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Bajocian
In the geologic timescale, the Bajocian is an age and stage in the Middle Jurassic. It lasted from approximately 170.9 ±0.8 Ma to around 168.2 ±1.2 Ma (million years ago). The Bajocian Age succeeds the Aalenian Age and precedes the Bathonian Age. Stratigraphic definitions The Bajocian Stage takes its name from the Latin name (Bajocae) of the town of Bayeux, in the region of Normandy in France. The stage was named and introduced in scientific literature by French palaeontologist Alcide d'Orbigny in 1842. The base of the Bajocian stage is defined as the place in the stratigraphic column where fossils of the ammonite genus '' Hyperlioceras'' first appear. A global reference profile (a GSSP) for the base is located at Murtinheira, close to Cabo Mondego in Portugal.The GSSP is described by Pavia & Enay (1997) The top of the Bajocian (the base of the Bathonian) is at the first appearance of ammonite species ''Parkinsonia convergens''. Subdivision The Bajocian is often divided ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperlioceras
''Hyperlioceras'' is an extinct genus of cephalopod included in the ammonitid family Graphoceratidae that lived during the Bajocian stage of the Middle Jurassic. The type species is ''Hyperlioceras discites'' (Waagen, 18567) Morphology The shell of ''Hyperlioceras'' is very compressed and involute, with a tall persistent keel and a deep umbilicus. Biostratigraphic significance The International Commission on Stratigraphy (ICS) has defined the base of the Bajocian Stage of the Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ... as the lowest occurrence of the genus ''Hyperlioceras'', at 170.3 ± 1.4 million years ago, which defines base of the ''Hyperlioceras discites'' Zone. This point also marks the end of the preceding Aalenian Stage. The upper boundary of the Bajo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aalenian
The Aalenian () is a subdivision of the Middle Jurassic Epoch/Series of the geologic timescale that extends from about 174.7 ±0.8 Ma to about 170.9 ±0.8 Ma (million years ago). It was preceded by the Toarcian and succeeded by the Bajocian. Stratigraphic definitions The Aalenian takes its name from the town of Aalen, some 70 km east of Stuttgart in Germany. The town lies at the northeastern end of the Swabian Jura. The name Aalenian was introduced in scientific literature by Swiss geologist Karl Mayer-Eymar in 1864. The base of the Aalenian is defined as the place in the stratigraphic column where the ammonite genus '' Leioceras'' first appears. The global reference profile (GSSP) is located 500 meters north of the village of Fuentelsaz in the Spanish province of Guadalajara.Cresta ''et al.'' (2001) The top of the Aalenian (the base of the Bajocian) is at the first appearance of ammonite genus '' Hyperlioceras''. In the Tethys domain, the Aalenian contains four ammonit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Timescale
The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (a scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardised international units of geological time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to precise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garantiana
''Garantiana'' is a genus of ammonites from the Bajocian In the geologic timescale, the Bajocian is an age and stage in the Middle Jurassic. It lasted from approximately 170.9 ±0.8 Ma to around 168.2 ±1.2 Ma (million years ago). The Bajocian Age succeeds the Aalenian Age and precedes the Bathonia ... stage at the beginning of the Middle Jurassic, included in the family Stephanoceratidae. Description ''Garantiana'' is strongly ribbed and generally evolute. The inner whorls are exposed in a wide and fairly deep umbilicus. Ribs arise at the umbilical margin and split in two (bifurcate) about midway up the sides and cross over the outer (ventral) rim. ''Garantiana'' was named by d'Orbigny, 1845. The type species is ''Garantiana garantiana'', which comes from France. Related genera include '' Orthogarantiana'' '' Pseudogarantiana'', and '' Strenoceras''. References External links ''Garantiana''in Hildoceras webpag''Garaniana''pictured in the Fossil Foru Jurassic ammon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bayeux
Bayeux (, ; ) is a commune in the Calvados department in Normandy in northwestern France. Bayeux is the home of the Bayeux Tapestry, which depicts the events leading up to the Norman Conquest of England in 1066. It is also known as the first major town secured by the Allies during Operation Overlord after D-Day. Charles de Gaulle made two famous speeches in this town. Administration Bayeux is a sub-prefecture of Calvados. It is the seat of the arrondissement of Bayeux and of the canton of Bayeux. Geography Bayeux is located from the coast of the English Channel and north-west of Caen. The city, with elevations varying from above sea level – with an average of – is bisected by the River Aure. Bayeux is located at the crossroads of RN 13 and the train route Paris-Caen-Cherbourg. The city is the capital of the Bessin, which extends north-west of Calvados. Bayeux station has rail connections to Caen, Cherbourg, Granville and Paris. The river Aure flows throug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Jurassic
The Middle Jurassic is the second Epoch (geology), epoch of the Jurassic Period (geology), Period. It lasted from about 174.1 to 161.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations containing land animal fossils include the Forest Marble Formation in England, the Kilmaluag Formation in Scotland,British Geological Survey. 2011Stratigraphic framework for the Middle Jurassic strata of Great Britain and the adjoining continental shelf: research report RR/11/06 British Geological Survey, Keyworth, Nottingham. the Calcaire de Caen of France, the Daohugou Beds in China, the Itat Formation in Russia, the Tiouraren Formation of Niger, and the Isalo III Formation of western Madagascar. Rocks of the Middle Jurassic were formerly (until about 1980s) in Europe called ''Dogger'' or ''Brown Jurassic''. Paleogeography During the Middle Jurassic Epoch, Pangaea began to separate into Laurasia and Gond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSSP
A Global Boundary Stratotype Section and Point (GSSP), sometimes referred to as a golden spike, is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundary of a stage on the geologic time scale. The effort to define GSSPs is conducted by the International Commission on Stratigraphy, a part of the International Union of Geological Sciences. Most, but not all, GSSPs are based on paleontological changes. Hence GSSPs are usually described in terms of transitions between different faunal stages, though far more faunal stages have been described than GSSPs. The GSSP definition effort commenced in 1977. As of 2024, 79 of the 101 stages that need a GSSP have a ratified GSSP. Rules A geologic section has to fulfill a set of criteria to be adapted as a GSSP by the ICS. The following list summarizes the criteria: * A GSSP has to define the lower boundary of a geologic stage. * The lower boundary has to be defined using a primary m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathonian
In the geologic timescale the Bathonian is an age (geology), age and stage (stratigraphy), stage of the Middle Jurassic. It lasted from approximately 168.2 ±1.2 annum, Ma to around 165.3 ±1.1 Ma (million years ago). The Bathonian Age succeeds the Bajocian Age and precedes the Callovian Age. Stratigraphic definitions The Bathonian Stage takes its name from Bath, Somerset, Bath, a spa town in England built on Jurassic limestone (the Latinized form of the town name is ''Bathonium''). The name was introduced in scientific literature by Belgian geologist Jean Baptiste Julien d'Omalius d'Halloy, d'Omalius d'Halloy in 1843. The original type locality (geology), type locality was located near Bath. The French palaeontologist Alcide d'Orbigny was in 1852 the first to define the exact length of the stage. The base of the Bathonian is at the first appearance of ammonite species ''Parkinsonia (ammonite), Parkinsonia (Gonolkites) convergens'' in the stratigraphic column. The global referen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normandy
Normandy (; or ) is a geographical and cultural region in northwestern Europe, roughly coextensive with the historical Duchy of Normandy. Normandy comprises Normandy (administrative region), mainland Normandy (a part of France) and insular Normandy (mostly the British Channel Islands). It covers . Its population in 2017 was 3,499,280. The inhabitants of Normandy are known as Normans; the region is the historic homeland of the Norman language. Large settlements include Rouen, Caen, Le Havre and Cherbourg-en-Cotentin, Cherbourg. The cultural region of Normandy is roughly similar to the historical Duchy of Normandy, which includes small areas now part of the departments of Mayenne and Sarthe. The Channel Islands (French: ''Îles Anglo-Normandes'') are also historically part of Normandy; they cover and comprise two bailiwicks: Bailiwick of Guernsey, Guernsey and Jersey, which are British Crown Dependencies. Normandy's name comes from the settlement of the territory by Vikings ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Commission On Stratigraphy
The International Commission on Stratigraphy (ICS), sometimes unofficially referred to as the International Stratigraphic Commission, is a daughter or major subcommittee grade scientific organization that concerns itself with stratigraphy, stratigraphical, geology, geological, and chronology, geochronological matters, worldwide. It is the largest subordinate body of the International Union of Geological Sciences (IUGS). The ICS is essentially a permanent working committee, working subcommittee, which meets far more regularly than the quadrennial meetings scheduled by the IUGS, when it meets as a congress or committee, membership of the whole. Aims One of its main aims, a project begun in 1974, is to establish a multidisciplinary standard and global geologic time scale that will ease paleontology, paleontological and geobiology, geobiological comparisons region to region by benchmarks with stringent and rigorous strata criteria called Global Boundary Stratotype Section and Points ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcide D'Orbigny
Alcide Charles Victor Marie Dessalines d'Orbigny (6 September 1802 – 30 June 1857) was a French naturalist who made major contributions in many areas, including zoology (including malacology), palaeontology, geology, archaeology and anthropology. D'Orbigny was born in Couëron (Loire-Atlantique), the son of a ship's physician and amateur naturalist. The family moved to La Rochelle in 1820, where his interest in natural history was developed while studying the marine fauna and especially the microscopic creatures that he named "foraminiferans". In Paris he became a disciple of the geologist Louis Cordier, Pierre Louis Antoine Cordier (1777–1861) and Georges Cuvier. All his life, he would follow the theory of Cuvier and stay opposed to Lamarckism. South American era D'Orbigny travelled on a mission for the Paris Museum, in South America between 1826 and 1833. He visited Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, Argentina, Paraguay, and Brazil, and returned to Franc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
