GSSP for Hauterivian Stage
Definition:
The base of the Hauterivian Stage is defined at the base of Bed 189 of the La Charce Section, Drôme, France. This level coincides with the first appearance of the ammonite genus Acanthodiscus which marks the base of the Acanthodiscus radiatus ammonite zone.
Location:The GSSP of the Hauterivian Stage is located 550m west of the village of La Charce, Drôme, France at a latitude of 44°28’10.0"N and a longitude of 5°26’37.4"E. It is located on the Luc- en-Diois sheet of the "Carte géologique de la France" at the 1/50000 scale (Flandrin et al., 1970) and on the topographic sheet, scale 1/25000, Luc-en Diois, no IGN 3615. |
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Sedimentology:The GSSP section is 40m thick and lies in the "Calcaires marneux à ? Hoplites Formation sensu Paquier (1900).The lower 8m of the section (beds 182 to 188) consist of irregularly spaced, medium grey argillaceous limestone layers ranging from 10 to 50 cm in thickness. They alternate with greyish marly layers, 0.50 to 1.0 m thick, rarely up to 2.00 m. The following 24 m (beds 189 to 214; Acanthodiscus radiatus ?Zone), are characterized by 0.20 to 0.50 m thick, light grey limestone layers alternating with darker grey marly layers almost of equivalent thickness. The limestone layers may exceed 1.0 m or more becoming thereby very prominent. Bed 189 contains the GSSP level. The uppermost part of the Acanthodiscus radiatus Zone is marked by a minor slump (bed 215) around 3.50 m in thickness. The transition to the overlying 4.50 m thick unit (beds 216 to 221; Crioceratites loryi ammonite Zone) is marked by a monotonous sequence of limestones (0.4 to 0.6 m thick) and marly layers (0.2 - 0.3 m thick). |
Primary Markers:
The base of the Hauterivian Stage corresponds to the first occurrence of the ammonite genus Acanthodiscus.Secondary Markers:
Magnetostragraphy:The top of Chron M10Nn.3n coincides with the base of the Hauterivian and may serve as an interregional correlation event.
Ammonites and nannofossils:
The following ammonite and calcareous nannofossil events are useful for interregional correlations and as secondary markers:
Bed 217 |
FAD of Diloma galiciense (calcareous nannofossil) |
Bed 214 |
FAD of Saynella mucronata (ammonite) |
Bed 213 |
LAD of Eiffelithus windii (calcareous nannofossil) |
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LAD of Tribrachiatus sp. (calcareous nannofossil) |
Bed 197 |
FAD of Leopoldia leopoldina (ammonite) |
Bed 194 |
FAD of Spitidiscaus (gr. lorioli- meneghinii) (ammonite) |
Bed 193 |
FAD of Breistrofferella castellanensis (ammonite) |
Bed 190 |
FAD of Breistrofferella varapensis (ammonite) |
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FAD of Staurolithites mitcheneri (calcareous nannofossil) |
Bed 189 |
FAD of Acanthodiscus rebouli (ammonite), Base of Hauterivian |
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FAD of Teschenites flucticulus (ammonite) |
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FAD of Teschenites pachydicranus (ammonite) |
Bed 186 |
FAD of Teschenites callidiscus (ammonite) |
Correlation Events:
Ammonite FAD of genus AcanthodiscusNotes on Derivation of Age:
Pacific spreading model for magnetic anomaly ages (variable rate), using placement at base M11nReferences:
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