A key section at L’Estellon, Drôme, France (a presentation given by Bruno R.C. Granier and coauthors on the occasion of STRATI2013). As for previous publications (Conrad et al., 2012; Charollais et al., 2013), we question the relevance of the conclusions and hypotheses of any published work based on the biased stratigraphic distribution ranges for the orbitolinids, i.e., any work based on Arnaud-Vanneau's (Arnaud-Vanneau et al., 2005, and earlier versions). There are 3 related publications: http://paleopolis.rediris.es/cg/CG2013_A03/index.html + http://paleopolis.rediris.es/cg/CG2013_A04/index.html + http://paleopolis.rediris.es/cg/CG2017_B01/CG2017_B01.pdf

1. Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France
Bruno GRANIER
Robert BUSNARDO
Bernard CLAVEL
Michel MOULLADE
Jean CHAROLLAIS
Guy TRONCHETTI
Pierre DESJACQUES
L’Estellon section is
located in the Diois
(Drôme department, SE
France), near the locality
of Nyons, a few kilometres
north to the Chaudebonne
section (Moullade, 1966)
and south to the Crupies
section (Ferry, 1976).

2. Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France
As in both aforementioned
sections the succession,
which consists of basinal
marls and associated
vermicular limestones,
includes a number of strata
made of conglomerates
(debris-flows) and
bioclastic allodapic
calcarenites (turbidites)
[one of them been locally
known as “barre à
orbitolines”] (from Granier
et al., in press).
Phyllopachyceras

3. Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France
As in both aforementioned
sections the succession,
which consists of basinal
marls and associated
vermicular limestones,
includes a number of strata
made of conglomerates
(debris-flows) and
bioclastic allodapic
calcarenites (turbidites)
[one of them been locally
known as “barre à
orbitolines”] (from Granier
et al., in press).
Zoophycos

4. A rich ammonite fauna
was collected while
measuring the section;
hereafter we listed some
significative findings,
which begin with Late
Hauterivian forms
(Crioceratites sp.,
Pseudothurmannia sp., P.
sarasini), followed by
Early (Emericiceras
emerici, Taveraidiscus sp.,
Taveraidiscus hugii,
Barremites sp.) and Late
(Heinzia sayni,
Toxancyloceras
vandenheckei, Gerhardtia
sartousiana, Hemihoplites
cf. feraudianus,
Acantholytoceras sp.,
Heteroceras sp.)
Barremian representatives.
Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France

5. A rich ammonite fauna
was collected while
measuring the section;
hereafter we listed some
significative findings,
which begin with Late
Hauterivian forms
(Crioceratites sp.,
Pseudothurmannia sp., P.
sarasini), followed by
Early (Emericiceras
emerici, Taveraidiscus sp.,
Taveraidiscus hugii,
Barremites sp.) and Late
(Heinzia sayni,
Toxancyloceras
vandenheckei, Gerhardtia
sartousiana, Hemihoplites
cf. feraudianus,
Acantholytoceras sp.,
Heteroceras sp.)
Barremian representatives.
Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France

6. Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France
Level 42 (Nicklesi Zone)
•Taveraidiscus hugii
(Ooster, 1860)
•Emericiceras emerici
(Léveillé, 1837)
(from Busnardo et al., in
press).
Note: Scarce occurrences
of planktonic foraminifers
and deep water benthic
foraminifers are reported
from the washed residues
of the marls and
contributed to date some
intervals.

7. Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France
The coarse-grained
floatstone and grainstone
facies bear a number of
foraminifers and
calcareous algae laterally
transported (“freshly
reworked”) from the
carbonate shelves
surrounding the Vocontian
Trough (from the west,
i.e., from the neighbouring
Vivarais, Ardèche
department). Their co-
occurrence with basinal
fossils allows us to
calibrate their FAD and
LAD directly on the
ammonite biozones.

8. Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France

9. Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France

10. Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France

11. Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France
The highest discrepancies
appear with Arnaud-
Vanneau‘s (2005).

12. Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France
On the contrary, the best
match was obtained with
Clavel‘s (2007, 2010).

13. Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France
Our first record of the
well-known Palorbitolina
lenticularis dates back
from the Pulchella Zone of
the Lower Barremian
strata, instead of from the
top of the Sartousiana
Zone of the Upper
Barremian (from Granier
et al., in press).
0.5mm

14. Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France
Another example is given
by four representatives
(kiliani, buccifer,
briacensis, cuvillieri) of
the genus Orbitolinopsis,
which have been said to be
Bedoulian (= “Early
Aptian”) in age, whereas
we found these taxa occur
in Lower Barremian strata
(from Granier et al., in
press).
0.5mm

15. Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France
The highest discrepancies
appear with Arnaud-
Vanneau‘s (2005). The best
match was obtained with
Clavel‘s (2007, 2010).

16. Refurbishing the Urgonian biostratigraphy:
A key section at L’Estellon, Drôme, France
As for previous publications (Conrad et al., 2012; Charollais et al.,
2013), we question the relevance of the conclusions and
hypotheses of any published work based on the biased stratigraphic
distribution ranges for the orbitolinids, i.e., any work based on
Arnaud-Vanneau's (Arnaud-Vanneau et al., 2005, and earlier
versions).