The Allgäu Formation is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...

. It preserves

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

dating back to the

Hettangian The Hettangian is the earliest age and lowest stage of the Jurassic Period of the geologic timescale. It spans the time between 201.3 ± 0.2 Ma and 199.3 ± 0.3 Ma (million years ago). The Hettangian follows the Rhaetian (part of the Triassi ...

Sinemurian In the geologic timescale, the Sinemurian is an age and stage in the Early or Lower Jurassic Epoch or Series. It spans the time between 199.3 ± 2 Ma and 190.8 ± 1.5 Ma (million years ago). The Sinemurian is preceded by the Hettangian an ...

stages of the

Early Jurassic The Early Jurassic Epoch (in chronostratigraphy corresponding to the Lower Jurassic Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event, 201.3 Ma ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

, or Raricostatum to Obtusum in the regional stratigraphy. Initially and formally defined by Jacobshagen (1965).Jacobshagen, 1965 The Allgäu Formation is formerly known as spotted marls (Lias-Fleckenmergel) and spotted marly limestones (Fleckenkalk). The formation is represented by dark-grey bioturbated

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms wh ...

s and

marlstone Marl is an earthy material rich in carbonate minerals, clays, and silt. When hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae. Marl makes up the lower part o ...

interbeds. It represents basinal hemipelagic faciesGawlick et al., 2009 common in Alpine Tethys regions of

Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, ...

Carpathians The Carpathian Mountains or Carpathians () are a range of mountains forming an arc across Central Europe. Roughly long, it is the third-longest European mountain range after the Ural Mountains, Urals at and the Scandinavian Mountains at . The ...

and other mountain ranges. Several horizons of the formation are particularly rich in

ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttle ...

fauna.

Fossil content

;Fish * '' Agkistracanthus sp.''Duffin & Furrer, 1981 ;AmmonitesBlau, 1998 * '' Echioceras raricostatoides'' * '' Epophioceras landrioti'' * '' Leptechioceras meigeni'' * '' Asteroceras cf. suevicum'' * '' Juraphyllites sp.'' * '' Paltechioceras sp.'' * ''Villania sp.'' ;RhynchonellataSulser & Furrer, 2008 * '' Carapezzia engadinensis'' * '' Sulcirostra doesseggeri'' * '' Sulcirostra cf. zitteli''

References

Bibliography

* Gawlick, H.J., Missoni, S., Schlagintweit, F., Suzuki, H., Frisch, W., Krystyn, L., Blau, J. & Lein, R., 2009, Jurassic Tectonostratigraphy of the Austroalpine Domain. Journal of Alpine Geology, 50, p. 1–152 * H. Sulser and H. Furrer. 2008. Dimerelloid rhynchonellide brachiopods in the Lower Jurassic of the Engadine (Canton Graubünden, National Park, Switzerland). Swiss Journal of Geosciences 101:203-222 * J. Blau. 1998. Monographie der Ammoniten des Obersinemuriums (Lotharingium, Lias) der Lienzer Dolomiten (Österreich): Biostratigraphie, Systematik und Paläobiogeographie. Revue de Paléobiologie, Genève 17:177-285 * C. J. Duffin and H. Furrer. 1981. Myriacanthid holocephalan remains from the Rhaetian (Upper Triassic) and Hettangian (Lower Jurassic) of Graubünden (Switzerland). Eclogae Geologicae Helvetiae 74:803-829 * Jacobshagen, V. von, 1965, Die Allgäu-Schichten (Jura-Fleckenmergel) zwischen Wettersteingebirge und Rhein. Jb. Geol. B. A., 108, pp. 1–114 {{DEFAULTSORT:Allgau Formation Geologic formations of Austria Geologic formations of Germany Geologic formations of Switzerland Jurassic System of Europe Jurassic Austria Jurassic Germany Hettangian Stage Sinemurian Stage Jurassic Switzerland Marl formations Limestone formations Open marine deposits Paleontology in Austria Paleontology in Germany Paleontology in Switzerland Northern Limestone Alps

Fossil content

See also

References

Bibliography