GSSP proposal for the upper Aptian substage in the Apt Basin (Vaucluse, SE France): Synthesis of the stratigraphic data

作者：Moullade Michel; Tronchetti Guy; Balme Christine; Dutour Yves; Ropolo Pierre^*; Price Gregory; Martinez Mathieu; Granier Bruno

来源：Carnets de Geologie, 2017, 17(9): 161-189.

DOI：10.4267/2042/62954

• Aptian
• Bedoulian
• Gargasian
• biostratigraphy
• quantitative micropaleontology
• isotopic stratigraphy
• stratotype
• GSSP

The synthesis of the stratigraphic data collected over more than a decade in the stratotypic area has made it possible to establish a composite section of the "Aptian marls" from the Grandis ammonite Subzone to the base of the Melchioris Zone, i. e., from the Schackoina (Leupoldina) gr. cabri foraminiferal Zone to the Globigerinelloides algerianus Zone. This composite section includes the partial sections from Clavaillan, South and East Pichouraz, La Tuilisre, Les Gays and Gargas (Vaucluse, SE France). In particular, our revision has shown that the marly calcareous bed, which divides the marly series of Clavaillan and Pichouraz, compared with the Vocontian "Niveau blanc" and thought to be unique and isochronous, corresponds in fact to two stratigraphically distinct levels.
The present study confirms that the visible series of marls in the stratotypic area, not taking into account the "A1" supra-Urgonian formation of LEENHARDT (1883), includes only the uppermost terms of the Bedoulian and the lower terms (= Lower and Middle Gargasian) of the Aptian s. s. (i. e., sensu ORBIGNY, 1840).
Based on the methods of integrated stratigraphy, a comparison of the series of the Apt Basin with the contemporary terms of the Cassis-La Bedoule Basin has also made it possible to detect and quantify important variations in the rhythms of sedimentary accumulation between the two sectors. In the end, the Clavaillan section, located 8 km WSW from the Gargas section, is the only outcrop where the boundary between the Grandis Subzone and the Furcata Zone is visible in a context which supports a proposal that this exposure be a candidate for the GSSP of the Gargasian substage (or of the Aptian s. s. in the initial concept of the creator of the stage).

• 出版日期2017-10-20