|
Acraman Impact Structure
Acraman impact structure 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 impact structure and independent discovery of its ejecta were first reported in the journal ''Science'' in 1986 by George E. Williams and Victor A. Gostin. The evidence for impact includes the presence of shatter cones and shocked quartz in shattered bedrock on islands within Lake Acraman. The impact structure 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 million 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 c ... [...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] |
Department Of Environment, Water And Natural Resources
The Department for Environment and Water (DEW) is a department of the Government of South Australia. It is responsible for ensuring that the state of South Australia's natural resources are managed productively and sustainably, while improving the condition and resilience of the state's natural environment. The current department was created on 1 July 2012 by the merger of the Department of Environment and Natural Resources and the Department for Water as the Department of Environment, Water and Natural Resources (DEWNR), it was given its present name on 22 March 2018. History of the environment portfolio On 23 December 1971, a new department called the ''Department of Environment and Conservation'' was created by the amalgamation of the ''Museum Department'' and the ''State Planning Office'' which was part of the ''Department of the Premier and of Development''. On 18 December 1975, the ''Department of Environment and Conservation'' was renamed as the ''Department for the En ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precambrian Australia
The Precambrian ( ; or pre-Cambrian, sometimes abbreviated pC, 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 Latinized 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proterozoic Impact Craters
The Proterozoic ( ) is the third of the four geologic eons of Earth's history, spanning the time interval from 2500 to 538.8 Mya, and is the longest eon of Earth's geologic time scale. It is preceded by the Archean and followed by the Phanerozoic, and is the most recent part of the Precambrian "supereon". The Proterozoic is subdivided into three geologic eras (from oldest to youngest): the Paleoproterozoic, Mesoproterozoic and Neoproterozoic. It covers the time from the appearance of free oxygen in Earth's atmosphere to just before the proliferation of complex life on the Earth during the Cambrian Explosion. The name ''Proterozoic'' combines two words of Greek origin: meaning "former, earlier", and , meaning "of life". Well-identified events of this eon were the transition to an oxygenated atmosphere during the Paleoproterozoic; the evolution of eukaryotes via symbiogenesis; several global glaciations, which produced the 300 million years-long Huronian glaciation (during ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Craters Of South Australia
Impact may refer to: * Impact (mechanics), a large force or mechanical shock over a short period of time * 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 * Impact wrench, a socket wrench power tool capable of high torque 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 s ... [...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, "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. 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) aimed at developers and, unlike the old .NET ver ... [...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 he 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 e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acraman Creek
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 John Acraman (1829 – 22 June 1907) was a prominent businessman in the colony of South Australia, and he has a place in the history of Australian football in that state. History John Acraman was born in England, a son of William Edward Acrama ... (1829–1907), * Rodney Acraman, Fiji Islander {{disambiguation, surname ... [...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] |
Acritarch
Acritarchs () are organic microfossils, known from the Precambrian 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. Many acritarchs likely represent resting cysts of single-celled marine phytoplanktonic algae, similar to those produced by living dinoflagellates. 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 alga ... [...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] |
