Sinemurian Stage

Sinemurian Stage

      second of the four divisions of the Lower Jurassic Series, representing all rocks formed worldwide during the Sinemurian Age, which occurred between 196.5 million and 189.6 million years ago during the Early Jurassic Period. The Sinemurian Stage overlies the Hettangian Stage and underlies the Pliensbachian Stage.

      The Sinemurian Stage was named for exposures at Semur (the ancient Roman town of Sinemurum) in northeastern France, where a condensed sequence of limestones (limestone) contains fossils of ammonites (ammonoid) that lived during this time interval. In northwestern Europe, six major ammonite biozones (biozone) have been recognized for the Lower and Upper Sinemurian. Because Sinemurian ammonites are less geographically differentiated than earlier Jurassic forms, theoretically there should be more possibilities for large-scale regional stratigraphic correlations. However, many of the ammonite species are rare outside of northwestern Europe, and detailed fine-scale correlations and temporal divisions have not yet been developed for most regions around the world.

Carol Marie Tang
 

* * *


Universalium. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • Sinemurian — The Sinemurian is a stage of the Early Jurassic Epoch. It spans the time between 196.5 ± 2 Ma and 189.6 ± 1.5 Ma (million years ago).The stage takes its name from the town of Semur en Brionnais, near Sancerre in the upper Loire Valley. The… …   Wikipedia

  • Pliensbachian Stage — ▪ geology       third of the four divisions of the Lower Jurassic Series, representing all rocks formed worldwide during the Pliensbachian Age, which occurred between 189.6 million and 183 million years ago during the Early Jurassic Period. The… …   Universalium

  • Hettangian Stage — ▪ geology       lowest of the four divisions of the Lower Jurassic Series, representing all rocks formed worldwide during the Hettangian Age, which occurred between 199.6 million and 196.5 million years ago during the Early Jurassic Period. The… …   Universalium

  • Oxfordian (stage) — System Series Stage Age (Ma) Cretaceous Lower Berriasian younger Jurassic Upper Tith …   Wikipedia

  • Jurassic Period — Interval of geologic time, 206–144 million years ago, that is one of the three major divisions of the Mesozoic Era, preceded by the Triassic Period and followed by the Cretaceous. During the Jurassic, Pangea began to break up into the present day …   Universalium

  • Excalibosaurus — Taxobox name = Excalibosaurus fossil range = Early Jurassic image width=250px image caption= Excalibosaurus costini regnum = Animalia phylum = Chordata classis = Sauropsida ordo = Ichthyosauria subordo = Eurhinosauria familia = Leptopterygiidae… …   Wikipedia

  • Dilophosaurus — Unikonta Dilophosaurus Temporal range: Early Jurassic, 193 Ma …   Wikipedia

  • Hadrocodium — Taxobox name = Hadrocodium fossil range = Early Jurassic regnum = Animalia image width = 250px image caption = Hadrocodium skull phylum = Chordata subphylum = Vertebrata unranked classis = Amniota classis = Synapsida unranked ordo =… …   Wikipedia

  • Liassaurus — is the informal name given to an as yet undescribed genus of dinosaur from the Early Jurassic. It was a probable ceratosaur which lived in what is now Europe. The type species, L. huenei , was coined by Welles, H.P. Powell, and Stephan Pickering… …   Wikipedia

  • Merosaurus — is the informal name given to an as yet undescribed genus of dinosaur from the Early Jurassic (Sinemurian stage, around 190 million years ago). It was a tetanuran theropod which lived in what is now England. The type species, Merosaurus newmani …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”