The Staffelegg Formation (

German German(s) may refer to: * Germany, the country of the Germans and German things **Germania (Roman era) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizenship in Germany, see also Ge ...

: Staffelegg-Formation,

French French may refer to: * Something of, from, or related to France ** French language, which originated in France ** French people, a nation and ethnic group ** French cuisine, cooking traditions and practices Arts and media * The French (band), ...

: Formation de la Staffelegg,

Italian Italian(s) may refer to: * Anything of, from, or related to the people of Italy over the centuries ** Italians, a Romance ethnic group related to or simply a citizen of the Italian Republic or Italian Kingdom ** Italian language, a Romance languag ...

: Formazione della Staffelegg) is a

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondary ...

Early Jurassic The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic� ...

age ( late Hettangian to early Toarcian stages) in the

Canton of Aargau Aargau ( ; ), more formally the Canton of Aargau (; ; ; ), is one of the 26 cantons forming the Swiss Confederation. It is composed of eleven districts and its capital is Aarau. Aargau is one of the most northerly cantons of Switzerland, by th ...

of northern

Switzerland Switzerland, officially the Swiss Confederation, is a landlocked country located in west-central Europe. It is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland ...

. The

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility. Although its permeabil ...

marl Marl is an earthy material rich in carbonate minerals, Clay minerals, clays, and silt. When Lithification, hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae. M ...

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

s and intermittent

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

s of the formation were deposited on the Northern Tethyan Carbonate Platform (NTCP). The Staffelegg Formation has provided fossils of the

ichthyosaur Ichthyosauria is an order of large extinct marine reptiles sometimes referred to as "ichthyosaurs", although the term is also used for wider clades in which the order resides. Ichthyosaurians thrived during much of the Mesozoic era; based on fo ...

'' Eurhinosaurus longirostris'' and the

ammonite Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

'' Catacoeloceras raquinianum''.

Description

The formation is found in the northern canton of Aargau of Switzerland and has a thickness of , and in the Mont Terri area approximately . The Staffelegg Formation is named after the Staffelegg Pass, overlies the Keuper Group and is overlain by the Opalinus Clay. The formation comprises

s and

s. Additionally,

s and subordinately also

s may occur especially in the

Sinemurian In the geologic timescale, the Sinemurian is an age (geology), age and stage (stratigraphy), stage in the Early Jurassic, Early or Lower Jurassic epoch (geology), Epoch or series (stratigraphy), Series. It spans the time between 199.5 ±0.3 annu ...

part. In the Folded Jura, these sediments may make up the major portion of the Staffelegg Formation. Facies changes may occur within short distances in the Folded Jura. The Staffelegg Formation displays a small thickness compared to the occurrences of the Early Jurassic of southeastern France and southwestern Germany. A gradual decrease in thickness can be detected which continues from southwestern Germany into northern Switzerland. Formerly, the formation was considered part of the

Posidonia Shale The Posidonia Shale (, also called Schistes Bitumineux in Luxembourg) geologically known as the Sachrang Formation, is an Early Jurassic (Early to Late Toarcian) geological formation in Germany, northern Switzerland, northwestern Austria, souther ...

, until it was defined as a separate formation by Reisdorf et al. in 2011.Reisdorf et al., 2011a The formation was deposited on the Northern Tethyan Carbonate Platform. The Staffelegg Formation dates from the late Hettangian to early Toarcian.Staffelegg Formation
at Strati.ch

Subdivision

The Staffelegg Formation is subdivided into: * Gross Wolf Member * Rietheim Member * Rickenbach Member * Breitenmatt Member * Grünschholz Member * Frick Member * Fasiswald Member * Membre du Mont Terri * Weissenstein Member * Beggingen Member * Schambelen Member

Fossil content

Among others, the following fossils have been reported from the formation:Staffelegg Formation
at

Fossilworks Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cr ...

.org

Reptiles

;Ichthyosaurs * '' Eurhinosaurus longirostris''Reisdorf et al., 2011b * '' Hauffiopteryx typicus'' * ''Protoichthyosaurus'' cf. ''applebyi'' * ''

Stenopterygius ''Stenopterygius'' is an extinct genus of thunnosaur ichthyosaur known from Europe (England, France, Germany, Luxembourg and Switzerland). History ''Stenopterygius'' was originally named by Quenstedt in 1856 as a species of ''Ichthyosaurus'', '' ...

'' sp. * ?''

Temnodontosaurus ''Temnodontosaurus'' (meaning "cutting-tooth lizard") is an extinct genus of large ichthyosaurs that lived during the Lower Jurassic in what is now Europe and possibly Chile. The first known fossil is a specimen consisting of a complete skull a ...

'' sp.

Invertebrates

;Ammonites * '' Catacoeloceras raquinianum''

References

Bibliography

* *