Holzflue-Member

Représentation et statut

Couleur CMYK

siehe Balsthal-Formation

Couleur RGB

R: 170 G: 195 B: 215

Rang

Membre lithostratigraphique (Sous-formation)

Usage

Ce terme est en usage.

Status

terme formel valide

Nomenclature

Deutsch

Holzflue-Member

Français

Membre de la Holzflue

Italiano

Membro della Holzflue

English

Holzflue Member

Origine du nom

Felsgrat Holzflue, nördlich Balsthal (SO)

Variantes historiques

«Höhlenkalk» auct. (Lang 1863), Holzflue-Schichten (Gygi 1969), Holzflue Member (Gygi 2000b, Gygi 2000c)

Description

Description

Das Holzflue-Member besteht aus einer Wechsellagerung von weissen, oolithischen Grainstones und Mikriten.

Épaisseur

70 m an der Typlokalität

Hiérarchie et succession

Unité hiérarchiquement supérieure

• Balsthal-Formation

Unités hiérarchiquement subordonnées

• Balmberg-Oolith

Unités sus-jacentes

• Formation de Reuchenette

Unités sous-jacentes

• Steinibach-Member

Âge

Âge au sommet

• Kimméridgien précoce

Note sur le sommet

Planula-Zone

Âge à la base

• Oxfordien tardif

Note sur la base

Bimammatum-Z.

Méthode de datation

Mineralostratigraphie: Ton (Gygi 2000c S.133)

Géographie

Extension géographique

Kanton Solothurn

Région-type

Solothurner Jura (SO)

Localité-type

• Holzflue (SO)
  Particularités du site
  • typische Fazies
  Accessibilité du site
  • Grat
  Coordonnées
  • (2619840 / 1241390)

Typusprofil

• Steinbachtobel (SO)
  Particularités du site
  • Obergrenze
  • Untergrenze
  • typische Fazies
  Accessibilité du site
  • Bachprofil
  Coordonnées
  • (2619370 / 1241350)
  Note
  • Steinbachtobel (Gygi 1969 Pl.18 Profil RG9, Gygi 2000b Pl.44 Profil RG438)

Paléogéographie et tectonique

• Malm du Jura

Paléogéographie

plateforme carbonatée nord-téthysienne :
Plateforme de Bourgogne, ... = Northern Tethyan Carbonate Platform (NTCP)

Termes génériques

• Jura :
  Juragebirge

Type de protolithe

• sédimentaire

Métamorphisme

non métamorphique

Références

Définition

Gygi R. A. (1969) : Geologische Beschreibung des Aargauer-Jura und der nördlichen Gebiete des Kantons Zürich.

"Zwischen der Hauptmumienbank unten und der Kimmeridge-Stufe oben liegt eine Schicht, die Juillerat (1907) «oolithe blanche séquanienne» genannt hat. Da das Gestein nicht überall weiss und oolithisch ist und weil das Séquanien als Stufenname nicht mehr gebraucht werden kann, wird vorgeschlagen, die Schichten 9/15-19 Holzflue-Schichten zu nennen und Profil 9 zum Typusprofil zu erklären." S.86

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.133: Holzflue Member (Gygi 1969) ; Member of the Balsthal Formation ; Synonymy: Gygi (2000b. p. 63) The name Holzflue Member (Holzflue-Schichten) was proposed by Gygi (1969. p. 86) and refers to Mt. Holzflue north of Balsthal. Canton Solothurn. LK 1107 Balsthal. The type section is RG 9 in Gygi (1969. PI. 18) or the revised section RG 438 on plate 44 in Gygi (2(XX)b). respectively, that was measured at the same locality in the Steinebach gorge. Holzflue Member is a necessary name for the distal part of the Balsthal Formation. In the proximal part, the Laufen Member (Gygi 1995. p. 13) below and the Verena Member above can be distinguished above the Steinebach and Hauptmumienbank Members. At Balsthal and further to the east towards Olten this is impossible as is indicated in figure 1.
The Holzflue Member is 70 m thick at the type locality. Most of it is oolite, but there is a micritic intercalation in the type section: the middle part of bed 44 of section RG 438. The oolite in the upper part of the Holzflue Member is somewhat friable and weathers back as a hollow at Mt. Holzflue and north of the road tunnel in Steinebach gorge. The rock becomes a pure white, porous and very friable oolitic grainstone in the upper part of the quarry of Mösliloch at the western slope of Vorberg west of the village of Egerkingen. Canton Solothurn. LK 1108 Murgenthal. This is the upper part of bed no. 57 in the unpublished section RG 448. In one of the former quarries at the locality called Loch at Wangen. Canton Solothurn (west of Olten. LK 1088 Hauenstein), the rock of the Holzflue Member is a porous, white micrite (Gygi 1969. Pl.19). This is the type locality of the Wangen Member as conceived by Moesch (1867. p. 165).
The age of the Holzflue Member could only be established with clay minerals. The member belongs to the later part of the Bimammatum Chron and to the Planula Chron. The upper Holzflue Member at Mt. Holzflue cannot be distinguished from the Verena Member at St. Verena chapel, the type locality of the Verena Member (see below). The eastern boundary of the Holzflue Member is marked by the Olten Member, a limestone with hermatypic corals. There is a transition between the upper Holzflue Member and the upper Letzi Member at Olten (Gygi 1969. Pl. 19). The colour of the Holzflue Member is lighter than that of the oolitic Steinebach Member below that has a brownish tinge. But near Balsthal the uppermost Steinebach Member is an almost white friable oolite that weathers back. This was already noted by Delhaes & Gerth (1912. p. 18).