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Latest Danian Event
The Latest Danian Event (LDE) was a hyperthermal event that occurred at the end of the Danian stage. Timing The LDE is believed to have been approximately 170-230 kyr in duration and occurred about 62.18 Ma. The LDE consisted of two distinct ''δ''13C excursions, which are referred to as LDE1 and LDE2, respectively. Effects The LDE was similar in essence to the Palaeocene-Eocene Thermal Maximum (PETM), although significantly smaller in magnitude. Seawater warmed by about 2-3 °C in both the surface oceans and the deep oceans. The LDE led to a significant shoaling of the oceanic lysocline, which is evidenced by the greatly reduced calcium carbonate preservation that occurred during the event. Significant black shale deposition occurred during the LDE, a consequence of sea level rise and clastic starvation combined with enhanced nutrient input into the ocean and anoxia. The planktonic foraminifer genus ''Morozovella'', especially the species ''M. angulata'', increased in abu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperthermal Event
A hyperthermal event corresponds to a sudden warming of the planet on a geologic time scale. The consequences of this type of event are the subject of numerous studies because they can constitute an analogue of current global warming. Hyperthermal events The first event of this type was described in 1991 from a sediment core extracted from a drilling of the Ocean Drilling Program (ODP) carried out in Antarctica in the Weddell Sea. This event occurs at the boundary of the Paleocene and Eocene epochs approximately 56 million years ago. It is now called the Paleocene-Eocene Thermal Maximum (PETM). During this event, the temperature of the oceans increased by more than 5 °C in less than 10,000 years. Since this discovery, several other hyperthermal events have been identified in this lower part of the Paleogene geological period: * the Dan-C2 event at the beginning of the Danian stage of the Paleocene, about 65.2 million years ago, quite the basis of the Cenozoic era; * the D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. 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 of an ancestral taxon are grouped together (i.e. Phylogeneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Lutetian Thermal Maximum
The Late Lutetian Thermal Maximum (LLTM), also known as the C19r Event, was a hyperthermal event that occurred during the Lutetian epoch. Timing The LLTM occurred about 41.52 Ma, amidst a broader cooling trend known as the Middle-Late Eocene Cooling (MLEC), and lasted for about 30 kyr. It is believed to have been a globally synchronous event. Causes The LLTM coincided with exceptionally high insolation of the Northern Hemisphere caused by the coincidence of a precession minimum modulated by high eccentricity and an obliquity maximum, which also cooccurred with maxima in the 2.4 Myr eccentricity cycle and the 1.2 Myr obliquity cycle. Effects The high solar irradiance experienced by the Earth during the LLTM caused an acceleration of the water cycle, increasing the rate of runoff and input of terrestrial sediment into the ocean. This resulted in the freshening and eutrophication Eutrophication is a general term describing a process in which nutrients accumulate in a bod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene Thermal Maximum 2
Eocene Thermal Maximum 2 (ETM-2), also called H-1 or Elmo (Eocene Layer of Mysterious Origin), was a transient period of global warming that occurred around 54 Ma. It was the second major hyperthermal that punctuated long-term warming from the Late Paleocene through the Early Eocene (58 to 50 Ma). Timing ETM-2 occurred exactly 4.5 long eccentricity cycles after the PETM. ETM-2 is clearly recognized in sediment sequences by analyzing the stable carbon isotope composition of carbon-bearing material. The 13C/ 12C ratio of calcium carbonate or organic matter drops significantly across the event. This is similar to what happens when one examines sediment across the PETM, although the magnitude of the negative carbon isotope excursion is not as large during ETM-2. The timing of Earth system perturbations during ETM-2 and PETM also appear different. Specifically, the onset of ETM-2 may have been longer (perhaps 30,000 years) while the recovery seems to have been shorter (perhaps <50,00 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Today
''Geology Today'' is a bimonthly peer-reviewed scientific journal published by Wiley on behalf of the Geologists' Association and the Geological Society of London. The editor-in-chief is Peter Doyle (Geological Society of London). The journal covers all aspects of the Earth sciences. Abstracting and indexing The journal is abstracted and indexed in Aquatic Sciences and Fisheries Abstracts, EBSCO databases, ProQuest databases, Scopus, and The Zoological Record ''The Zoological Record'' (''ZR'') is an electronic index of zoological literature that also serves as the unofficial register of scientific names in zoology. It was started as a print publication in 1864 by the Zoological Society of London, .... References External links * Geology journals Wiley (publisher) academic journals Geological Society of London academic journals Academic journals established in 1985 Geologists' Association 1985 establishments in the United Kingdom {{geology-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Era (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 (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 precisely de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenozoic
The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three geological eras of the Phanerozoic Eon, preceded by the Mesozoic and Paleozoic. The Cenozoic started with the Cretaceous–Paleogene extinction event, when many species, including the non-avian dinosaurs, became extinct in an event attributed by most experts to the impact of a large asteroid or other celestial body, the Chicxulub impactor. The Cenozoic is also known as the Age of Mammals because the terrestrial animals that dominated both hemispheres were mammalsthe eutherians ( placentals) in the Northern Hemisphere and the metatherians (marsupials, now mainly restricted to Australia and to some extent South America) in the Southern Hemisphere. The extinction of many groups allowed mammals and birds to greatly diversify so that large m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytodetritus
In oceanography, phytodetritus is the organic particulate matter resulting from phytoplankton and other organic material in surface waters falling to the seabed. This process takes place almost continuously as a "marine snow" of descending particles, falling at the rate of about per day. Under certain conditions, phytoplankton may aggregate and fall rapidly through the water column to arrive little changed on the seabed. These fluxes sometimes occur seasonally or periodically, are sometimes associated with algal blooms and may constitute the greater part of descending organic matter. If the amount is greater than the benthic detritivores can process, the phytodetritus forms a fluffy layer on the surface of the sediment. It accumulates in many shallow and deep water locations throughout the world. Phytodetritus varies in colour and appearance and may be greenish, brown or grey, flocculent or gelatinous. It includes the microscopic remains of diatoms, dinoflagellates, dictyochales, c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shatsky Rise
The Shatsky Rise is Earth's third largest oceanic plateau, (after Ontong Java and Kerguelen) located in the north-west Pacific Ocean east of Japan. It is one of a series of Pacific Cretaceous large igneous provinces (LIPs) together with Hess Rise, Magellan Rise, and Ontong Java-Manihiki-Hikurangi. It was named for Nikolay Shatsky (1895-1960), a Soviet geologist, expert in tectonics of ancient platforms. The rise consists of three large volcanic massifs, Tamu, Ori, and Shirshov, but, in contrast, there are few traces of magmatism on the surrounding ocean floor. Tamu Massif is likely the largest volcano yet discovered on Earth. In 2016, a study found that Tamu Massif covered the entire Shatsky Rise, meaning that the volcano had a surface area of , surpassing Olympus Mons in terms of surface area. Extent and volume The central area of the Shatsky Rise is a diagonal plateau that extends from about 32–38° N. and 156–164° E. Including its periphery and the Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. Other ways of defining species include their karyotype, DNA sequence, morphology (biology), morphology, behaviour, or ecological niche. In addition, palaeontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. About 14% of these had been described by 2011. All species (except viruses) are given a binomial nomenclature, two-part name, a "binomen". The first part of a binomen is the name of a genus to which the species belongs. The second part is called the specific name (zoology), specific name or the specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planktonic Foraminifera
Plankton are the diverse collection of organisms that drift in water (or air) but are unable to actively propel themselves against currents (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish, and baleen whales. Marine plankton include bacteria, archaea, algae, protozoa, microscopic fungi, and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found in lakes and rivers. Mostly, plankton just drift where currents take them, though some, like jellyfish, swim slowly but not fast enough to generally overcome the influence of currents. Although plankton are usually thought of as inhabiting water, there are also airborne versions that live part of their lives drifting in the atmosphere. These ''aeroplankton'' include plant spo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
