Formazione di Ternate

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Représentation et statut

Couleur CMYK
(0%,21%,90%,6%)
Couleur RGB
R: 240 G: 190 B: 25
Rang
Formation lithostratigraphique
Usage
Ce terme est en usage.
Status
valide

Nomenclature

Deutsch
Ternate-Formation
Français
Formation de Ternate
Italiano
Formazione di Ternate
English
Ternate Formation
Origine du nom

Ternate (Italia)

Variantes historiques

Obereozän von Travedona-Ternate, ... (Herb 1976, Bernoulli 1980, Bernoulli et al. 1988, Mancin et al. 2001), Ternate Formation (Bernoulli et al. 1988), Formazione di Ternate (Bernoulli et al. 2018)

Description

Description

Geröllpetrographie: spiculitische Kalke und Mergelkalke (Lias), Scaglia Lombarda, Tertiäre hemipelagische Mergel, sowie Trias-Dolomiten, Radiolariten, Maiolica und Oberkreide-Flysch.

Épaisseur
Ca. 150 m.

Composants

Fossiles
  • nummulites
  • algues
  • mollusques
  • foraminifères
  • bryozoaires

Hiérarchie et succession

Limite supérieure

Gerölle der Ternate-Fm. in den oligozänen marinen Konglomeraten zwichen Como und dem Lago Maggiore (Gunzenhauser).

Limite inférieure

Aufarbeitung der liegenden Einheiten (inkl. des frühen und mittleren Eozäns).

Âge

Âge au sommet
  • Priabonien
Âge à la base
  • Priabonien
Méthode de datation

Planktonische und benthonische Foraminiferen des späten Eozäns.

Géographie

Extension géographique
Ternate - Travedona.
Point of interest

Paléogéographie et tectonique

Termes génériques
Type de protolithe
  • sédimentaire

Références

Révision
Bernoulli Daniel, Herb René, Grünig Angela (1988) : The Ternate Formation, a Late Eocene bioclastic submarine fan of the Lombardian Basin (Southern Alps). AAPG Mediterranean Basins Conference (Nice)

The Ternate Formation consists of some 150 m of redeposited bioclastic limestones, channelized rubble beds, and pebbly mudstones and subordinate hemipelagic marls with a late Eocene fauna of planktonic Foraminifera (Globorotalia cerroazulensis cerroazulensis Zone). Parallel-bedded massive or graded bioclastic limestones are overlain by channelized deposits. Large channels are up to 12 m deep; some contain pebbly mudstones with large slabs and boulders of older marls and limestones in a matrix of middle Eocene marls. More typically, the channels are filled by pebbly calcirudites grading into calcarenites and laterally wedging out over very short distances. Interchannel deposits are thin-bedded, graded calcarenites and thin green marls. The bioclastic limestones contain mainly coralline algae, larger Foraminifera (nummulitids, Discocyclina), bryozoans, echinoderms, and other shallow-water biota. All lithic fragments are of local, south-Alpine origin. By far the most abundant are spiculitic limestones and marls of Liassic age and Upper Cretaceous to middle Eocene limestones and marls. Most of the redeposited calcareous sand and gravel was deposited in ephemeral channels which cut across each other in a very complex way and were briefly active. This depositional system matches the suprafan environment of a prograding submarine fan of low transport efficiency. The facies of the conglomerates, the local source of the lithic fragments, and comparison with other lower Tertiary bioclastic deep-water deposits suggest short transport and deposition in one (or a series) of local bioclastic submarine fans. The benthic Foraminifera associated with the hemipelagic marls indicate deposition in the upper bathyal zone (600-1,000 m).

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