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Mesoproterozoic Orogenies
The Mesoproterozoic Era is a geologic era that occurred from . The Mesoproterozoic was the first era of Earth's history for which a fairly definitive geological record survives. Continents existed during the preceding era (the Paleoproterozoic), but little is known about them. The continental masses of the Mesoproterozoic were more or less the same ones that exist today, although their arrangement on the Earth's surface was different. Major events and characteristics The major events of this era are the breakup of the Columbia supercontinent, the formation of the Rodinia supercontinent, and the evolution of sexual reproduction. This era is marked by the further development of continental plates and plate tectonics. The supercontinent of Columbia broke up between 1500 and 1350 million years ago, and the fragments reassembled into the supercontinent of Rodinia around 1100 to 900 million years ago, on the time boundary between the Mesoproterozoic and the subsequent Neoproterozoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrite
The mineral pyrite ( ), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of ''fool's gold''. The color has also led to the nicknames ''brass'', ''brazzle'', and ''brazil'', primarily used to refer to pyrite found in coal. The name ''pyrite'' is derived from the Greek (), 'stone or mineral which strikes fire', in turn from (), 'fire'. In ancient Roman times, this name was applied to several types of stone that would create sparks when struck against steel; Pliny the Elder described one of them as being brassy, almost certainly a reference to what is now called pyrite. By Georgius Agricola's time, , the term had become a generic term for all of the sulfide minerals. Pyrite is usually found associated with other sulfides or oxides in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Ruker Orogeny
The Late Ruker orogeny, also known as the Nimrod orogeny, was a mountain building event around 1 billion years ago in the Proterozoic. Large portions of West Antarctica were added to the continent during this event. The orogeny was marked by subsidence, sedimentation and underwater volcanic eruptions along the proto-Pacific Ocean margin of proto-Antarctica. This melted some older igneous plutonic rocks and metamorphic rocks and caused some new metamorphism. Red beds were deposited and are now preserved in the Ritscher Upland of Queen Maud Land. Stromatolite carbonate beds and quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ... arenite in the Shackleton Range serves as evidence for a stable platform and epicratonic sea during the period. See also * List of orogenies * Geol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Union Of Geological Sciences
The International Union of Geological Sciences (IUGS) is an international non-governmental organization devoted to global cooperation in the field of geology. As of 2023, it represents more than 1 million geoscientists around the world. About Founded in 1961, the IUGS was established to maintain collaboration between the International Geological Congresses, which have taken place every four years since 1875. It is a Scientific Union member of the International Science Council (ISC), formerly the International Council for Science (ICSU), which it recognizes as the co-ordinating body for the international organization of science. Currently, geologists from 121 countries (and regions) are represented in the IUGS. A broad range of scientific topics is covered by its commission, task groups, joint programmes and affiliated organizations. IUGS promotes and encourages the study of geological problems, especially those of worldwide significance, and supports and facilitates international ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chronometry
Chronometry or horology () is the science studying the measurement of time and timekeeping. Chronometry enables the establishment of standard measurements of time, which have applications in a broad range of social and scientific areas. ''Horology'' usually refers specifically to the study of mechanical timekeeping devices, while ''chronometry'' is broader in scope, also including biological behaviours with respect to time (biochronometry), as well as the dating of geological material (geochronometry). Horology is commonly used specifically with reference to the mechanical instruments created to keep time: clocks, watches, clockwork, sundials, hourglasses, clepsydras, timers, time recorders, marine chronometers, and atomic clocks are all examples of instruments used to measure time. People interested in horology are called ''horologists''. That term is used both by people who deal professionally with timekeeping apparatuses, as well as enthusiasts and scholars of horology. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphy
Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostratigraphy (lithologic stratigraphy), biostratigraphy (biologic stratigraphy), and chronostratigraphy (stratigraphy by age). Historical development Catholic priest Nicholas Steno established the theoretical basis for stratigraphy when he introduced the law of superposition, the principle of original horizontality and the principle of lateral continuity in a 1669 work on the fossilization of organic remains in layers of sediment. The first practical large-scale application of stratigraphy was by William Smith in the 1790s and early 19th century. Known as the "Father of English geology", Smith recognized the significance of strata or rock layering and the importance of fossil markers for correlating strata; he created the first geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stenian
The Stenian Period ( , from , meaning "narrow") is the final geologic period in the Mesoproterozoic Era and lasted from Mya to Mya (million years ago). Instead of being based on stratigraphy, these dates are defined chronometrically. The name derives from narrow polymetamorphic belts formed over this period. It is preceded by the Ectasian Period and followed by the Neoproterozoic era and the Tonian period. The supercontinent Rodinia assembled during the Stenian. It would last into the Tonian period before breaking up in the 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 Cryoge .... This period includes the formation of the Keweenawan Rift at about 1100 Mya. Fossils of the oldest known sexually reproducing organism, '' Bangiomorpha pubescens'', first appeared in the Sten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectasian
The Ectasian Period (from , meaning "extension") is the second geologic period in the Mesoproterozoic Era and lasted from Mya to Mya (million years ago). Instead of being based on stratigraphy, these dates are defined chronometrically. Geologically the name refers to the continued expansion of platform covers during this period. In the early Ectasian period, a day was 17 hours and 32 minutes. At the end of the Ectasian, it was 18 hours and 28 minutes. This period is interesting for the first evidence of sexual reproduction. The 1.2-billion-year-old Hunting Formation on Somerset Island, Canada, dates from the end of the Ectasian. It contains the microfossils of the multicellular filaments of '' Bangiomorpha pubescens'' (type of red algae), the first taxonomically resolved eukaryote. This was the first organism that exhibited sexual reproduction, which is an essential feature for complex multicellularity. Complex multicellularity is different from "simple" multicellularity, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calymmian
The Calymmian Period (from , meaning "cover") is the first geologic period in the Mesoproterozoic Era and lasted from Mya to Mya (million years ago). Instead of being based on stratigraphy, these dates are defined chronometrically. The period is characterised by expansion of existing platform covers, or by new platforms on recently cratonized basements. The supercontinent In geology, a supercontinent is the assembly of most or all of Earth's continent, continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", ... Columbia started to break up during the Calymmian some 1500 Mya. The Volyn biota have been dated to 1500 Mya. See also * * References * * Mesoproterozoic Geological periods Proterozoic geochronology {{geochronology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stromatolites
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. This process generates the characteristic 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 life. As of the Holocene, living forms are rare. Definition Stromatolites are layered, biochemical, accretionary structur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multicellular Organisms
A multicellular organism is an organism that consists of more than one cell, unlike unicellular organisms. All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- and partially multicellular, like slime molds and social amoebae such as the genus ''Dictyostelium''. Multicellular organisms arise in various ways, for example by cell division or by aggregation of many single cells. Colonial organisms are the result of many identical individuals joining together to form a colony. However, it can often be hard to separate colonial protists from true multicellular organisms, because the two concepts are not distinct; colonial protists have been dubbed "pluricellular" rather than "multicellular". There are also macroscopic organisms that are multinucleate though technically unicellular, such as the Xenophyophorea that can reach 20 cm. Evolutionary history Occurrence Multicellularity has evolved indepen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grenville Orogeny
The Grenville orogeny was a long-lived Mesoproterozoic mountain-building event associated with the assembly of the supercontinent Rodinia. Its record is a prominent orogenic belt which spans a significant portion of the North American continent, from Labrador to Mexico, as well as to Scotland. Grenville orogenic crust of mid-late Mesoproterozoic age (1250980 Ma) is found worldwide, but generally only events which occurred on the southern and eastern margins of Laurentia are recognized under the "Grenville" name. These orogenic events are also known as the Kibaran orogeny in Africa, the Dalslandian orogeny in Western Europe, and the Sunsás orogeny in Brazil. Timescale The problem of timing the Grenville orogeny is an area of some contention. The timescale outlined by Toby Rivers in 2002 is derived from the well-preserved Grenville Province and represents one of the most detailed records of the orogeny. This classification considers the classical Grenville designation to cover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picuris Orogeny
The Picuris orogeny was an orogenic event in what is now the Southwestern United States from 1.43 to 1.3 billion years ago in the Calymmian Period of the Mesoproterozoic. The event is named for the Picuris Mountains in northern New Mexico and interpreted either as the suturing of the Granite-Rhyolite crustal province to the southern margin of the proto-North American continent Laurentia or as the final suturing of the Mazatzal crustal province onto Laurentia. According to the former hypothesis, this was the second in a series of orogenies within a long-lived convergent boundary along southern Laurentia that ended with the ca. 1200–1000 Mya Grenville orogeny during the final assembly of the supercontinent Rodinia, which ended an 800-million-year episode of convergent boundary tectonism. Description Age and isotope data show that southern North America is composed of a series of northeast-trending provinces representing island arc terranes accreted onto the 1800 Mya core of La ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
