Membre de Sornetan

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Representation and status

Index
i4-5S
CMYK Color
cf. Formation de Bärschwil
RGB color
R: 170 G: 175 B: 120
Rank
lithostratigraphic Member
Validity
Unit is in Use
Status
valid formal name
SCS note
-
SCS date
-
Comment
Die Anzahl der Lagen mit Kalkkonkretionen nimmt nach oben allmählich zu. Die Grenze zum Liesberg-Member ist durch das Einsetzen von Korallen markiert. Ein komplettes Referenzprofil findet sich in der Tongrube Andil bei Liesberg. In der französischen Literatur bezieht sich das “Terrain à Chailles” auf das Argovien (Gygi 2003).

Nomenclature

German
Sornetan-Member
French
Membre de Sornetan
Italian
Membro di Sornetan
English
Sornetan Member
Origin of the Name

Sornetan (BE)

Historical Variants
Membre de Sornetan (Gygi 2000b, Aufranc et al. 2017)
Nomenclatorial Remarks
-

Synonyms

Synonyms
Non-synonyms
Possible confusion

Description

Description
Grauer, mergeliger Ton mit Lagen von Kalkkonkretionen, die nach oben häufiger werden, führt Ammoniten, Bivalven, Echiniden, Crinoiden.
Geomorphology
-
Thickness
46 m bei Liesberg, 37,5 m in Anwil.

Components

Lithological content
  • claystone : karbonatfrei
Mineral content
-
Fossil content
  • ammonites
  • crinoids
  • belemnites
  • echinoids
  • bivalves

Hierarchy and succession

Superordinate unit
Bärschwil-Formation
Subordinate units
Units at roof
Units at floor
Renggeri-Member
Lateral equivalents
Upper boundary
-
Lower boundary
Passage progressif.
Stratigraphic discussion
-

Age

Age at top
middle Oxfordian
Note about top
-
Age at base
middle Oxfordian
Note about base
-
Dating method
Ammonites: Zones à Cordatum et à Transversarium-Zone (Gygi & Marchand 1993, Gygi 1995)

Geography

Geographical extent
NW-Schweiz, siehe Karte Gygi 1990c, Fig. 2 - 4
Type area
Type locality
-
Type profile
Reference profiles
  • Hinter Chestel (BL)
    Site particularities
    • upper boundary
    • lower boundary
    • typical facies
    Site accessibility
    • quarry
    Coordinates
    • (2599550 / 1249500)
    Note
    • Gygi 2000b, Profil RG-306, Pl.21
Point of interest

Paleogeography and tectonic

Paleogeography
-
Kind of protolith
  • sedimentary
Conditions of formation
-
Sequence
Within this interval, the content in fossil debris slightly increases up to the so-called “fossil-rich bed”, which is located roughly in the middle of the Terrain à Chailles. [...] In the mud-dominated Terrain à Chailles, maximum quartz content as well as abundant serpulids appear to characterize SB Ox3. Levels rich in ferroan calcite cement and glauconite indicating slow sedimentation are interpreted as flooding or maximum-flooding surfaces. (Wetzel & Strasser 2001)
Tectonic Unit (resp. main category)
Jura
  • Southern Germany
  • Black Forest
Metamorphism
non metamorphic
Metamorphic facies
-
Note on metamorphism
-

References

Definition
Gygi R. A. (2000): Integrated stratigraphy of the Oxfordian and Kimmeridgian (Late Jurassic) in northern Switzerland and adjacent southern Germany. , Denkschriften der Schweizerischen Akademie der Naturwissenschaften 104, 152 S.

p.53
Important publications
-

Material and varia

Applications
-