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Microbially Induced Sedimentary Structure
Microbially induced sedimentary structures (MISS) are primary sedimentary structures formed by the interaction of microbes with sediment and physical agents of erosion, deposition, and transportation. The structures commonly form when microbial mats (which may comprise bacteria, fungi, protozoans, archaea or algae) are preserved in the sedimentary geological record. There are 17 main types of macroscopic and microscopic MISS.Noffke, N., 2010, Microbial Mats in Sandy Deposits from the Archean Era to Today: Springer Verlag, Heidelberg, 193 p. Of those, wrinkle structures and microbial mat chips are the most abundant in the fossil record. Other MISS include sinoidal structures, polygonal oscillation cracks, multidirected ripple marks, erosional remnants and pockets, or gas domes. Although these structures have only recently been named and systematically described, links between microbes and distinctive structures in sediments and sedimentary rocks have been suggested by several ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrobiology (journal)
''Astrobiology'' is a peer review, peer-reviewed scientific journal covering research on the abiogenesis, origin, evolution, distribution and future of life across the universe. The journal's scope includes astrobiology, astrophysics, astropaleontology, bioastronomy, cosmochemistry, ecogenomics, exobiology, extremophiles, geomicrobiology, gravitational biology, life detection technology, meteoritics, origins of life, planetary geoscience, planetary protection, prebiotic chemistry, space exploration technology and terraforming. Abstracting and indexing This journal is indexed by the following services: According to the ''Journal Citation Reports'', the journal has a 2019 impact factor of 4.091. References External links * Astrobiology journals Mary Ann Liebert academic journals Academic journals established in 2001 Bimonthly journals English-language journals {{astrobiology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curiosity (rover)
''Curiosity'' is a car-sized Mars rover Space exploration, exploring Gale (crater), Gale crater and Mount Sharp on Mars as part of NASA's Mars Science Laboratory (MSL) mission. ''Curiosity'' was launched from Cape Canaveral Space Force Station, Cape Canaveral (CCAFS) on November 26, 2011, at 15:02:00 Coordinated Universal Time, UTC and landed on Aeolis Palus inside Gale crater on Mars on August 6, 2012, 05:17:57 UTC. The Bradbury Landing site was less than from the center of the rover's touchdown target after a journey. Mission #Goals and objectives, goals include an investigation of the Martian climate of Mars, climate and geology of Mars, geology, an assessment of whether the selected field site inside Gale has ever offered environmental science, environmental conditions favorable for Life on Mars, microbial life (including investigation of the Water on Mars, role of water), and planetary habitability studies in preparation for Human mission to Mars, human exploration. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yellowknife Bay, Mars
Yellowknife Bay is a geologic formation in Gale Crater on the planet Mars. NASA's Mars Science Laboratory Rover (space exploration), rover, named Curiosity (rover), ''Curiosity'', arrived at the low lying depression on December 17, 2012, 125 Timekeeping on Mars, sols, or Martian days, into its 668-sol planned mission on the planet. Primary mission goals of the Mars Science Laboratory were to assess the potential habitability of the planet and whether or not the Martian environment is, or has ever been, capable of supporting life. The site was chosen after much study of the region by previous missions. The Mars Reconnaissance Orbiter observed morphological features created by the presence of Water on Mars, liquid water, suggesting the presence of an ancient lake which could have sustained Microorganism, microbial life. The geologic depression takes its name from the city Yellowknife, capital of the Canadian Northwest Territories, in honor of the 4 billion year old rock in the region ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars
Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmospheric pressure is a few thousandths of Earth's, atmospheric temperature ranges from and cosmic radiation is high. Mars retains some water, in the ground as well as thinly in the atmosphere, forming cirrus clouds, frost, larger polar regions of permafrost and ice caps (with seasonal snow), but no liquid surface water. Its surface gravity is roughly a third of Earth's or double that of the Moon. It is half as wide as Earth or twice the Moon, with a diameter of , and has a surface area the size of all the dry land of Earth. Fine dust is prevalent across the surface and the atmosphere, being picked up and spread at the low Martian gravity even by the weak wind of the tenuous atmosphere. The terrain of Mars roughly follows a north-south ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agronomic Revolution
The "Cambrian substrate revolution" or "Agronomic revolution", evidenced in trace fossils, is a sudden diversification of animal burrowing during the early Cambrian period. Before this "widening of the behavioural repertoire", bottom-dwelling animals mainly grazed on the microbial mats that lined the surface of the substrate, crawling above (like how freshwater snails still do) or burrowing just below them. These microbial mats created a barrier between the water and the sediment underneath, which was less water-logged than modern sea-floors, and almost completely anoxic (lacking in oxygen). As a result, the substrate was inhabited by sulfate-reducing bacteria, whose emissions of hydrogen sulfide (H2S) made the substrate toxic to most other organisms. Around the start of the Cambrian, organisms began to burrow vertically, forming a great diversity of different fossilisable burrow forms and traces as they penetrated the sediment for protection or to feed. These burrowing animals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ediacara Biota
The Ediacaran (; formerly Vendian) biota is a taxonomic period classification that consists of all life forms that were present on Earth during the Ediacaran Period (). These were enigmatic tubular and frond-shaped, mostly sessile, organisms. Trace fossils of these organisms have been found worldwide, and represent the earliest known complex multicellular organisms. The term "Ediacara biota" has received criticism from some scientists due to its alleged inconsistency, arbitrary exclusion of certain fossils, and inability to be precisely defined. The Ediacaran biota may have undergone evolutionary radiation in a proposed event called the Avalon explosion, . This was after the Earth had thawed from the Cryogenian period's extensive glaciation. This biota largely disappeared with the rapid increase in biodiversity known as the Cambrian explosion. Most of the currently existing body plans of animals first appeared in the fossil record of the Cambrian rather than the Ediacara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ediacaran
The Ediacaran ( ) is a geological period of the Neoproterozoic geologic era, Era that spans 96 million years from the end of the Cryogenian Period at 635 Million years ago, Mya to the beginning of the Cambrian Period at 538.8 Mya. It is the last period of the Proterozoic geologic eon, Eon as well as the last of the so-called "Precambrian supereon", before the beginning of the subsequent Cambrian Period marks the start of the Phanerozoic Eon, where recognizable fossil evidence of life becomes common. The Ediacaran Period is named after the Ediacara Hills of South Australia, where trace fossils of a diverse community of previously unrecognized lifeforms (later named the Ediacaran biota) were first discovered by geologist Reg Sprigg in 1946. Its status as an official geological period was ratified in 2004 by the International Union of Geological Sciences (IUGS), making it the first new geological period declared in 120 years. Although the period took namesake from the Ediacara Hills ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all of Earth's water is contained in its global ocean, covering Water distribution on Earth, 70.8% of Earth's crust. The remaining 29.2% of Earth's crust is land, most of which is located in the form of continental landmasses within Earth's land hemisphere. Most of Earth's land is at least somewhat humid and covered by vegetation, while large Ice sheet, sheets of ice at Polar regions of Earth, Earth's polar polar desert, deserts retain more water than Earth's groundwater, lakes, rivers, and Water vapor#In Earth's atmosphere, atmospheric water combined. Earth's crust consists of slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's outer core, Earth has a liquid outer core that generates a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossils
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Though the fossil record is incomplete, numerous studies have demonstrated that there is enough information available to give a good understanding of the pattern of diversification of life on Earth. In addition, the record can predict and fill gaps such as the discovery of '' Tiktaalik'' in the arctic of Canada. Paleontology includes the study of fossils: their age, method of formation, and evolutionary significance. Specimens are sometimes considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years to 4.1 billion years old. Early edition, published online before print. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AP News
The Associated Press (AP) is an American not-for-profit news agency headquartered in New York City. Founded in 1846, it operates as a cooperative, unincorporated association, and produces news reports that are distributed to its members, major U.S. daily newspapers and radio and television broadcasters. Since the award was established in 1917, the AP has earned 59 Pulitzer Prizes, including 36 for photography. The AP is also known for its widely used '' AP Stylebook'', its AP polls tracking NCAA sports, sponsoring the National Football League's annual awards, and its election polls and results during US elections. By 2016, news collected by the AP was published and republished by more than 1,300 newspapers and broadcasters. The AP operates 235 news bureaus in 94 countries, and publishes in English, Spanish, and Arabic. It also operates the AP Radio Network, which provides twice hourly newscasts and daily sportscasts for broadcast and satellite radio and television station ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedimentary Structures
Sedimentary structures include all kinds of features in sediments and sedimentary rocks, formed at the time of deposition. Sediments and sedimentary rocks are characterized by bedding, which occurs when layers of sediment, with different particle sizes are deposited on top of each other. These beds range from millimeters to centimeters thick and can even go to meters or multiple meters thick. Sedimentary structures such as cross-bedding, graded bedding, and ripple marks are utilized in stratigraphic studies. They help indicate the original position of strata in geologically complex terrains. They also provide insight into the depositional environment of the sediment. Flow structures There are two kinds of flow structures: bidirectional (multiple directions, back-and-forth) and unidirectional. Flow regimes in single-direction (typically fluvial) flow, which at varying speeds and velocities produce different structures, are called bedforms. In the ''lower flow regime'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
