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Santonian Genus First Appearances
The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. The Santonian is preceded by the Coniacian and is followed by the Campanian.Gradstein ''et al.'' (2004) Stratigraphic definition The Santonian Stage was established by French geologist Henri Coquand in 1857. It is named after the city of Saintes in the region of Saintonge, where the original type locality is located. The base of the Santonian Stage is defined by the appearance of the inoceramid bivalve '' Cladoceramus undulatoplicatus''. The GSSP (official reference profile) for the base of the Santonian Stage is located near Olazagutia, Spain; it was ratified by the Subcommission on Cretaceous Stratigraphy in 2012. The Santonian's top (the base of the Campanian Stage) is informally marked by the extinction of the crinoid '' Marsupit ... [...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 stratigraphical, geological, and 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 subcommittee, which meets far more regularly than the quadrennial meetings scheduled by the IUGS, when it meets as a congress or 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 paleontological and geobiological comparisons region to region by benchmarks with stringent and rigorous strata criteria called Global Boundary Stratotype Section and Points (GSSPs) within the fossil record. (i.e. section of the rock rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Age (geology)
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 (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 standardized international units of geologic 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 precisely de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saintes, Charente-Maritime
Saintes (; Poitevin-Saintongeais: ''Sénte'') is a commune and historic town in western France, in the Charente-Maritime department of which it is a sub-prefecture, in Nouvelle-Aquitaine. Its inhabitants are called ''Saintaises'' and ''Saintais''. Saintes is the second-largest city in Charente-Maritime, with inhabitants in 2008. The city's immediate surroundings form the second-most populous metropolitan area in the department, with inhabitants. While a majority of the surrounding landscape consists of fertile, productive fields, a significant minority of the region remains forested, its natural state. In Roman times, Saintes was known as '' Mediolanum Santonum''. During much of its history, the name of the city was spelled Xaintes or Xainctes. Primarily built on the left bank of the Charente, Saintes became the first Roman capital of Aquitaine. Later it was designated as the capital of the province of Saintonge under the Ancien Régime. Following the French Revolution, it b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henri Coquand
Henri Coquand (1813, in Aix-en-Provence – 1881, in Marseille) was a French geologist and paleontologist. In 1841 he obtained his doctorate in sciences in Paris, and later served as a professor of geology at the University of Besançon, Poitiers and Marseille.Prosopo Sociétés savantes From his geological studies of southwestern France, he introduced the stages: , and |
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area extends from the Rhine to the Atlantic Ocean and from the Mediterranean Sea to the English Channel and the North Sea; overseas territories include French Guiana in South America, Saint Pierre and Miquelon in the North Atlantic, the French West Indies, and many islands in Oceania and the Indian Ocean. Due to its several coastal territories, France has the largest exclusive economic zone in the world. France borders Belgium, Luxembourg, Germany, Switzerland, Monaco, Italy, Andorra, and Spain in continental Europe, as well as the Netherlands, Suriname, and Brazil in the Americas via its overseas territories in French Guiana and Saint Martin. Its eighteen integral regions (five of which are overseas) span a combined area of and contain clos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian spans the time from 83.6 (± 0.2) to 72.1 (± 0.2) million years ago. It is preceded by the Santonian and it is followed by the Maastrichtian. The Campanian was an age when a worldwide sea level rise covered many coastal areas. The morphology of some of these areas has been preserved: it is an unconformity beneath a cover of marine sedimentary rocks. Etymology The Campanian was introduced in scientific literature by Henri Coquand in 1857. It is named after the French village of Champagne in the department of Charente-Maritime. The original type locality was a series of outcrop near the village of Aubeterre-sur-Dronne in the same region. Definition The base of the Campanian Stage is defined as a place in the stratigraphic colu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coniacian
The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma (million years ago). The Coniacian is preceded by the Turonian and followed by the Santonian. Stratigraphic definitions The Coniacian is named after the city of Cognac in the French region of Saintonge. It was first defined by French geologist Henri Coquand in 1857. The base of the Coniacian Stage is at the first appearance of the inoceramid bivalve species '' Cremnoceramus deformis erectus''. The official reference profile for the base (a GSSP) is located in Salzgitter-Salder, Lower Saxony, Germany. The top of the Coniacian (the base of the Santonian Stage) is defined by the appearance of the inoceramid bivalve ''Cladoceramus undulatoplicatus''. The Coniacian overlaps the regional Emscherian Stage of Germany, which is roughly coeval with the Coniacian and Santonian Stages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Million Years Ago
The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). Together they make a reference system, one to a quantity, the other to a particular place in a year numbering system that is ''time before the present''. Myr is deprecated in geology, but in astronomy ''Myr'' is standard. Where "myr" ''is'' seen in geology it is usually "Myr" (a unit of mega-years). In astronomy it is usually "Myr" (Million years). Debate In geology a debate remains open concerning the use of ''Myr'' (duration) plus ''Ma'' (million years ago) versus using only the term ''Ma''. In either case the term '' Ma'' is used in geology literature conforming to ISO 31-1 (now ISO 80000-3) and NIST 811 recommended practices. Traditional style geology literature is written The "ago" is implied, so that any such year number "X Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Series (stratigraphy)
Series are subdivisions of rock layers based on the age of the rock and formally defined by international conventions of the geological timescale. A series is therefore a sequence of strata defining a chronostratigraphic unit. Series are subdivisions of systems and are themselves divided into stages. Series is a term defining a unit of rock layers formed during a certain interval of time (a chronostratigraphic unit); it is equivalent (but not synonymous) to the term ''geological epoch'' (see epoch criteria) which defines the interval of time itself, although the two words are sometimes confused in informal literature. Series in the geological timescale The geological timescale has all systems in the Phanerozoic eonothem subdivided into series. Some of these have their own names, in other cases a system is simply divided into a Lower, Middle and Upper series. The Cretaceous system is for example divided into the Upper Cretaceous and Lower Cretaceous series; while the Carbonif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoch (geology)
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 (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 standardized international units of geologic 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 precisely de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
