayesi* and *D. grandis* remains unclear and its record in a best-developed ammonite
631 succession still remains to be documented. We thus tentatively refer the Clavaillan population
632 to early members of *D. grandis* pending a detailed revision.

633

634 Genus *Dufrenoyia* Kilian & Reboul, 1915

635

636 *Dufrenoyia dufrenoyi* (d'Orbigny, 1841)

637

638 Material: The single specimen PNRL.1828 (Fig. 10v-w) from Les Rabots.

639 Description: Small-sized phragmocone of a deshayesitid form. It is characterized by a
640 compressed, higher than wide, trapezoidal whorl section with a sub-tabulate venter through its
641 visible ontogeny. The ornamentation of the inner whorls is composed of rigid and dense ribs
642 which progressively gives way to a regular alternance of flexuous primary and intercalate
643 ribs. The ribs end on the venter as latero-ventral tubercles which take the form of small clavi
644 as growth increases. The ribs are progressively enlarged and the venter is flat throughout the
645 last preserved whorl.
646 Discussion: The specimen PNRL.1826.5 matches well the neotype of *D. dufrenoyi* designated by Dutour (2005). According to the latter author, *D. dufrenoyi* can be distinguished from its supposed direct ancestor *D. praedufrenoyi* Casey, 1963 by a latter disappearance of the smooth ventral band. Given the intraspecific variability, this features does not deserve a valid specific rank, and Bersac & Bert (2012) thus considered *D. praedufrenoyi* as a junior subjective synonym of *D. dufrenoyi*. In the current state of the literature, *D. dufrenoyi* group ranges through the upper part of the *D. furcata* Zone (*D. dufrenoyi* Subzone).

653

654 Superfamily Douvilleiceratoidea Parona & Bonarelli, 1897

655 Family Douvilleiceratidae Parona & Bonarelli, 1897

656 Subfamily Douvilleiceratinae Parona & Bonarelli, 1897

657 Genre *Procheloniceras* Spath, 1923

658

659 *Procheloniceras* sp.

660

661 Material: Six specimens – PNRL.1821 (Fig. 9g-h) and PNRL.1826 (Fig. 9i-j) from les Rabots; PNRL.1822 (Fig. 9k-l) from La Jaumière; PNRL.1820 (Fig. 9a-b), PNRL.1824 (Fig. 9c-d) and PNRL.1823 (Fig. 9e-f) from Murs (Sumian ravine).

664 Description: Small-sized juveniles and large adult body chambers of *Procheloniceras*. Their whorl section is depressed, sub-oval with a steep oblique umbilical wall. The ornamentation is composed of radial primary ribs with two lateral thickenings. The peri-ventral one is enlarged and take the form of a discrete spiny tubercles. Generally, one to two atuberculate intercalate and large, bifurcate ribs join on the peri-ventral tubercles. All ribs cross the venter regularly.
665
666
667
668
669 The medium-sized specimen PNRL.1824 shows the adult ornamentation with slightly rectiradiate ribs. On the large-sized specimen PNRL.1820, the section is markedly depressed.
670
671 The ornamentation is composed of straight, radial and spaced ribs marked by the alternation
672 between main and secondary ribs that sometimes join on the peri-umbilical margin.

673 Discussion: The poorly preserved state of preservation of our specimens prevents us from a
674 specific assignment. Moreover, the taxonomy and stratigraphic occurrence of the early Aptian
675 *Procheloniceras* Spath – *Cheloniceras* Hyatt lineage still remains unclear and prevent further
676 comparison with our material.

677

678 Superfamily Ancyloceratoidea Gill, 1871

679 Family Ancyloceratidae Gill, 1871

680 Genus *Ammonitoceras* Dumas, 1876

681

682 *Ammonitoceras* sp.

683

684 Material: Four fragmented specimens – PNRL.1819 (Fig. 9m-n) from La Jaumière;
685 PNRL.1817 (Fig. 9o-p), PNRL.1818 (Fig. 9q-r) and PNRL.1827 (Fig. 10x-y) from Les
686 Rabots.

687 Description: Small-sized fragments of inner spire. The whorl section is depressed, sub-oval to
688 coronate. The ornamentation is composed of two tubercles, whose peri-ventral one is enlarged
689 as growth increases, and take the form of an elongated clavi, perpendicular to the axis of the
690 coil. Irregular bundles of, at least, three ventral ribs are joined on the latero-ventral tubercles
691 while atuberculate, fine ribs are intercalated. All ribs cross the venter regularly.

692 Discussion: The poorly-preserved specimens at our disposal are doubtfully referred to the
693 genus *Ammonitoceras*. It should be noted that the inner whorls of, the only known, type
694 specimen of *A. u cetiae* are not preserved and this prevents further comparison with the
695 juvenile forms at our disposal. According to Delanoy & Conte (2011), the age of *A. u cetiae*
696 remains unclear in its type locality, but it can be dated to the uppermost *D. forbesi* or *D.*

697 *deshayesi* Zone.

698

699 Ancyloceratidae gen. et sp. indet.

700

701 Material: An incomplete spire PNRL.1814 (Fig. 10a-b) from La Jaumière section.

702 Description: The specimen corresponds to a fragment of a large-sized spire of an

703 ancyloceratid ammonite. The whorl section is sub-oval, higher than wide with an arched

704 dorsum. The ornamentation is composed of fine, dense, moderately straight ribs. Every 5-6

705 ribs, a row of peri-umbilical and peri-ventral tubercles are intercalated, to which several ribs

706 can be joined.

707 Discussion: By its state of preservation, the generic and specific assignment of the specimen

708 remains unclear. Nevertheless, the ornamentation of the spire at our disposal is close to the

709 type specimen of *Sarkariceras thomeli* Vermeulen. The age of this species is presumably

710 older since it originates from the topmost Calcaires Barrémo-Bédouliens Fm. of the Combe-

711 Lambert basinal section dated to the transition between the *D. oglanlensis* (pro. *D.*

712 *tuarkyricus*) Zone and *D. forbesi* (pro *D. weissi*) Zone (Delanoy, 1995).

713

714 Family Acrioceratidae Vermeulen, 2004

715 Genus *Toxoceratoides* Spath, 1924

716

717 *Toxoceratoides* aff. *royeri* (d'Orbigny, 1842)

718

719 Material: Specimen PNRL.1815 (Fig. 10c-d).
Description: Toxoceratid body-chamber with a slightly arcuate proversum and a moderately long retroversum. The whorl section is sub-hexagonal to subrounded as growth increases. The phragmocone ends on the middle part of the proversum. Two ornamental stages are observed and composed of (i) regular alternation of trituberculate primary ribs and atuberculate intercalatories on the proversum and lower part of the flexus; and (ii) coarse and spaced single ribs on the retroversum that cross the venter. Ribs can be joined on small tubercles on the dorsal shoulder.

Discussion: The specimen at our disposal is intermediate between *T. royeri* and *T. rochi* Casey, 1961. It differs from the type specimen of *T. royeri* by the lack of a ventral furrow delimited by small spiny peri-ventral tubercles and the later disappearance of the sub-adult ornamental stage. A younger age (*D. deshayesi* Zone) is commonly assigned to *T. royeri*, but its precise horizon remains unclear due to the lack of continuous outcrops in its type area and poor biostratigraphic dating of its type stratum, i.e. Marnes à Plicatules Fm. (Bulot et al., 2017). *Toxoceratoides rochi* Casey can be easily distinguished from our specimen by its strong latero-ventral clavi through its sub-adult stage (Frau et al., 2017). The species is younger than our specimen since it ranges in the *D. deshayesi–D. furcata* zones interval.

Superfamily Desmoceratoidea Zittel, 1895

Family Aconeceratidae Spath, 1923

Genus *Aconeceras* Hyatt, 1903

*Aconeceras nisus* (d'Orbigny, 1841)

Material: The single specimen PNRL.1829 (Fig. 10z) from Les Rabots.
744 Description: The specimen corresponds to a small-sized phragmocone of an involute oxycone
745 ammonite with gently convex flanks. The umbilical region exhibits a low wall. The
746 ornamentation is smooth.

747 Discussion: *Aconeceras nisus*, to which our specimen is referred, reaches its acme in the *D. furcata* Zone in the Apt-Gargas area, where it represents more than half of the ammonite assemblage (Dutour, 2005). Its record below the *D. furcata* Zone remains poorly understood due to the scarcity of ammonites below the *D. furcata* Zone in the Vocontian Basin (Dutour, 2005).

752

753 References

754

755 Arnaud-Vanneau, A., Arnaud, H., Charollais, J., Conrad, M.A., Cotillon, P., Ferry, S., Masse, J.-P., Peybernès, B., 1979. Paléogéographie des calcaires urgoniens du sud de la France. Géobios Mémoire Special 3, 363-383.

758 Baudouin, C., Delanoy, G., Moreno-Bedmar, J.A., Pictet, A., Vermeulen, J., Conte, G., 1959. Gonnet, R., Boselli, P., Boselli, M., 2016. Revision of the genera *Heminautilus* Spath, 1927 and *Josanautilus* Martínez & Grauges, 2006 (Nautilida, Cenoceratidae). Carnets de Géologie, CG2016_A05, pp. 61-212.

762 Bersac, S., Bert, D., 2012. Ontogenesis, variability and evolution of the Lower Greensand 763 Deshayesitidae (Ammonoidea, Lower Cretaceous, Southern England): reinterpretation 764 of literature data; taxonomic and biostratigraphic implications. Annales du Muséum 765 d'Histoire Naturelle de Nice 27, 197-270.

766 Bulot, L.G., Frau, C., Pictet, A., 2017. Revision of *Toxoceratoides royeri* (d'Orbigny, 1842) 767 and its bearing on the systematics of the Aptian Acrioceratidae Vermeulen, 2004 768 (Ammonoidea, Ancyloceratina, Ancyloceratoidea). Cretaceous Research, in press.
769 Casey, R., 1961. Casey, R., 1961. A monograph of the Ammonoidea of the Lower
770 Greensand-Part II. Palaeontographical Society, 45-118.

771 Casey, R., 1964. A monograph of the Ammonoidea of the Lower Greensand, part V.
772 Palaeontographical Society, 289-398.

773 Casey, R., Bayliss, H.M., Simpson, M.I., 1998. Observations on the lithostratigraphy and
774 ammonite succession of the Aptian (Lower Cretaceous) Lower Greensand of Chale Bay,
775 Isle of Wight, UK. Cretaceous Research 19, 511-535.

776 Conte, G., 1999. Éléments de la faune de l'Aptien inférieur (Bédoulien) de Serviers-la-
777 Baume (Gard). Bulletin de la Société d'Étude des Sciences Naturelles de Nîmes et du
778 Gard 62, 11-15.

779 Delanoy, G., 1995. About some significant Ammonites from the Lower Aptian (Bedoulian) of
780 the Angles-Barrême area (South-East of France). In: Cecca F. (ed.), Proceeding of 3rd
781 Workshop on Early Cretaceous Cephalopods. Memorie descrittive della Carta
782 Geologica d'Italia, Roma, 51, 65-101.

783 Delanoy, G., Conte, G. 2011. Revision of the holotype of *Ammonitoceras u cetiae* Dumas,
784 1876 (Ammonoidea, Ancyloceratina). Annales du Muséum d'Histoire Naturelle de
785 Nice, 26, 9-16.

786 Dumas, E., 1876. Statistique géologique, minéralogique, métallurgique et paléontologique du
787 Département du Gard. Deuxième partie, constitution géologique, 695 p.

788 Dutour, Y., 2005. Biostratigraphie, évolution et renouvellements des ammonites de l'Aptien
789 supérieur (Gargasien) du bassin vocontien (Sud-Est de la France). Thèse de l'Université
790 Claude Bernard-Lyon 1, 302 pp.

791 Eaton, A.D., Clesceri, L.S., Greenberg, A.E., 1995. Standard methods for the examination of
792 water and wastewater. New York. 19th edition. American Public Health Association,
793 pp. 4113-4114.
794 Fitton, W.H., 1847. A stratigraphical account of the section from Atherfield to Rocken End,
795 on the South-west coast of the Isle of Wight. The Quarterly Journal of the Geological
796 Society of London 3, 289-327.

797 Föllmi, K.B., Gainon, F., 2008. Demise of the northern Tethyan Urgonian carbonate platform
798 and subsequent transition towards pelagic conditions: the sedimentary record of the Col
799 de la Plaine Morte area, central Switzerland. Sedimentary Geology 205, 142-159.

800 Frau, C., Delanoy, G., Hourqueig, E. (2015). Le genre *Macroscaphites* Meek, 1876
801 (Ammonoidea) dans l'Aptien inférieur de Cassis-La Bédoule (Bouches-du-Rhône,
802 France). Proposition d'un nouveau schéma zonal pour la série stratotypique. Revue de
803 Paléobiologie 34, 45-57.

804 Frau, C., Delanoy, G., Masse, J.-P., Lanteaume, C., Tendil, A.J.B. 2016. New Heteroceratidae
805 (Ammonoidea) from the late Barremian drowning succession of Marseille (Bouches-du
806 Rhône, France). Acta Geologica Polonica 66, 205-225.

807 Frau, C., Bulot, L.G., Delanoy, G., 2017. New and poorly known Aptian Acrioceratidae
808 (Ancyloceratoidea, Ammonoidea) from Cassis (Bouches-du-Rhône). Neues Jahrbuch
809 für Geologie und Paläontologie Abhandlungen 238, 335-346.

810 Frau, C., Masse, J.-P., Fenerci-Masse, M., submitted. Is Strontium isotope stratigraphy a
811 reliable tool for dating the Barremian – Aptian transition in shallow water carbonate
812 settings? Neues Jahrbuch für Geologie und Paläontologie.

813 Gauthier, H., Busnardo, R., Combémorel, R., Delanoy, G., Fischer, J.-C., Guérin-Franiatte,
814 S., Joly, B., Kennedy, W.J., Sornay, J., Tintant, H. 2006. Volume IV. Céphalopodes
815 crétacés, p. 1-292. In: Fischer, J.-C., (Ed.), Révision critique de la Paléontologie
816 Française d'Alcide d'Orbigny. Backhuys Publishers BV, Leiden. 292+662 pp.

817 Gill, T., 1871. Arrangement of the families of mollusks. Smithsonian Miscellaneous
818 Collections 227, xvi + 1-49.
819 Gröcke, D.R., Hesselbo, S.P., Jenkyns, H.C., 1999. Carbon-isotope composition of lower Cretaceous fossil wood: ocean-atmosphere chemistry and relation to sea-level change. Geology 27, 155-158.

820
821
822 Huck, S., Heimhofer, U., Rameil, N., Bodin, S., Immenhauser, A., 2011. Strontium and carbon-isotope chronostratigraphy of Barremian-Aptian shoal-water carbonates: Northern Tethyan platform drowning predates OAE 1a. Earth Planetary Sciences Letters 304, 547-558.

826 Hyatt, A., 1900. Cephalopoda. In: Zittel, von K. (ed.), Textbook of Palaeontology, English ed., translated by C.R. Eastman. Macmillan. London & New York; 502-592.

828 Hyatt, A., 1903. *Pseudoceratites* of the Cretaceous. Monographs of the United States Geological Survey 44, 352 p.

830 Immenhauser, A., Holmden, C., Patterson, W.P., 2008. Interpreting the carbon isotope record of ancient shallow epeiric seas: lessons from the Recent. In: Pratt, B.R., Holmden, C. (Eds.), Dynamics of Epeiric Seas, Geological Association of Canada Special Publication, pp. 135-174.

834 Joachimski, M.M., 1994. Subaerial exposure and deposition of shallowing upward sequences: evidence from stable isotopes of Purbeckian peritidal carbonates (basal Cretaceous), Swiss and French Jura mountains. Sedimentology 41, 805-824.

837 Joseph, P., Cabrol, C., Fries, G., 1987. Blocs basculés et passes sous-marines dans le Champ de fractures de Banon (France, SE) à l'Apto-Albien: une paléotopographie directement contrôlée par la tectonique synsédimentaire décrochante. Comptes Rendus de l'Académie des Sciences 304, 447-452.

841 Joseph, P., Beaudouin, B., Fries, G., Parize, O., 1989. Les vallées sous-marines enregistrent au Crétacé inférieur le fonctionnement en blocs basculés du domaine vocontien. Comptes-rendus de l'Académie des Sciences de Paris 309, 1031-1038.
844 Kandel, D., 1992. Analyse paléotectonique de la plate-forme méridionale du bassin vocontien et de ses bordures, durant l'intervalle Barrémo-Albien (Ventoux-Lure-Baronnies, chaînes subalpines méridionales, France). Thèse de l'Université Pierre et Marie Curie - Paris VI, 318 pp.

848 Kazansky, P., 1914. Description d'une collection des Céphalopodes des terrains Crétacés du Daghestan. Tomsk. 127 p.

850 Kilian, W., 1887. Système Crétacé. Annuaire géologique de l' Université 3, 299-356.

851 Kilian, W., Reboul, P., 1915. Contribution à l'étude des faunes paléocrétacées du Sud-Est de la France. I. La faune de l'Aptien inferieur des environs de Montélimar (Drôme). II. Sur quelques ammonites de l'Hauterivien de la Bégude (Basses Alpes). Mémoires pour Servir à l'Explication de la Carte géologique Détaillée de la France, 288 p.

855 Korbar, T., Glumac, B., Cvetko Tešović, B., Cadieux, S.B., 2012. Response of a carbonate platform to the Cenomanian-Turonian drowning and OAE 2: a case study from the Adriatic Platform (Dalmatia, Croatia). Journal of Sedimentary Research 82, 163-176.

858 Leenhardt, F. 1883. Étude géologique de la région du Mont-Ventoux. Thèse, Montpellier, 273 p.

860 Léonide, P., Borgomano, J., Masse, J.-P., Doublet, S., 2012. Relation between stratigraphic architecture and multi-scale heterogeneities in carbonate platforms. The Barremian-Lower Aptian of the Monts de Vaucluse, SE France. Sedimentary Geology 82, 499-520.

864 Léonide, P., Fournier, F., Reijmer, J.G., Vonhof, H., Borgomano, J., Dijk, J., Rosenthal, M., van Goethem, M., Cochard, J., Meulenaars, K., 2014. Diagenetic patterns and pore space distribution along a platform to outer-shelf transect (Urgonian limestone, Barremian-Aptian, SE France). Sedimentary Geology 306, 1-23.
868 Linder, P., Gigandet, J., Hüsser, J.-L., Gainon, F., Föllmi, K.B., 2006. The Early Aptian
869 Grünten Member: description of a new lithostratigraphic unit of the helvetic Garschella
870 Formation. Eclogae Geologicae Helvetiae 99, 327–341.

871 Masse, J.-P., 1976. Les calcaires urgoniens de Provence (Valanginien-Aptien inférieur).
872 Stratigraphie, paléontologie, les paléoenvironnements et leur évolution. Thèse
873 Université Aix-Marseille-II, 445 pp.

874 Masse, J.-P., 1993. Valanginian to early Aptian carbonate platforms from Provence (SE
875 France). In: Simo, A., Scott, R.W., Masse, J.-P. (Eds.), Cretaceous Carbonate Platforms.
876 American Association of Petroleum Geologists, Memoir 5, 363–374.

877 Masse, J.-P., 1995. Lower Cretaceous biostratigraphy of southern France. A reference for
878 Mesogean correlations. Revista Mexicana de Ciencias Geológicas 12, 236–256.

879 Masse, J.-P., Fenerci-Masse, M., 2011. Drowning discontinuities and stratigraphic correlation
880 in platform carbonates. The late Barremian-early Aptian record of southeast France.
881 Cretaceous Research 32, 659–684.

882 Masse, J.-P., Fenerci-Masse, M., 2013a. Drowning events, development and demise of
883 carbonate platforms and controlling factors: The Late Barremian-Early Aptian record of
884 Southeast France. Sedimentary Geology 298, 28–52.

885 Masse, J.-P., Fenerci-Masse, M., 2013b. Stratigraphic updating and correlation of late
886 Barremian–early Aptian Urgonian successions and their marly cover, in their type
887 region (Orgon-Apt, SE France). Cretaceous Research 39, 17–28.

888 Masse, J.-P., Philip, J., 1976. Paléogéographie et tectonique du Crétacé moyen en Provence:
889 révision du concept d'isthme durancien. Revue de Géographie physique et de Géologie
890 dynamique 18, 49–66.
891 Masse, J.-P., El Albani, A., Erlenkeuser, H., 1999. Isotope stratigraphy (δ¹³C) of the Lower Aptian from Provence (S.E. France): application to platform/basin correlations. *Eclogae Geologicae Helvetiae* 92, 259–263.

894 Masse, J.-P., et al., 2000. Early Aptian. In: Dercourt, J., Gaetani, M., and contributors (Eds.), *Atlas Peritethys, Palaeogeographical Maps*. CCGM/CGMW, Paris, Map.

896 Menegatti, A.P., Weissert, H., Brown, R.S., Tyson, R.V., Farrimond, P., Strasser, A., Caron, M., 1998. High-resolution δ¹³C stratigraphy through the early Aptian “Livello Selli” of the Alpine Tethys. *Paleoceanography* 13, 530–545.

899 Moullade, M., Tronchetti, G., Balme, C., Kouyoumontzakis, G., 2006. The Gargasian (Middle Aptian) of La Tuilière - St-Saturnin-lès-Apt (area of the Aptian historical stratotype, Vaucluse, SE France): geographic setting and outcrop correlation. *Carnets de Géologie, Article 2006/01*, 7 p.

903 Moullade, M., Tronchetti, G., Bellier, J.-P., 2008. Associations et biostratigraphie des Foraminifères benthiques et planctoniques du Bédoulien sommital et du Gargasien inférieur de La Tuilière e St-Saturnin-lès-Apt (aire stratotypique de l’Aptien, Vaucluse, SE France). *Carnets de Géologie, Article 2008/01*, 50 p.

907 Moullade, M., Tronchetti, G., Babinot, J.-F., 2009. Le Gargasien de Gargas (Vaucluse, SE de la France): Synthèse des données de terrain et révision de la microfaune de foraminifères et d'ostracodes. *Carnets de Géologie, Article 2009/10*, 15 p.

910 Moullade, M., Tronchetti, G., Balme, C., Mauroux, P., 2012. A new upper Bedoulian section in the Aptian stratotypic area: Croagnes (5 km NW of Gargas, Vaucluse, SE France). *Carnets de Géologie, Letter 2012/03*, pp. 193-199.

913 Moullade, M., Tronchetti, G., Granier, B., Bornemann, A., Kuhnt, W., Lorenzen, J. 2015. High-resolution integrated stratigraphy of the OAE1a and enclosing strata from core
915 drillings in the Bedoulian stratotype (Roquefort-La Bédoule, SE France). Cretaceous
916 Research 56, 119-140.

917 Moreno-Bedmar, J.A., Company, M., Bover-Arnal, T., Salas, R., Delanoy, G., Martínez, R.,
918 Grauges, A., 2009. Biostratigraphic characterization by means of ammonoids of the
919 lower Aptian Oceanic Anoxic Event (OAE 1a) in the eastern Iberian Chain (Maestrat
920 Basin, eastern Spain). Cretaceous Research 30, 864-872.

921 Moreno-Bedmar, J.A., Company, M., Sandoval, J., Tavera, J.M., Bover-Arnal, T., Salas, R.,
922 Delanoy, G., Maurrasse, F.J.-M.R., Martínez, R., 2012. Lower Aptian ammonite and
923 carbon isotope stratigraphy in the eastern Prebetic Domain (Betic Cordillera,
924 southeastern Spain). Geologica Acta 10, 333-350.

925 Najarro, M., Rosales, I., Moreno-Bedmar, J.A., de Gea, G.A., Barrón, E., Company, M.,
926 Delanoy, G., 2011. High-resolution chemo- and biostratigraphic records of the Early
927 Aptian oceanic anoxic event in Cantabria (N Spain): Palaeoceanographic and
928 palaeoclimatic implications. Palaeogeography, Palaeoclimatology, Palaeoecology 299,
929 137-158.

930 Orbigny, d' A., 1840-1842. Paléontologie française, Description zoologique et géologique de
tous les animaux mollusques et rayonnés fossiles de France. Terrains Crétacés, Vol. 1.
931
932 Céphalopodes. Masson, Paris 662 pp.

933 Orbigny, d' A., 1850. Prodrome de Paléontologie stratigraphique universelle des animaux
934 mollusques & rayonnés, faisant suite au cours élémentaire de paléontologie et de
935 géologie stratigraphiques. Vol. 2. Masson. Paris, 427 p.

936 Parona, C.F., Bonarelli, G., 1897. Fossili Albiani d'Escragnolles, del Nizzardo e della Liguria
937 occidentale. Paleontologica italiana 2, 53-112.
938 Pictet, A., Delanoy, G., 2017. The Chabert Formation – a newly defined stratigraphic unit of
939 late early Aptian age in the southern Ardèche, SE France. Archives des Sciences 69, 3–
940 28.

941 Pictet A., Delanoy G., Adatte T., Spangenberg J.E., Baudouin C., Boselli P., Boselli M.,
942 Föllmi, K.B., 2015. Three successive phases of platform demise during the early Aptian
943 and their association with the oceanic anoxic Selli episode (Ardèche, France).
944 Palaeogeography, Palaeoclimatology, Palaeoecology 418, 101–125.

945 Reboulet, S., Giraud, F., Proux, O., 2005. Ammonoid abundance variations related to changes
946 in trophic conditions across the oceanic anoxic event 1d (latest Albian, SE France).
947 Palaios 20, 121–141.

948 Reboulet, S., Rawson, P.F., Moreno-Bedmar, J.A., Aguirre-Urreta, M.B., Barragán, R.,
949 Bogomolov, Y., Company, M., González-Arreola, C., Idakieva Stoyanova, V.,
950 Lukeneder, A., Matrion, B., Mitta, V., Randrianaly, H., Vašíček, Z., Baraboshkin, E.J.,
951 Bert, D., Bersac, S., Bogdanova, T.N., Bulot, L.G., Latil, J.-L., Mikhailova, I.A.,
952 Ropolo, P., Szives, O., 2011. Report on the 4th International Meeting of the IUGS
953 Lower Cretaceous Ammonite Working Group, the “Kilian Group” (Dijon, France, 30th
954 August 2010). Cretaceous Research 32, 786–793.

955 Reboulet, S., Szives, O., Aguirre-Urreta, B., Barragán, R., Company, M., Idakieva, V.,
956 Ivanov, M., Kakabadze, M.V., Moreno-Bedmar, J.A., Sandoval, J., Baraboshkin, E.J.,
957 Çağlar, M.K., Főzy, I., González-Arreola, C., Kenjo, S., Lukeneder, A., Raisossadat,
958 S.N., Rawson, P.F., Tavera, J.M., 2014. Report on the 5th International Meeting of the
959 IUGS Lower Cretaceous Ammonite Working Group, the Kilian Group (Ankara,
960 Turkey, 31st August 2013). Cretaceous Research 50, 126–137.
961 Ropolo, P., Gonnet, R., 2003. Les Dufrenoyia (*Ammonoidea*) de la zone à Furcata (Aptien inférieur) du Sud Est de la France. *Annales du Muséum d'Histoire Naturelle de Nice* 18, 21-57.

964 Ropolo, P., Conte, G., Gonnet, R., Masse, J.P., Moullade, M., 2000. Les faunes d'Ammonites du Barrémien supérieur/Aptien inférieur (Bédoulien) dans la région stratotypique de Cassis-La Bédoule (SE France): état des connaissances et propositions pour une zonation par Ammonites du Bédoulien-type. *Géologie Méditerranéenne*. 25 (1998), 167-175.

969 Ropolo, P., Moullade, M., Gonnet, R., Conte, G., 2006. The Deshayesitidae Stoyanov, 1949 (*Ammonoidea*) of the Aptian stratotype region at Cassis-La Bédoule (SE France). *Notebooks on Geology* (Memoir 2006/01 (CG22006_M01), 46 pp.

972 Ropolo, P., Moullade, M., Conte, G., Tronchetti, G., 2008a. About the stratigraphic position of the Lower Aptian *Roloboceras hambrovi* (*Ammonoidea*) level. *Notebooks on Geology, Letter 2008/03* (CG2008_L03), 7 pp.

975 Ropolo, P., Conte, G., Moullade, M., Tronchetti, G., Gonnet, R., 2008b. The Douvilleiceratidae (*Ammonoidea*) of the Lower Aptian historical stratotype area at Cassis-La-Bédoule (SE France). *Notebooks on Geology, Memoir 2008/03* (CG22008_M03), 60 pp.

979 Spath, L.F., 1923. A monograph of the Ammonoidea of the Gault (1923-1943), part I. *Palaeontographical Society (1921)*, 1-72.

981 Spath, L.F., 1924. On the ammonites of the Speeton Clay and the subdivisions of the Neocomian. *Geological Magazine* 61, 73-89.

983 Spath, L.F., 1930. On some Ammonoidea from the Lower Greensand. *The Annals and Magazine of Natural History* 5, 417-464.
985 Stoyanow, A. 1949. Lower Cretaceous stratigraphy in southern Arizona. Geological Society
986 of America Memoir, 38, 169 p.

987 Swinnerton, H., 1935. The rocks below the Red Chalk of Lincolnshire and their cephalopod
988 fauna. Quaternary Journal of the Geological Society 91, 1-46.

989 Triat, J.-M., 1983. Paléoaltérations dans le Crétacé supérieur de Provence rhodanienne. Thèse
990 de l'Université Louis Pasteur-Strasbourg, 202 pp.

991 Triat, J.-M., 1985. Étude géologique et minéralogique des gisements d'ocres du Pays d'Apt.
992 Association vauclusienne pour le développement de la géologie provençale, Apt, 140 p.

993 Vermeulen, J., 2004. Vers une nouvelle classification à fondement phylogénétique des
994 ammonites hétéromorphes du Crétacé inférieur méditerranéen. Le cas des
995 Crioceratitidae Gill, 1871, nom. correct. Wright 1952, des Emericiceratidae fam. nov. et
996 des Acrioceratidae fam. nov. (Ancylocerataceae Gill, 1871). Riviéra Scientifique 88,
997 69-92.

998 Zittel, K.A. Von, 1884. Handbuch der Paläontologie. Abt. 1. Band II. Munich: Oldenbourg.
999 329-522 pp.

1000 Zittel, K.A. Von, 1895. Grundzüge der Paläontologie (Paläozoologie). Munich and Leipzig,
1001 vii + 972 pp.

1002

1003 Figure legends

1004

1005 Fig. 1. Lithostratigraphy (U¹ to U³), discontinuities (D1 to D4) and palaeogeography of the
1006 North Provence Urgonian-type carbonate platform and its marly cover (A¹ to A³) (modified
1007 from Masse & Fenerci-Masse, 2011, 2013; Léonide et al., 2012).

1008
Fig. 2. A - Studied localities of the Apt-Rustrel area (Vaucluse, SE France) and B - simplified geological map of the lithostratigraphic units of the North Provence platform series. The numbers correspond to the studied localities (decimal geographic coordinates) - 1-3: La Jaumière (5°23'24"E/43°93'62"N); Sumian (5°14'09"E/43°56'31"N); and Les Rabots (5°25'47"E/43°94'50"N); 4: Clavaillan (5°27'51"E/43°92'00"N); 5: Croagnes (5°32'91"E/43°94'06"N); 6: Rustrel (5°48'47"E/43°92'65"N).

1015

Fig. 3. Litho-log of the Les Rabots-La Jaumière-Sumian ravines with ammonite occurrences and geochemistry samples. A - Panorama view of the D3 discontinuity sensu Masse & Fenerci-Masse (2011) at La Jaumière, which marks the demise of the North Provence platform; B - Quartz-rich spongolithic packstone facies of the first limestone bundle of the A¹ unit; C & D - Close-up views of the D4 discontinuity sensu Masse & Fenerci-Masse (2011), note the *Thalassinoides* furrows infilled with glauconite-rich sands.

1022

Fig. 4. Litho-log of the Croagnes section. A - General view of the lower part of the A¹ unit at the locality studied by Moullade et al. (2012); B - Close-up view of the D4 discontinuity sensu Masse & Fenerci-Masse (2011), which is capped by irregular, 20cm-thick glauconite-rich sandy marls which grades into blue-grey muddy marls of the A² unit.

1027

Fig. 5. Litho-log of the Rustrel section with ammonite occurrences and geochemical samples. A - Panorama view of the D3 and D4 discontinuities reinterpreted from Masse & Fenerci-Masse (2011); B - Close-up views of the D4 discontinuity; C - Close-up views on the *Thalassinoides* furrows infilled with glauconite-rich sands topping the D4 discontinuity.

1032
Fig. 6. Litho-log of the Clavaillan section with ammonite occurrences and panorama view of the lower part of the blue-grey muddy marls of the A² unit.

1035

Fig. 7. Comparison between the Mediterranean standard ammonite scale for the Barremian/Aptian boundary interval (Reboulet et al., 2014) and the Ropolo et al. (2006, 2008a-b) zonation. The grey bar marks the culmination of the OAE 1a-related black shales associated to the C3 (pro parte) to C6 carbon segments sensu Menegatti et al. (1998).

1040

Fig. 8. Selected Deshayesitidae from the post-Urgonian A¹ unit of the Murs–Joucas area, Vaucluse; (a-b) *Deshayesites cf. kiliani* (Spath), PNRL.1808; (b-c) *Deshayesites cf. forbesi* Casey, PNRL.1800; (e-f) *Deshayesites cf. euglyphus* Casey, PNRL.1803; (g-h) *Deshayesites cf. euglyphus* Casey, PNRL.1832; (i-j) *Deshayesites* sp., PNRL.1834; (k-l) *Deshayesites* sp., PNRL.1805; (m-n) *Deshayesites cf. euglyphus* Casey, PNRL.1804. Scale bar is 10mm.

1046

Fig. 9. Selected Douvilleiceratidae and Ancyloceratidae from the post-Urgonian A¹ unit of the Murs–Joucas area, Vaucluse; *Procheloniceras* sp., (a-b) PNRL.1820, (c-d) PNRL.1824, (e-f) PNRL.1823, (g-h) PNRL.1821, (i-j) PNRL.1826, (k-l) PNRL.1822; and *Ammonitoceras* sp., (m-n) PNRL.1819, (o-p) PNRL.1817, (q-r) PNRL.1818. Scale bar is 10mm.

1051

Fig. 10. Selected ammonites from the post-Urgonian A¹ unit of the Murs–Joucas (a-d, g-j, m-p) and Rustrel (e-f, k-l) areas, and A² unit of Clavaillan (q-u) and Les Rabots (v-z), Vaucluse; (a-b) Ancyloceratidae gen. et sp. indet, PNRL.1814; (c-d) *Toxoceratoides* aff. *royeri* (d'Orbigny), PNRL.1815; (e-f) *Pseudohaploceras* sp., PNRL.1834, (g-h) *Pseudohaploceras* sp., PNRL.1809; (i-j) *Pseudohaploceras* sp., PNRL.1810; (k-l) *Pseudohaploceras* sp., PNRL.1833; (m-n) *Pseudohaploceras* sp., PNRL.1811; (o-p) *Pseudohaploceras* sp.,
1058 PNRL.1812; *Deshayesites grandis* Spath (q) NRL.1811; (r) PNRL.1839, (s) PNRL.1840, (t)
1059 PNRL.1841, (u) PNRL.1842; (v-w) *Dufrenoyia dufrenoyi* (d'Orbigny), PNRL.1828; (x-y)
1060 *Ammonitoceras* sp., PNRL.1827; (z) *Aconeceras nisus* (d'Orbigny), PNRL.1829. Scale bar is
1061 10mm.

1062

1063 Fig. 11. Stable isotopes (δ¹³Ccarb and δ¹⁸Ocarb) and phosphorus (P) content of the Les Rabots-
1064 Sumian-La Jaumière section. Cross-plots of the stable isotopes vs. phosphorus content show
1065 high variance with strong correlation coefficient.

1066

1067 Fig. 12. Stable isotopes (δ¹³Ccarb and δ¹⁸Ocarb) and phosphorus (P) content of the Rustrel
1068 section. Cross-plots of the stable isotopes vs. phosphorus content show low to medium
1069 correlation coefficient.

1070

1071 Fig. 13. Understanding of the lower Aptian *Deshayesites forbesi* Zone between its British
1072 original definition (Casey et al., 1998), Mediterranean standard zonation (Reboulet et al.,
1073 2014) and this work. The succeeding acmes of *Roloboceras* spp. and *Megatyloceras* spp.
1074 herein define the *Roloboceras hambrovi* Subzone.

1075

1076 Fig. 14. Revised litho- and biostratigraphic correlations between the Bas-Vivarais and North
1077 Provence platform successions and the Bedoulian-type series of the South Provençal Basin.
1078 The D1 to D4 discontinuities are correlated by black lines and calibrated with the
1079 Mediterranean standard zonation applied to the Bedoulian-type series (Frau et al, 2015).
<figure><img src="image_3.png" /></figure>

<figure><img src="image_4.png" /></figure>

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Cherty-bioclastic facies

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Bioclastic-oolitic facies

<figure><img src="image_11.png" /></figure>

Coral-orbitolinid facies

<figure><img src="image_12.png" /></figure>

Peloidal-rudist facies

<figure><img src="image_13.png" /></figure>

Quartz-rich spongolithic facies

<figure><img src="image_14.png" /></figure>

Muddy basinal facies

<figure><img src="image_15.png" /></figure>

Glaucitic sand facies
<figure><img src="image_16.png" /></figure>

<figure><img src="image_17.png" /></figure>
A

A¹ p.p.

U³

D3

B

2 mm

0 2m

D4

Blue-grey A² marls

D3

U³p.p.

Yellowish marls - A¹

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C

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D

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D3

U3 p.p.

<figure><img src="image_25.png" /></figure>

Yellowish marls - A¹

A² pro parte

D4

<figure><img src="image_26.png" /></figure>

B

<figure><img src="image_27.png" /></figure>

A

<figure><img src="image_28.png" /></figure>
<figure><img src="image_29.png" /></figure>

A

D3

D4

A1

A2

B

D4

A1

D3

C

<figure><img src="image_30.png" /></figure>

<figure><img src="image_31.png" /></figure>

<figure><img src="image_32.png" /></figure>

D4

D3
Blue-grey marls - A2 *pro parte*

<figure><img src="image_33.png" /></figure>

<figure><img src="image_34.png" /></figure>
Lower APTIAN

Upper BARREMIAN

IUGS standard zonation

<table><thead><tr><th>ZONES</th><th>SUBZONES</th></tr></thead><tbody><tr><td rowspan="3">Dufrenoyia furcata</td><td>Dufrenoyia dufrenoyi</td></tr><tr><td>Dufrenoyia furcata</td></tr><tr><td>Deshayesites deshayesi</td></tr><tr><td rowspan="2">Deshayesites forbesi</td><td>Deshayesites grandis</td></tr><tr><td>Roloboceras hambrovi</td></tr><tr><td>Deshayesites luppovi</td><td>Deshayesites forbesi</td></tr><tr><td>Deshayesites oglanlensis</td><td>Deshayesites oglanlensis</td></tr><tr><td rowspan="2">Martelites sarasini</td><td>Pseudocrioceras waagenoides</td></tr><tr><td>Martelites sarasini</td></tr><tr><td rowspan="3">Imerites giraudi</td><td>Heteroceras emerici</td></tr><tr><td>Imerites giraudi</td></tr><tr><td>Hemihoplites feraudianus</td></tr><tr><td rowspan="3">Gerhardtia sartousiana</td><td>Gerhardtia provincialis</td></tr><tr><td>Gerhardtia sartousiana</td></tr><tr><td>Barrancyloceras barremense</td></tr><tr><td>Toxancyloceras vandenheckii</td><td>Toxancyloceras vandenheckii</td></tr></tbody></table>

Ropolo et al. (2006, 2008a-b) zonation

<table><thead><tr><th>SUBZONES</th><th>ZONES</th></tr></thead><tbody><tr><td>Cheloniceras mevendorffi</td><td>Dufrenoyia furcata</td></tr><tr><td>Paradeshayesites grandis</td><td>Deshayesites deshayesi</td></tr><tr><td>Roloboceras hambrovi</td><td>Paradeshayesites weissi</td></tr><tr><td>Pseudocrioceras waagenoides</td><td>Paradeshayesites oglanlensis</td></tr><tr><td>Martelites sarasini</td><td></td></tr></tbody></table>

U. BARR. pro pure

L. BED.

Upper BED.
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e

f

i

j

o

p

q

r
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a

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b

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c

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d

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e

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f

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g

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h

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i

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j

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k

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l

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m

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n

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o

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p

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q

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r

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s

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t

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u

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v

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w

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x

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y

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z
<figure><img src="image_92.png" /></figure>

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<figure><img src="image_94.png" /></figure>

<figure><img src="image_95.png" /></figure>

$\delta^{13}\text{C}_{\text{carb}}$

<figure><img src="image_96.png" /></figure>

$\delta^{18}\text{O}_{\text{carb}}$

<figure><img src="image_97.png" /></figure>

P [ppm]

<figure><img src="image_98.png" /></figure>

<figure><img src="image_99.png" /></figure>

<figure><img src="image_100.png" /></figure>
D. forbesi

Casey et al. (1998)
zonal scheme

D. annelidus

D. callidiscus

D. kiliani

D. fittoni

<figure><img src="image_101.png" /></figure>

?

IUGS standard
zonal scheme

R. hambrovi

D. forbesi

R. hambrovi

This work

D. forbesi
south-western Bas-Vivarais

(Serviers-et-Labaume - Saint-Nicolas)

north-eastern Bas-Vivarais

(Saint Montan - Bourg-Saint-Andéol)

North Provence

(Fontaine-de-Vaucluse - Murs-Joucas)

South Provence

(Cassis - Roquefort-la-Bédoule)

<figure><img src="image_102.png" /></figure>