Membre de La May

Zur Übersicht

Darstellung, Status

Index
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CMYK-Farbe
cf. Formation de Courgenay
RGB-Farbe
R: 155 G: 195 B: 215
Rang
lithostratigraphisches Member
Gebrauch
Element ist in Gebrauch
Status
gültiger formeller Begriff
SKS-Notiz
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SKS-Datum
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Kommentar
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Nomenklatur

Deutsch
La-May-Member
Französisch
Membre de La May
Italienisch
Membro di La May
Englisch
La May Member
Herkunft des Namens

Petite vallée de La May, 2.5 km NE de St-Ursanne (JU)

Historische Varianten
Humeralis-Kalke auct., La May-Schichten (Gygi 1995 S.12), La May Member (Gygi 2000c)
Nomenklatorischer Kommentar
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Synonyme

Synonyme
Nicht-Synonyme
Verwechslungsgefahr

Beschreibung

Beschreibung
Calcaire micritique, bien lité, pas d’ammonites mais des bivalves (Pholadomya). yellow, "spary-oolithic" limestone
Geomorphologischer Ausdruck
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Mächtigkeit
20-30 m (Aufranc et al. 2016), 31 m à Courgenay (Gygi 2000c)

Komponenten

Lithologien
  • Kalkstein
Mineralien
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Fossilien
  • Brachiopoden

Hierarchie und Abfolge

Übergeordnete Einheit
Formation de Courgenay
Untergeordnete Einheiten
Hangendes
Liegendes
Membre de Bure
Laterales Äquivalent
Obergrenze
-
Untergrenze
Marnes du Mb. de Bure (masqué)
Stratigraphische Diskussion
-

Alter

Alter Top
Frühes Kimméridgien
Bermerkungen zu Top
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Alter Basis
spätes Oxfordien
Bermerkungen zu Basis
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Datierungsmethode
Coulée de débris

Geografie

Paläogeografie
Nord de la suisse
Typusregion
Typlokalität
  • La May (JU)
    Merkmale des Ortes
    • typical facies
    Koordinaten
    • (2580750 / 1247500)
    Notizen
    • Petite vallée 2.5 km NE de St-Ursanne (Gygi 2000b/c Profil RG337)
Typusprofil
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Referenzprofile
  • La Coperie (JU)
    Merkmale des Ortes
    • upper boundary
    • lower boundary
    • typical facies
    Zugänglichkeit des Ortes
    • drill core
    Koordinaten
    • (2580900 / 1246230)
    Notizen
    • forage d'exploration de la Transjurane (Gygi 2000b Pl.20 Profil RG443)
Point of interest
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Paläogeografie und Tektonik

Paläogeografie
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Herkunftstyp
  • sedimentär
Bildungsbedingungen
-
Sequenz
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Tektonische Einheit (bzw. Überbegriff)
Jura
  • Süddeutschland
  • Schwarzwald
  • Jura méridional
  • Vogesen
Metamorphose
unmetamorph
Metamorphosefazies
-
Bemerkung zur Metamorphose
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Referenzen

Neubearbeitung
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: The La May Member below is a well-bedded micritic limestone with a thickness of 31 m in the section RG 350 at Chemin Paulin.

p.134: La May Member (Gygi 1995) ; Previously "Humeralis-Kalke". Member of the Courgenay Formation ; Synonymy: Gygi (2000b, p. 61)

The La May Member was named by Gygi (1995. p. 12). The name refers to the small valley called La May 2.5 km northeast of St-Ursanne in Canton Jura. LK 1085 St-Ursanne. where part of the member crops out at coordinates ca. 580.750/247.500 in the unpublished section RG 337. Below is the marl of the Bure Member which is covered, and above is a good outcrop of the massive Porrentruy Member. The only complete section of the La May Member was provided by the exploration well for the Transjurane superhighway near La Coperie farm 2 km east of St-Ursanne. This is section RG 443 which is represented as plate 20 in Gygi (2000b). The limestone of the La May Member is mostly micritic, well-cemented and well-bedded. Rounded lithoclasts of micrite grow to a diameter of 10 mm and are not rare. Macrofossils are Cycloserpula socialis (Goldfuss) and the bivalve Pholadomya. The thickness of the member is about 30 m in the borehole near La Coperie that Gygi (2000b p. 61) proposed to be the type section for lack of a complete outcrop at the surface. No ammonites have been found in the La May Member to date. The clay mineral stratigraphy by Gygi & Persoz (1986. Pl. 1A) indicates that the age of the La May Member ranges from the Hauffianum Subchron ofthe Bimammatum Chron to the lower Planula Chron (Gygi. 1995. Fig. 2). The La May Member occurs only in Canton Jura. The boundaries of the member with the Laufen and Verena Members are transitional.

Wichtige Publikationen
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Material und Varia

Anwendungen
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