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Aalenian Stage
The Aalenian () is a subdivision of the Middle Jurassic Epoch/Series of the geologic timescale that extends from about 174.1 Ma to about 170.3 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 ammonite biozones: *z ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Commission On Stratigraphy
The International Commission on Stratigraphy (ICS), sometimes referred to unofficially as the "International Stratigraphic Commission", is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigraphy, stratigraphical, geology, geological, and chronology, geochronological matters on a global scale. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bajocian
In the geologic timescale, the Bajocian is an age and stage in the Middle Jurassic. It lasted from approximately 170.3 Ma to around 168.3 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 into Lower/Early ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biozone
In biostratigraphy, biostratigraphic units or biozones are intervals of geological strata that are defined on the basis of their characteristic fossil taxa, as opposed to a lithostratigraphic unit which is defined by the lithological properties of the surrounding rock. A biostratigraphic unit is defined by the zone fossils it contains. These may be a single taxon or combinations of taxa if the taxa are relatively abundant, or variations in features related to the distribution of fossils. The same strata may be zoned differently depending on the diagnostic criteria or fossil group chosen, so there may be several, sometimes overlapping, biostratigraphic units in the same interval. Like lithostratigraphic units, biozones must have a type section designated as a stratotype. These stratotypes are named according to the typical taxon (or taxa) that are found in that particular biozone. The boundary of two distinct biostratigraphic units is called a ''biohorizon''. Biozones can be furthe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tethys Ocean
The Tethys Ocean ( el, Τηθύς ''Tēthús''), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean that covered most of the Earth during much of the Mesozoic Era and early Cenozoic Era, located between the ancient continents of Gondwana and Laurasia, before the opening of the Indian and Atlantic oceans during the Cretaceous Period. It was preceded by the Paleo-Tethys Ocean, which lasted between the Cambrian and the Early Triassic, while the Neotethys formed during the Late Triassic and lasted until the early Eocene (about 50 million years ago) when it completely closed. A portion known as the Paratethys formed during the Late Jurassic, was isolated during the Oligocene (34 million years ago) and lasted up to the Pliocene (about 5 million years ago), when it largely dried out. Many major seas and lakes of Europe and Western Asia, including the Mediterranean Sea, the Black Sea, the Caspian Sea, and the Aral Sea are thought to be remnants of the Paratethys. Ety ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guadalajara (province)
Guadalajara () is a province of Spain, belonging to the autonomous community of Castilla–La Mancha. As of 2013 it had a population of 257,723 people. The population of the province has grown in the last 10 years. It is located in the centre of the Iberian Peninsula. History Prehistory The province has been inhabited since the Paleolithic as evidenced by stone tools found on the banks of the Henares and Linares rivers. There are also numerous prehistoric cave paintings in the Cueva de los Casares in Riba de Saelices while Megalithic tombs from the 4th millennium B.C. have been found at various sites in the province including Alcolea del Pinar. There are remains of several Bronze Age settlements along the river banks in the area, notably that in Loma del Lomo in Cogolludo as well as a late Bronze Age settlement in Mojares. Celtiberians and Romans The Celtiberians occupied the territory during the late Iron Age between the 6th and 3rd centuries B.C. in Sigüenza, Atienza, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Boundary Stratotype Section And Point
A Global Boundary Stratotype Section and Point (GSSP) 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 2022, 77 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 marker (usually first appearance datum of a fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 cuttlefish) than they are to shelled nautiloids such as the living ''Nautilus'' species. The earliest ammonites appeared during the Devonian, with the last species vanishing during the Cretaceous–Paleogene extinction event. Ammonites are excellent index fossils, and linking the rock layer in which a particular species or genus is found to specific geologic time periods is often possible. Their fossil shells usually take the form of planispirals, although some helically spiraled and nonspiraled forms (known as heteromorphs) have been found. The name "ammonite", from which the scientific term is derived, was inspired by the spiral shape of their fossilized shells, which somewhat resemble tightly coiled rams' horns. Pliny the Elder ( 79 AD near Pomp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karl Mayer-Eymar
Karl David Wilhelm Mayer-Eymar (29 July 1826 – 25 February 1907) was a Franco-Swiss paleontologist and geologist known for his work on classifying the stratigraphy of the Tertiary into 12 stages. He was born Karl Mayer but added the anagram Eymar around 1865 to distinguish his name from others, and the nickname "Tertiary Mayer" was also used. He was a major collector of fossils and described many molluscs. Son of a Swiss businessman Carl Friederich Mayer and Elisabeth Maria Fraziska Kunkler, he was born in Marseilles and was educated at Renne and St Gall before going to the University of Zurich in 1846. He then worked at the Museum d'Histoire Naturelle The French National Museum of Natural History, known in French as the ' (abbreviation MNHN), is the national natural history museum of France and a ' of higher education part of Sorbonne Universities. The main museum, with four galleries, is loc ... at Paris under Charles Henry Dessalines d'Orbigny. He moved to the Zurich Pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Switzerland
). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel, St. Gallen a.o.). , coordinates = , largest_city = Zürich , official_languages = , englishmotto = "One for all, all for one" , religion_year = 2020 , religion_ref = , religion = , demonym = , german: Schweizer/Schweizerin, french: Suisse/Suissesse, it, svizzero/svizzera or , rm, Svizzer/Svizra , government_type = Federalism, Federal assembly-independent Directorial system, directorial republic with elements of a direct democracy , leader_title1 = Federal Council (Switzerland), Federal Council , leader_name1 = , leader_title2 = , leader_name2 = Walter Thurnherr , legislature = Fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swabian Jura
The Swabian Jura (german: Schwäbische Alb , more rarely ), sometimes also named Swabian Alps in English, is a mountain range in Baden-Württemberg, Germany, extending from southwest to northeast and in width. It is named after the region of Swabia. The Swabian Jura occupies the region bounded by the Danube in the southeast and the upper Neckar in the northwest. In the southwest it rises to the higher mountains of the Black Forest. The highest mountain of the region is the Lemberg (). The area's profile resembles a high plateau, which slowly falls away to the southeast. The northwestern edge is a steep escarpment (called the Albtrauf or Albanstieg, rising up , covered with forests), while the top is flat or gently rolling. In economic and cultural terms, the Swabian Jura includes regions just around the mountain range. It is a popular recreation area. Geology The geology of the Swabian Jura is mostly limestone, which formed the seabed during the Jurassic period. The sea r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
