strati.ch - Lexique lithostratigraphique de la Suisse

Représentation et statut

Variantes historiques: Aalénien du torrent de la Raverette avec Posidonomya Bronni = Aalénien de la Raverette = Aalénien avec Posidonomya Bronni et des belemnites = Aalénien de l'écaille d'Oudioux (Lugeon 1938), Schistes noirs à miches = Schistes argileux noirs à miches pyriteuses (Badoux & Gabus 1991 p.13), Schistes à miches member (Ringgenberg et al. 2001)

Fossiles

Unité hiérarchiquement supérieure

Unités sus-jacentes

Âge au sommet

Âge à la base

Localité-type

Point of interest

Termes génériques

Type de protolithe

Révision: Ringgenberg Yann, Tomassi Alexander, Stampfli Gérard M. (2001) : The Jurassic sequence of the Niesen nappe in the region of Le Sépey - La Forclaz (Swirtzerland): witness of the Piemont rifting in the Helvetic paleogeographic domain. Bull. Soc. vaud. Sci. nat. 87/4, 353-372

2.1.1. «Schistes à miches» member (Aalenian) It consists of black clays full of micas containing calcareous, cherty and pyritic concretions that gave sometimes ammonites and bélemnites. Homewood and Badoux (1978) have found a specimen oî Leioceras giving an Aalenian age to the formation. At the top of the series, one can find a 2 m chaotic level with a matrix similar to the rest of the «Schiste à Miches» and containing segmented beds of micaceous sandstones. It is interpreted as a mudflow or a slump. The transition to the Raverette member is unexposed, but prior to the slump, there is a calcareous and micaceous polygenic bed of sandstone with chondrites that resembles the Raverette member. Therefore, the transition seems to be progressive and there is no reason to put a tectonic contact between those two members.