|
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 de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stromatolite
Stromatolites ( ) or stromatoliths () are layered Sedimentary rock, sedimentary formation of rocks, formations (microbialite) that are created mainly by Photosynthesis, photosynthetic microorganisms such as cyanobacteria, sulfate-reducing microorganism, sulfate-reducing bacteria, and Pseudomonadota (formerly proteobacteria). These microorganisms produce adhesive compounds that cementation (geology), cement sand and other rocky materials to form mineral "microbial mats". In turn, these mats build up layer by layer, growing gradually over time. This process generates the characteristic Lamination (geology), lamination of stromatolites, a feature that is hard to interpret, in terms of its temporal and environmental significance. Different styles of stromatolite lamination have been described, which can be studied through microscopic and mathematical methods. A stromatolite may grow to a meter or more. Fossilized stromatolites provide important records of some of the most ancient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fellows Of The Geological Society Of America
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 * Fellowes, Inc., manufacturer of workspace products *Fellows, a partner in the firm of English canal carriers, Fellows Morton & Clayton *Fellows (surname) *Mount Fellows, a mountain in Alaska See also *North Fellows Historic District The North Fellows Historic District is a historic district located in Ottumwa, Iowa, United States. The city experienced a housing boom after World War II. This north side neighborhood of single-family brick homes built between 1945 and 1959 ..., listed on the National Register of Historic Places in Wapello County, Iowa * Justice Fellows (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of California, Santa Barbara Faculty
A university () is an institution of tertiary education and research which awards academic degrees in several academic disciplines. ''University'' is derived from the Latin phrase , which roughly means "community of teachers and scholars". Universities typically offer both undergraduate and postgraduate programs. The first universities in Europe were established by Catholic Church, Catholic monks. The University of Bologna (), Italy, which was founded in 1088, is the first university in the sense of: *being a high degree-awarding institute. *using the word (which was coined at its foundation). *having independence from the ecclesiastic schools and issuing secular as well as non-secular degrees (with teaching conducted by both clergy and non-clergy): grammar, rhetoric, logic, theology, canon law and notarial law.Hunt Janin: "The university in medieval life, 1179–1499", McFarland, 2008, , p. 55f.de Ridder-Symoens, Hilde''A History of the University in Europe: Volume 1, Universi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harvard University Alumni
The list of Harvard University alumni includes notable graduates, professors, and administrators affiliated with Harvard University. For a list of notable non-graduates of Harvard, see the list of Harvard University non-graduate alumni. For a list of Harvard's presidents, see President of Harvard University. Eight 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 that was previously known as Def American * American University, in Washington, D.C. Sports teams S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlanta
Atlanta ( ) is the List of capitals in the United States, capital and List of municipalities in Georgia (U.S. state), most populous city in the U.S. state of Georgia (U.S. state), Georgia. It is the county seat, seat of Fulton County, Georgia, Fulton County and extends into neighboring DeKalb County, Georgia, DeKalb County. With a population of 520,070 (2024 estimate) living within the city limits, Atlanta is the eighth most populous city in the Southeastern United States, Southeast and List of United States cities by population, 36th most populous city in the United States according to the 2020 United States census, 2020 U.S. census. Atlanta is classified as a Globalization and World Cities Research Network#Beta +, Beta + global city and is the principal city of the much larger Atlanta metropolitan area, the core of which includes Cobb County, Georgia, Cobb, Clayton County, Georgia, Clayton and Gwinnett County, Georgia, Gwinnett counties, in addition to Fulton and DeKalb. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrobiology
Astrobiology (also xenology or exobiology) is a scientific field within the List of life sciences, life and environmental sciences that studies the abiogenesis, origins, Protocell, early evolution, distribution, and future of life in the universe by investigating its deterministic conditions and contingent events. As a discipline, astrobiology is founded on the premise that life may exist beyond Earth. Research in astrobiology comprises three main areas: the study of planetary habitability, habitable environments in the Solar System and beyond, the search for planetary biosignatures of past or present extraterrestrial life, and the study of the Abiogenesis, origin and Protocell, early evolution of life on Earth. The field of astrobiology has its origins in the 20th century with the advent of space exploration and the discovery of exoplanets. Early astrobiology research focused on the search for extraterrestrial life and the study of the potential for life to exist on other pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snowball Earth
The Snowball Earth is a historical geology, geohistorical hypothesis that proposes that during one or more of Earth's greenhouse and icehouse Earth, icehouse climates, the planet's planetary surface, surface became nearly entirely freezing, frozen with no liquid oceanic or surface water exposed to the atmosphere of Earth, atmosphere. The most academically mentioned period of such a global ice age is believed to have occurred some time before 650 myr#Usage, mya during the Cryogenian period, which included at least two large glacial periods, the Sturtian glaciation, Sturtian and Marinoan glaciations. 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 global glaciation and the Geophysics, geophysical feasibility of an ice- or slush-cover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryogenian
The Cryogenian (from , meaning "cold" and , romanized: , meaning "birth") is a geologic period that lasted from . It is the second of the three periods of the Neoproterozoic era, preceded by the Tonian and followed by the Ediacaran. The Cryogenian was a time of drastic climate changes. After the long environmental stability/stagnation during the Boring Billion, the Sturtian glaciation began at the beginning of Cryogenian, freezing the entire planet in a state of severe icehouse climate known as a snowball Earth. After 70 million years it ended, but was quickly followed by another global ice age, the Marinoan glaciation. There is controversy over whether these glaciations indeed covered the entire planet, or whether a band of open sea survived near the equator (i.e. " slushball Earth"), but the extreme climates with massive expanse of ice sheets blocking off sunlight would nevertheless have significantly hindered primary production in the shallow seas and caused major mass ... [...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 2022 impact factor of 9.4. ''PNAS'' is the second most cited scientific journal, with more than 1.9 million cumulative citations from 2008 to 2018. In the past, ''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 available ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoproterozoic
The Neoproterozoic Era is the last of the three geologic eras of the Proterozoic geologic eon, eon, spanning from 1 billion to 538.8 million years ago, and is the last era of the Precambrian "supereon". It is preceded by the Mesoproterozoic era and succeeded by the Paleozoic era of the Phanerozoic eon, and is further subdivided into three geologic period, periods, the Tonian, Cryogenian and Ediacaran. One of the most severe glaciation events known in the geologic record occurred during the Cryogenian period of the Neoproterozoic, when global ice sheets may have reached the equator and created a "Snowball Earth" lasting about 100 million years. The earliest fossils of complex life are found in the Tonian period in the form of ''Otavia'', a primitive sponge, and the earliest fossil evidence of metazoan evolutionary radiation, radiation are found in the Ediacaran period, which included the namesaked Ediacaran biota as well as the oldest definitive cnidarians and bilaterians in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
