Crenularis-Member

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Representation and status

Index
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CMYK Color
cf. Villigen-Formation
RGB color
R: 185 G: 195 B: 215
Rank
lithostratigraphic Member
Validity
Unit is in Use
Status
valid formal name
SCS note
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SCS date
-
Comment
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Nomenclature

German
Crenularis-Member
French
Membre à Crenularis
Italian
Membro a Crenularis
English
Crenularis Member
Origin of the Name

Namengebendes Fossil: Echinoidenart Hemicidaris crenularis (Lamarck) Agassiz.

Historical Variants
Crenularisschichten (Moesch 1863 S.157, Tobler 1905 Tab.4a, Disler 1941), Crenularis-Schichten (Hantke 1967), Crenularis Member (Gygi 2000c), Couches à Hemicidaris crenularis
Nomenclatorial Remarks
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Synonyms

Synonyms
Non-synonyms
Possible confusion

Description

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

Components

Lithological content
  • limestone
Mineral content
  • glauconite
Fossil content
  • sponges
  • echinoids
  • bivalves

Hierarchy and succession

Superordinate unit
Villigen-Formation
Subordinate units
Lateral equivalents
Upper boundary
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Lower boundary
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Stratigraphic discussion
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.

Age

Age at top
late Oxfordian
Note about top
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Age at base
late Oxfordian
Note about base
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Dating method
Biostratigraphie: Ammoniten der Berrense- bis Bimammatum-Zone (Gygi 2000b/c). Bimammatum-Subzone (Enay et al. 1988).

Geography

Geographical extent
Von Oftringen im Westen bis Lägern im Osten und im Aargauer Tafel-Jura.
Type area
Type locality
  • Villiger Geissberg (AG)
    Site particularities
    • typical facies
    Site accessibility
    • road cut
    Coordinates
    • (2657785 / 1264055)
    Note
    • Kote 510 m (Gygi 1969 S.69 Profil RG62), Kompositprofil
Type profile
  • Villiger Geissberg (AG)
    Site particularities
    • typical facies
    Site accessibility
    • road cut
    Coordinates
    • (2657785 / 1264055)
    Note
    • Kote 510 m (Gygi 1969 S.69 Profil RG62), Kompositprofil
Reference profiles
  • Gabenchopf (AG)
    Site particularities
    • typical facies
    Site accessibility
    • quarry
    Coordinates
    • (2656965 / 1265050)
    Note
    • 2 km NW Villigen (Gygi 2000c)
Point of interest
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Paleogeography and tectonic

Paleogeography
Argovian Basin,
Kind of protolith
  • sedimentary
Conditions of formation
"argovien" / "séquanien"
Sequence
-
Tectonic Unit (resp. main category)
Jura
  • Southern Germany
  • Black Forest
Metamorphism
non metamorphic
Metamorphic facies
-
Note on metamorphism
-

References

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

S.157
Revision
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).

Important publications
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Material and varia

Applications
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