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Stanley Awramik
Stanley Awramik (born 1946) is an American biogeologist and paleontologist. He is best known for his work related to the Precambrian. In 2013, he was inducted as a fellow of the Geological Society of America. Career Born in New England, he first studied stromatolites as a graduate student under famed paleobotanist Elso Sterrenberg Barghoorn at Harvard University. In 1979, he became a faculty member at the University of California, Santa Barbara, where he was a contemporary of Preston Cloud. Stromatolites Awramik is known for his long standing expertise on stromatolites. His 1971 discovery of a link between a loss in stromatolitic diversity and the appearance of the first metazoans was published in ''Science''. In 1974, he and Lynn Margulis gave an often-used definition of "stromatolite". Origin of life In 1983, he discovered what was then considered to be the oldest evidence of life on earth, located in Western Australia. His and others' work provided credence to the notion tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biogeology
Biogeology is the study of the interactions between the Earth's biosphere and the lithosphere. Biogeology examines biotic, hydrologic, and terrestrial systems in relation to each other, to help understand the Earth's climate, oceans, and other effects on geologic systems. For example, bacteria are responsible for the formation of some minerals such as pyrite, and can concentrate economically important metals such as tin and uranium. Bacteria are also responsible for the chemical composition of the atmosphere, which affects weathering rates of rocks. Prior to the late Devonian period, there was little plant life beyond lichens, and bryophytes. At this time large vascular plants evolved, growing up to in height. These large plants changed the atmosphere, and altered the composition of the soil by increasing the amount of organic carbon. This helped prevent the soil being washed away through erosion. See also *Pedology *Geobiology References External links Biogeology departmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stromatolite
Stromatolites () or stromatoliths () are layered sedimentary formations (microbialite) that are created mainly by photosynthetic microorganisms such as cyanobacteria, sulfate-reducing bacteria, and Pseudomonadota (formerly proteobacteria). These microorganisms produce adhesive compounds that cement sand and other rocky materials to form mineral "microbial mats". In turn, these mats build up layer by layer, growing gradually over time. A stromatolite may grow to a meter or more. Although they are rare today, fossilized stromatolites provide records of ancient life on Earth. Morphology Stromatolites are layered, biochemical, accretionary structures formed in shallow water by the trapping, binding and cementation of sedimentary grains in biofilms (specifically microbial mats), through the action of certain microbial lifeforms, especially cyanobacteria. They exhibit a variety of forms and structures, or morphologies, including conical, stratiform, domal, columnar, and branching ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fellows Of The Geological Society Of America
{{disambiguation ...
Fellows may refer to Fellow, in plural form. Fellows or Fellowes may also refer to: Places * Fellows, California, USA * Fellows, Wisconsin, ghost town, USA Other uses * Fellows Auctioneers, established in 1876. *Fellowes, Inc., manufacturer of workspace products *Fellows, a partner in the firm of English canal carriers, Fellows Morton & Clayton * Fellows (surname) See also *North Fellows Historic District, listed on the National Register of Historic Places in Wapello County, Iowa *Justice Fellows (other) Justice Fellows may refer to: * Grant Fellows (1865–1929), associate justice of the Michigan Supreme Court * Raymond Fellows (1885–1957), associate justice of the Maine Supreme Judicial Court {{disambiguation, tndis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of California, Santa Barbara Faculty
A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, the designation is reserved for colleges that have a graduate school. The word ''university'' is derived from the Latin ''universitas magistrorum et scholarium'', which roughly means "community of teachers and scholars". The first universities were created in Europe by Catholic Church monks. The University of Bologna (''Università di Bologna''), founded in 1088, is the first university in the sense of: *Being a high degree-awarding institute. *Having independence from the ecclesiastic schools, although conducted by both clergy and non-clergy. *Using the word ''universitas'' (which was coined at its foundation). *Issuing secular and non-secular degrees: grammar, rhetoric, logic, theology, canon law, notarial law.Hunt Janin: "The university i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harvard University Alumni
The list of Harvard University people includes notable graduates, professors, and administrators affiliated with Harvard University. For a list of notable non-graduates of Harvard, see notable non-graduate alumni of Harvard. For a list of Harvard's presidents, see President of Harvard University. Eight President of the United States, Presidents of the United States have graduated from Harvard University: John Adams, John Quincy Adams, Rutherford B. Hayes, John F. Kennedy, Franklin Delano Roosevelt, Theodore Roosevelt, George W. Bush, and Barack Obama. Bush graduated from Harvard Business School, Hayes and Obama from Harvard Law School, and the others from Harvard College. Over 150 Nobel Prize winners have been associated with the university as alumni, researchers or faculty. Nobel laureates Pulitzer Prize winners ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Paleontologists
American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, people who self-identify their ancestry as "American" ** American English, the set of varieties of the English language native to the United States ** Native Americans in the United States, indigenous peoples of the United States * American, something of, from, or related to the Americas, also known as "America" ** Indigenous peoples of the Americas * American (word), for analysis and history of the meanings in various contexts Organizations * American Airlines, U.S.-based airline headquartered in Fort Worth, Texas * American Athletic Conference, an American college athletic conference * American Recordings (record label), a record label previously known as Def American * American University, in Washington, D.C. Sports teams Soccer * B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlanta
Atlanta ( ) is the capital and most populous city of the U.S. state of Georgia. It is the seat of Fulton County, the most populous county in Georgia, but its territory falls in both Fulton and DeKalb counties. With a population of 498,715 living within the city limits, it is the eighth most populous city in the Southeast and 38th most populous city in the United States according to the 2020 U.S. census. It is the core of the much larger Atlanta metropolitan area, which is home to more than 6.1 million people, making it the eighth-largest metropolitan area in the United States. Situated among the foothills of the Appalachian Mountains at an elevation of just over above sea level, it features unique topography that includes rolling hills, lush greenery, and the most dense urban tree coverage of any major city in the United States. Atlanta was originally founded as the terminus of a major state-sponsored railroad, but it soon became the convergence point among several rai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrobiology
Astrobiology, and the related field of exobiology, is an interdisciplinary scientific field that studies the origins, early evolution, distribution, and future of life in the universe. Astrobiology is the multidisciplinary field that investigates the deterministic conditions and contingent events with which life arises, distributes, and evolves in the universe. Astrobiology makes use of molecular biology, biophysics, biochemistry, chemistry, astronomy, physical cosmology, exoplanetology, geology, paleontology, and ichnology to investigate the possibility of life on other worlds and help recognize biospheres that might be different from that on Earth. The origin and early evolution of life is an inseparable part of the discipline of astrobiology. Astrobiology concerns itself with interpretation of existing scientific data, and although speculation is entertained to give context, astrobiology concerns itself primarily with hypotheses that fit firmly into existing scientific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snowball Earth
The Snowball Earth hypothesis proposes that, during one or more of Earth's Greenhouse and icehouse Earth, icehouse Climate, climates, the Earth's surface, planet's surface became entirely or nearly entirely Freezing, frozen. It is believed that this occurred sometime before 650 M.Y.A. (million years ago) during the Cryogenian period. Proponents of the hypothesis argue that it best explains sedimentary Deposition (geology), deposits that are generally believed to be of glacial origin at tropical palaeolatitudes and other enigmatic features in the geological record. Opponents of the hypothesis contest the geological evidence for Glacial period, global glaciation and the geophysical feasibility of an ice- or slush-covered ocean, and they emphasize the difficulty of escaping an all-frozen condition. A number of unanswered questions remain, including whether Earth was a full snowball or a "slushball" with a thin Equator, equatorial band of open (or seasonally open) water. The snowball ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryogenian
The Cryogenian (from grc, κρύος, krýos, meaning "cold" and , romanized: , meaning "birth") is a geologic period that lasted from . It forms the second geologic period of the Neoproterozoic Era, preceded by the Tonian Period and followed by the Ediacaran. Cryogenian was the time of drastic biosphere changes. After the previous Boring Billion years of stability, at the beginning of Cryogenian the severe Sturtian glaciation began, freezing the entire Earth in a planetary state known as a Snowball Earth. After 70 million years it ended, but was quickly followed by the Marinoan glaciation, which was also a global event. These events are the subject of much scientific controversy specifically over whether these glaciations covered the entire planet or a band of open sea survived near the equator (termed "slushball Earth"). Ratification The Cryogenian Period was ratified in 1990 by the International Commission on Stratigraphy. In contrast to most other time periods, the beginni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proceedings Of The National Academy Of Sciences Of The United States Of America
''Proceedings of the National Academy of Sciences of the United States of America'' (often abbreviated ''PNAS'' or ''PNAS USA'') is a peer-reviewed multidisciplinary scientific journal. It is the official journal of the National Academy of Sciences, published since 1915, and publishes original research, scientific reviews, commentaries, and letters. According to ''Journal Citation Reports'', the journal has a 2021 impact factor of 12.779. ''PNAS'' is the second most cited scientific journal, with more than 1.9 million cumulative citations from 2008 to 2018. In the mass media, ''PNAS'' has been described variously as "prestigious", "sedate", "renowned" and "high impact". ''PNAS'' is a delayed open access journal, with an embargo period of six months that can be bypassed for an author fee ( hybrid open access). Since September 2017, open access articles are published under a Creative Commons license. Since January 2019, ''PNAS'' has been online-only, although print issues are ava ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoproterozoic
The Neoproterozoic Era is the unit of geologic time from 1 billion to 538.8 million years ago. It is the last era of the Precambrian Supereon and the Proterozoic Eon; it is subdivided into the Tonian, Cryogenian, and Ediacaran periods. It is preceded by the Mesoproterozoic Era and succeeded by the Paleozoic Era of the Phanerozoic Eon. The most severe glaciation known in the geologic record occurred during the Cryogenian, when ice sheets may have reached the equator and formed a " Snowball Earth". The earliest fossils of complex multicellular life are found in the Ediacaran Period. These organisms make up the Ediacaran biota, including the oldest definitive animals in the fossil record. According to Rino and co-workers, the sum of the continental crust formed in the Pan-African orogeny and the Grenville orogeny makes the Neoproterozoic the period of Earth's history that has produced most continental crust. Geology At the onset of the Neoproterozoic the supercontine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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