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Acraman Crater
Acraman crater is a deeply eroded impact crater in the Gawler Ranges of South Australia. Its location is marked by Lake Acraman, a circular ephemeral playa lake about in diameter. The discovery of the crater and independent discovery of its ejecta were first reported in the journal Science in 1986. The evidence for impact includes the presence of shatter cones and shocked quartz in shattered bedrock on islands within Lake Acraman. The crater is deeply eroded, and its original size must be inferred by indirect means. Some authors estimate an original diameter of up to , while other suggest a smaller size, perhaps only , closer to that of the depression in which Lake Acraman is centred. The larger size estimate would imply an energy release of 5.2 × 106 megatons of TNT. The impact event is estimated to have occurred about 590 million years ago during the Ediacaran; this age is not derived from the crater itself but from the position of ejecta within nearby sedimentary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Gairdner
Lake Gairdner is a large endorheic salt lake in the Australian state of South Australia, to the north of the Eyre Peninsula. When in flood, the lake is considered the third largest salt lake in Australia. Description Lake Gairdner is located about northwest of the state capital of Adelaide and about northwest of Port Augusta in the foothills on the northern side of the Gawler Ranges and to the west of Lake Torrens. The lake is over long and across with salt over thick in some places. Lake Gairdner was named by the Governor of South Australia, Richard MacDonnell in October 1857 after Gordon Gairdner, a Chief Clerk of the Australian Department in the Colonial Office. Lake Gairdner along with Lake Everard and Lake Harris form the extent of the Lake Gairdner National Park. The lakes were all once part of an inland sea that stretched all the way to the Gulf of Carpentaria. Six ephemeral creeks feed the lake including Garden Well Creek, Gorge Creek and Yeltabinna Creek. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flinders Ranges
The Flinders Ranges are the largest mountain range in South Australia, which starts about north of Adelaide. The ranges stretch for over from Port Pirie to Lake Callabonna. The Adnyamathanha people are the Aboriginal group who have inhabited the range for tens of thousands of years. Its most well-known landmark is Wilpena Pound / Ikara, a formation that creates a natural amphitheatre covering and containing the range's highest peak, St Mary Peak (). The ranges include several national parks, the largest being the Ikara-Flinders Ranges National Park, as well as other protected areas. It is an area of great geological and palaeontological significance, and includes the oldest fossil evidence of animal life was discovered. The Ediacaran Period and Ediacaran biota take their name from the Ediacara Hills within the ranges. In August 2022, a nomination for the Flinders Ranges to be named a World Heritage Site was lodged. History The first humans to inhabit the Flinders ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precambrian Australia
The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time. The Precambrian is an informal unit of geologic time, subdivided into three eons (Hadean, Archean, Proterozoic) of the geologic time scale. It spans from the formation of Earth about 4.6 billion years ago ( Ga) to the beginning of the Cambrian Period, about million years ago ( Ma), when hard-shelled creatures first appeared in abundance. Overview Relatively little is known about the Precambrian, despite it making up roughly seven-eighths of the Earth's history, and what is known has largely been discovered from the 1960s onwards. The Precambrian fossil r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proterozoic Impact Craters
The Proterozoic () is a geological eon spanning the time interval from 2500 to 538.8million years ago. It is the most recent part of the Precambrian "supereon". It is also the longest eon of the Earth's geologic time scale, and it is subdivided into three geologic eras (from oldest to youngest): the Paleoproterozoic, Mesoproterozoic, and Neoproterozoic. The Proterozoic covers the time from the appearance of oxygen in Earth's atmosphere to just before the proliferation of complex life (such as trilobites or corals) on the Earth. The name ''Proterozoic'' combines two forms of ultimately Greek origin: meaning 'former, earlier', and , 'of life'. The well-identified events of this eon were the transition to an oxygenated atmosphere during the Paleoproterozoic; the evolution of eukaryotes; several glaciations, which produced the hypothesized Snowball Earth during the Cryogenian Period in the late Neoproterozoic Era; and the Ediacaran Period (635 to 538.8 Ma) which is chara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Craters Of South Australia
Impact may refer to: * Impact (mechanics), a high force or shock (mechanics) over a short time period * Impact, Texas, a town in Taylor County, Texas, US Science and technology * Impact crater, a meteor crater caused by an impact event * Impact event, the collision of a meteoroid, asteroid or comet with Earth * Impact factor, a measure of the citations to a science or social science journal Books and magazines * ''Impact'' (novel), a 2010 novel by Douglas Preston *''Impact Press'', a former Orlando, Florida-based magazine * Impact Magazines, a former UK magazine publisher * ''Impact'' (conservative magazine), a British political magazine * ''Impact'' (British magazine), a British action film magazine * ''Impact'', a French action film magazine spun off from ''Mad Movies'' * ''Impact'' (UNESCO magazine), a former UNESCO quarterly titled ''IMPACT of science on society'' * ''Impact'' (student magazine), a student magazine for the University of Nottingham, England * '' Bathi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA World Wind
NASA WorldWind is an open-source (released under the NOSA license and the Apache 2.0 license) virtual globe. According to the website (https://worldwind.arc.nasa.gov/), "WorldWind is an open source virtual globe API. WorldWind allows developers to quickly and easily create interactive visualizations of 3D globe, map and geographical information. Organizations around the world use WorldWind to monitor weather patterns, visualize cities and terrain, track vehicle movement, analyze geospatial data and educate humanity about the Earth." It was first developed by NASA in 2003 for use on personal computers and then further developed in concert with the open source community since 2004. As of 2017, a web-based version of WorldWind is available online. An Android version is also available. The original version relied on .NET Framework, which ran only on Microsoft Windows. The more recent Java version, WorldWind Java, is cross platform, a software development kit (SDK) a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Acraman
John Acraman (1829 – 22 June 1907) was a prominent businessman in the colony of South Australia, and has a place in the history of Australian football in that State. History John Acraman was born in England, a son of William Edward Acraman (c. 1800 – 27 November 1875) and Mary Acraman (c. 1801 – 9 February 1871) of Sidmouth, Devon, England. Theirs was an old and honorable Somersetshire family, whose surname was formerly spelled Akerman, or Ackerman. John's grandfather Daniel Wade Acraman, a Bristol businessman, was a noted connoisseur of art. This article gives father William Edward Acraman's life span as 1790–1875 John Acraman's early days were spent at Bath, Somerset and Clifton, Bristol, and he was educated in both places. His father was a wealthy merchant and industrialist, owner of several East India ships. At Bristol he was nominally apprenticed to his father, in order that he might qualify for membership of the prestigious Society of Merchant Venturers. His elde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acraman Creek , Fiji Islander
{{disambiguation, surname ...
Acraman may refer to: Places *Acraman crater, an impact crater in South Australia ** Lake Acraman, a lake at the centre of the Acraman crater * Acraman Creek, a stream in the west of South Australia **Acraman Creek Conservation Park, a protected area in the west of South Australia People with the surname *John Acraman (1829–1907), *Rodney Acraman Rodney Acraman was Fiji's Acting Ombudsman and thus the ''ex officio'' Chairperson of the Fiji Human Rights Commission from 2006 to 2007, when he was replaced by Shaista Shameem. The Military administration, which took power in a coup d'état on 5 ... [...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 composed of 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 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 Ediacaran. For macroorganisms, the Cambrian biota appears to have almost completely replaced the organisms that dominated the Ediacaran fossil record, although relationships are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acritarch
Acritarchs are organic microfossils, known from approximately 1800 million years ago to the present. The classification is a catch all term used to refer to any organic microfossils that cannot be assigned to other groups. Their diversity reflects major ecological events such as the appearance of predation and the Cambrian explosion. Definition Acritarchs were originally defined as non- acid soluble (i.e. non-carbonate, non-siliceous) organic-walled microfossils consisting of a central cavity, and whose biological affinities cannot be determined with certainty. Most commonly they are composed of thermally altered acid insoluble carbon compounds ( kerogen). Acritarchs may include the remains of a wide range of quite different kinds of organisms—ranging from the egg cases of small metazoans to resting cysts of many kinds of chlorophyta (green algae). It is likely that most acritarch species from the Paleozoic represent various stages of the life cycle of algae that were ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptive Radiation
In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, alters biotic interactions or opens new environmental niches. Starting with a single ancestor, this process results in the speciation and phenotypic adaptation of an array of species exhibiting different morphological and physiological traits. The prototypical example of adaptive radiation is finch speciation on the Galapagos ("Darwin's finches"), but examples are known from around the world. Characteristics Four features can be used to identify an adaptive radiation: #A common ancestry of component species: specifically a ''recent'' ancestry. Note that this is not the same as a monophyly in which ''all'' descendants of a common ancestor are included. #A phenotype-environment correlation: a ''significant'' association between environments and the mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iridium Anomaly
The term iridium anomaly commonly refers to an unusual abundance of the chemical element iridium in a layer of rock strata at the Cretaceous–Paleogene (K–Pg) boundary. The unusually high concentration of a rare metal like iridium is often taken as evidence for an extraterrestrial impact event. Anomaly characteristics The type locality of this iridium anomaly is near Raton, New Mexico. Iridium is a very rare element in the Earth's crust, but is found in anomalously high concentrations (around 100 times greater than normal) in a thin worldwide layer of clay marking the boundary between the Cretaceous and Paleogene periods, 66 million years ago. This boundary is marked by a major extinction event, including that of the dinosaurs along with about 70% of all other species. The clay layer also contains small grains of shocked quartz and, in some places, small weathered glass beads thought to be tektites. Meteorite impact theory A team consisting of the physicist Luis Alvarez, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
