Membre de Delémont

Rappresentazione e statuto

Colore CMYK

N/A

Colore RGB

R: 125 G: 125 B: 125

Rango

Membro litostratigrafico (Sotto-formazione)

Uso

Unità in uso.

Status

termine scorretto (informale)

SCS nota

Wegen der möglichen Verwechslung mit dem "Delémontien" wurde das Delémont-Member (Gygi 2000b) in Chestel-Member umbenannt.

Discussione del statuto

Nomenclatura

Deutsch

Delémont-Member

Français

Membre de Delémont

Italiano

Membro di Delémont

English

Delémont Member

Origine del nome

Chapelle de Vorbourg, NW Delémont (JU)

Varianti storiche

Couches de Delémont, Delémont-Schichten, Delémont Member (Gygi 2000b, Gygi 2000c), Membre de Delémont (Comment & Ayer)

Nota sul nome

Name des Delémont-Members leitet sich ab vom Profil RG 366 (Schichten 1 bis 9), Chapelle du Vorbourg, nahe Delémont (Gygi 2000a, 56).

Descrizione

Potenza

24 m à Chestel ; 40 m (Comment & Ayer)

Gerarchia e successione

Unità di rango superiore

• Formation de St-Ursanne

Unità sovrastante

• Membre de Buix

Unità sottostante

• Liesberg-Member

Limite superiore

Membre de Buix

Limite inferiore

Membre de Liesberg

Osservazioni sulla stratigrafia

Das Delémont-Member verzahnt sich lateral mit dem Grellingen-Member (Gygi 2000a/b).

Età

Geomorfologia

• Oxfordiano medio

Osservazioni sul tetto

Transversarium-Zone, Antecedens-Subzone

Età alla base

• Oxfordiano medio

Osservazioni sulla base

Transversarium-Z., Antecedens-Sz.

Metodo di datazione

Ammonitenbiostratigraphie (indirekt): Funde aus dem Hangenden (Buix-Mb.) und Liegenden (Sornetan-Mb.), siehe Gygi (2000b, 130), Mineralostratigraphie.

Geografia

Estensione geografica

4 bis 8 km breiter Gürtel, der sich von Ocourt am Doubs nach St-Ursanne (JU), Delémont und Liesberg, Dittingen und Blauen/BL entlangzieht.

Località-tipo

• Chapelle de Vorbourg (JU)
  Caratteristiche del sito
  • Obergrenze
  • typische Fazies
  Agibilità del sito
  • Strassenanschnitt / Bahnanschnitt
  Coordinate
  • (2593870 / 1247660)
  Nota
  • route NW de la chapelle de Vorbourg (Gygi 2000b p.55 Profil RG 366, Schichten 1-9, Gygi 2000c)

Sezione di riferimento

• Chestel (BL)
  Caratteristiche del sito
  • Obergrenze
  • Untergrenze
  • typische Fazies
  Agibilità del sito
  • Steinbruch, Tongrube
  Coordinate
  • (2599690 / 1249570)
  Nota
  • Gygi 2000b S.56 Profil RG306 Schichten 107-110

Paleogeografia e tettonica

Termini generici

• Jura :
  Juragebirge

Tipo di origine

• sedimentaria

Condizioni di formazione

"rauracien"

Metamorfismo

non metamorfo

Referenze

Definizione

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.

S.55

Revisione

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: Delémont Member (Gygi 2000b) ; Member of the St-Ursanne Formation ; Synonymy: Gygi (2000b. p. 55) The Delémont Member of the lower St-Ursanne Formation was renamed by Gygi (20(X)b. p. 55). The name refers to Delémont. the capital of Canton Jura (LK 1086 Delémont). where the member crops out along the road northwest of Vorbourg chapel in section RG 366 (see plate 23 in Gygi, 2000b, beds 1-9). Gygi (2000b, p. 56) selected as reference section of the member RG 306, beds 107-110. in the quarry of Chestel at Liesberg, Canton Baselland, at coordinates 599.690/249.570, LK 1086 Delémont. The Delémont Member forms a 4-8 km wide belt within the lower St-Ursanne Formation. This belt runs from Ocourt on the Doubs river to St-Ursanne. Canton Jura. Delémont, and Liesberg, Dittingen and Blauen in Canton Baselland. The member is made up mainly by carbonate oolite and is 24 m thick in the reference section. There are hermatypic corals and oncoids at the base. Northeast of St-Ursanne the oncoids become so concentrated that they form an oncolite. This local facies was called Caquerelle pisolite by Ziegler (1962. p. 18). This must be distinguished from the Couches de la Caquerelle of Rollier (1892. p. 282). a synonym of the Buix Member (see above). The Caquerelle oncolite was figured by Pümpin (1965 Fig. 6 and 7). At present the oncolite is well exposed in the unpublished section RG 338 at the locality Côte du Frêne near Asuel. Canton Jura. LK 1085 St-Ursanne. at coordinates 581.950/247.990 along a forest road 400 m southwest of Les Malettes. The Delémont Member grades to the northwest and to the southeast into biomicritic limestone with hermatypic corals and coral bioherms. the Grellingen Member. No ammonites were found in the Delémont Member. There are ammonites of the early Antecedens Subchron in the upper Sornetan Member below and ammonites from the boundary between the Antecedens and Luciaeformis Subchron in the Buix Member above (Gygi, 1995. Fig. 2). The age of the Delémont Member can therefore be assigned to the Antecedens Subchron.