Crenularis-Member

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Représentation et statut

Index
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Couleur CMYK
cf. Villigen-Formation
Couleur RGB
R: 185 G: 195 B: 215
Rang
Membre lithostratigraphique
Usage
Ce terme est en usage.
Statut
terme formel valide
SCS note
-
SCS date
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Commentaire
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Nomenclature

Allemand
Crenularis-Member
Français
Membre à Crenularis
Italien
Membro a Crenularis
Anglais
Crenularis Member
Origine du nom

Namengebendes Fossil: Echinoidenart Hemicidaris crenularis (Lamarck) Agassiz.

Variantes historiques
Crenularisschichten (Moesch 1863 S.157, Tobler 1905 Tab.4a, Disler 1941), Crenularis-Schichten (Hantke 1967), Crenularis Member (Gygi 2000c), Couches à Hemicidaris crenularis
Remarques nomenclatoriales
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Synonymie

Synonymes
Non synonymes
Risques de confusion

Description

Description
Das Crenularis-Member besteht aus Kalksteinen. In den glaukonitischen Lagen kommen lokal Schwammnadeln vor.
Expression géomorphologique
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Epaisseur
Ca. 3-4,5 m ; 17 m bei Mellikon in atypischer Fazies (Schwamm-Bioherm ; Gygi 1969)

Composants

Lithologies principales
  • calcaire
Minéraux particuliers
  • glauconite
Fossiles principaux
  • éponges
  • échinoïdes
  • bivalves

Hiérarchie et succession

Unité hiérarchiquement supérieure
Villigen-Formation
Unités hiérarchiquement subordonnées
Unités sus-jacentes
Unités sous-jacentes
Geissberg-Member
Équivalents latéraux
Limite supérieure
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Limite inférieure
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Discussion stratigraphique
Nach Gygi (1969) ist die Mächtigkeit des Crenularis-Members 17 m im Steinbruch von Mellikon, aufgrund von Schwamm-Riffen. Diese atypische Fazies markiert den Übergang zum Hornbuck-Member weiter östlich.

Âge

Âge au sommet
Oxfordien tardif
Note sur le sommet
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Âge à la base
Oxfordien tardif
Note sur la base
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Méthode de datation
Biostratigraphie: Ammoniten der Berrense- bis Bimammatum-Zone (Gygi 2000b/c). Bimammatum-Subzone (Enay et al. 1988).

Géographie

Extension géographique
Von Oftringen im Westen bis Lägern im Osten und im Aargauer Tafel-Jura.
Région-type
Localité-type
  • Villiger Geissberg (AG)
    Particularités du site
    • typical facies
    Accessibilité du site
    • road cut
    Coordonnées
    • (2657785 / 1264055)
    Note
    • Kote 510 m (Gygi 1969 S.69 Profil RG62), Kompositprofil
Coupe-type
  • Villiger Geissberg (AG)
    Particularités du site
    • typical facies
    Accessibilité du site
    • road cut
    Coordonnées
    • (2657785 / 1264055)
    Note
    • Kote 510 m (Gygi 1969 S.69 Profil RG62), Kompositprofil
Coupes de référence
  • Gabenchopf (AG)
    Particularités du site
    • typical facies
    Accessibilité du site
    • quarry
    Coordonnées
    • (2656965 / 1265050)
    Note
    • 2 km NW Villigen (Gygi 2000c)
Point of interest
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Paléogéographie et tectonique

Paléogéographie
bassin argovien,
Type de protolithe
  • sédimentaire
Conditions de formation
"argovien" / "séquanien"
Séquence
-
Unité tectonique (resp. catégorie générique)
Jura
  • Sud de l'Allemagne
  • Forêt Noire
Métamorphisme
non métamorphique
Faciès métamorphique
-
Remarque sur le métamorphisme
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Références

Définition
Moesch Casimir (1863): Geologische Beschreibung des Aargauer-Jura und der nördlichen Gebiete des Kantons Zürich. , Beitr. geol. Karte Schweiz 4

S.157
Révision
Gygi R. A. (2000): Annotated index of lithostratigraphic units currently used in the Upper Jurassic of northern Switzerland. , Eclogae geol. Helv. 93/1, 125-146

p.129: Crenularis Member (Moesch 1863) ; Member of the Villigen Formation Moesch (1863. p. 157) named the Crenularis Member (Crenularisschichten) that became well-known because ofthe geological maps by Mühlberg. The name is derived from the echinoid Hemicidaris crenularis (Lamarck) that rarely occurs in the member. Moesch (1863 and 1867) did not indicate a type locality. Gygi (1969. p. 69) declared his section RG 62 along the road from Villigen to Mt. Geissberg, Canton Aargau, to be the type locality of the member. The road there crosses the well-exposed Crenularis Member at the elevation of about 510 m at coordinates 657.890/264.040, LK 1070 Baden. This section is however unfavorable as a type section, because the outcrops along the road are discontinuous. The continuous section RG 62 was assembled from five partial sections that were measured on both sides of the short valley through which the road runs. The locations of the partial sections are indicated in Gygi (1969. p. 61-62). A good and complete outcrop of the typical Crenularis Member is at present accessible in the upper part of the large quarry west of Gabenchopf 2 km westnorthwest of Villigen (LK 1070 Baden). This quarry can serve as reference section.
The Crenularis Member is a biomicritic limestone with uneven bedding planes and a knobby weathering. According to Gygi (1969. Pl. 19). the mean thickness of the member is 3 m. It contains siliceous sponges and abundant bivalves, mainly of the genus Pholadomya. Ammonites are rather rare, but the mineral glauconite is always present. The member is dated biochronologically by the ammonite Epipeltoceras cf. bimammatum (Quenstedt) J 31726 in the Museum of Natural History Basel that was found by Moesch and figured by Gygi (2000b, Pl. 10. Fig. 5). The ammonite is from bed 31 in the unpublished section RG 36 of Fahr quarry at Auenstein. Canton Aargau, LK 1089 Aarau. It documents the early Bimammatum Subchron. The Crenularis Member can be followed from Oftringen, Canton Aargau in the west to east of Burghorn on Mt. Lägeren east of Baden. Canton Aargau (Gygi 1969, p. 70). In the tabular Jura of Canton Aargau it extends to Baldingen.
The thickness of the member greatly increases to 17 m near Mellikon. Canton Aargau (Gygi 1969. Pl. 17 and 19) because of the growth of sponge bioherms. This is an atypical local facies which is transitional to the Hornbuck Member in the Klettgau valley. In the proximal direction (to the west), the Crenularis Member can be traced into the lowermost Olten Member of Gygi (1969) that was also called Crenularis Member by Moesch (1867, p. 150).

Principales publications
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Matériel et divers

Utilisations
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