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John Day Formation
The John Day Formation is a series of rock strata exposed in the Picture Gorge district of the John Day River basin and elsewhere in north-central Oregon in the United States. The Picture Gorge exposure lies east of the Blue Mountain uplift, which cuts southwest–northeast through the Horse Heaven mining district northeast of Madras. Aside from the Picture Gorge district, which defines the type, the formation is visible on the surface in two other areas: another exposure is in the Warm Springs district west of the uplift, between it and the Cascade Range, and the third is along the south side of the Ochoco Mountains. All three exposures, consisting mainly of tuffaceous sediments and pyroclastic rock rich in silica, lie unconformably between the older rocks of the Clarno Formation below and Columbia River basalts above. Stratigraphy The strata, which vary in age from 39 million years to 18 million years, were formed mainly from ashfalls from volcanoes due to a series of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope Carbon-13, 13C in the atmosphere was exceptionally low in comparison with the more common isotope Carbon-12, 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Popigai impact structure, Siberia and in what is now ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Dioxide
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and most abundant families of materials, existing as a compound of several minerals and as a synthetic product. Notable examples include fused quartz, fumed silica, silica gel, opal and aerogels. It is used in structural materials, microelectronics (as an electrical insulator), and as components in the food and pharmaceutical industries. Structure In the majority of silicates, the silicon atom shows tetrahedral coordination, with four oxygen atoms surrounding a central Si atomsee 3-D Unit Cell. Thus, SiO2 forms 3-dimensional network solids in which each silicon atom is covalently bonded in a tetrahedral manner to 4 oxygen atoms. In contrast, CO2 is a linear molecule. The starkly different structures of the dioxid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apatotheria
Apatemyidae is an extinct family of placental mammals that took part in the first placental evolutionary radiation together with other early mammals such as the leptictids. Their relationships to other mammal groups are controversial; a 2010 study found them to be basal members of Euarchontoglires. Common in North America during the Paleocene, they are also represented in Europe by the genus '' Jepsenella''. Apatemyids in life Like most Paleocene mammals, the apatemyds were small and presumably insectivorous. Size ranged from that of a dormouse to a large rat. The toes were slender and well clawed, and the family were probably mainly arboreal. The skull was fairly massive compared to the otherwise slender skeleton, and the front teeth were long and hooked, resembling those of the modern aye-aye The aye-aye (''Daubentonia madagascariensis'') is a long-fingered lemur, a strepsirrhine primate native to Madagascar with rodent-like teeth that perpetually grow and a special thin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daeodon
''Daeodon'' is an extinct genus of entelodont even-toed ungulates that inhabited North America about 23 to 20 million years ago during the latest Oligocene and earliest Miocene. The type species is ''Daeodon shoshonensis'', described by a very questionable holotype by Cope. Some authors synonimize it with ''Dinohyus hollandi'' and several other species (see below), but due to the lack of diagnostic material, this is questionable at best. Another large member of this family, similar in size to ''Daeodon'', is the Asian ''Paraentelodon,'' but it is known by very incomplete material. Taxonomy The genus ''Daeodon'' was erected by the American anatomist and paleontologist Edward Drinker Cope in 1878. He classified it as a perissodactyl and thought that it was closely related to '' Menodus''. This classification persisted until the description of ''"Elotherium" calkinsi'' in 1905, a very similar and much more complete animal from the same rocks, which was promptly assigned as a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metasequoia
''Metasequoia'', or dawn redwoods, is a genus of fast-growing deciduous trees, one of three species of pinophyta, conifers known as redwoods. The living species ''Metasequoia glyptostroboides'' is native to Lichuan, Hubei, Lichuan county in Hubei province, China. Although the shortest of the Sequoioideae, redwoods, it grows to at least in height. Local villagers refer to the original tree from which most others derive as ''Shuǐshān'' (水杉）, or "water fir", which is part of a local shrine. Since its rediscovery in 1944, the dawn redwood has become a popular ornamental, with examples found in various parks in a variety of countries. Together with ''Sequoia sempervirens'' (coast redwood) and ''Sequoiadendron giganteum'' (giant sequoia) of California, ''Metasequoia'' is classified in the Cupressaceae subfamily Sequoioideae. ''M. glyptostroboides'' is the only living species in its genus, but three fossil species are known. Sequoioideae and several other genera have been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oreodont
Merycoidodontoidea, sometimes called "oreodonts" or "ruminating hogs", is an extinct superfamily of prehistoric cud-chewing artiodactyls with short faces and fang-like canine teeth. As their name implies, some of the better known forms were generally hog-like, and the group has traditionally been placed within the Suina (pigs, peccaries and their ancestors), though some recent work suggests they may have been more closely related to camels.Spaulding, M., O'Leary, M.A. & Gatesy, J. (2009): Relationships of Cetacea (Artiodactyla) Among Mammals: Increased Taxon Sampling Alters Interpretations of Key Fossils and Character Evolution. '' PLoS ONE'' no 4(9): e7062.article/ref> "Oreodont" means "mountain teeth", referring to the appearance of the molars. Most oreodonts were sheep-sized, though some genera grew to the size of cattle. They were heavy-bodied, with short four-toed hooves and comparatively long tails. The animals would have looked rather pig- or sheep-like, but features ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Day Fossil Beds National Monument
John Day Fossil Beds National Monument is a U.S. national monument in Wheeler and Grant counties in east-central Oregon. Located within the John Day River basin and managed by the National Park Service, the park is known for its well-preserved layers of fossil plants and mammals that lived in the region between the late Eocene, about 45 million years ago, and the late Miocene, about 5 million years ago. The monument consists of three geographically separate units: Sheep Rock, Painted Hills, and Clarno. The units cover a total of of semi-desert shrublands, riparian zones, and colorful badlands. About 210,000 people visited the park in 2016 to engage in outdoor recreation or to visit the Thomas Condon Paleontology Center or the James Cant Ranch Historic District. Before the arrival of Euro-Americans in the 19th century, the John Day basin was frequented by Sahaptin people who hunted, fished, and gathered roots and berries in the region. After road-building made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haystack Formation
Hay is grass, legumes, or other herbaceous plants that have been cut and dried to be stored for use as animal fodder, either for large grazing animals raised as livestock, such as cattle, horses, goats, and sheep, or for smaller domesticated animals such as rabbits and guinea pigs. Pigs can eat hay, but do not digest it as efficiently as herbivores do. Hay can be used as animal fodder when or where there is not enough pasture or rangeland on which to graze an animal, when grazing is not feasible due to weather (such as during the winter), or when lush pasture by itself would be too rich for the health of the animal. It is also fed when an animal is unable to access pasture—for example, when the animal is being kept in a stable or barn. Composition Commonly used plants for hay include mixtures of grasses such as ryegrass (''Lolium'' species), timothy, brome, fescue, Bermuda grass, orchard grass, and other species, depending on region. Hay may also include legumes, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kimberly Formation
Kimberly or Kimberley may refer to: Places and historical events Australia * Kimberley (Western Australia) ** Roman Catholic Diocese of Kimberley * Kimberley Warm Springs, Tasmania * Kimberley, Tasmania a small town * County of Kimberley, a cadastral unit in South Australia * Kimberley Marine Park, a marine protected area Canada * Kimberley, British Columbia, Canada New Zealand * Kimberley, New Zealand South Africa * Kimberley, Northern Cape, South Africa ** Siege of Kimberley (1899–1900), event during the Second Boer War United Kingdom * Kimberley, Norfolk * Kimberley, Nottinghamshire United States * Kimberly, Arkansas * Kimberly, Alabama, city * Kimberly Mansion, a historic house in Connecticut * Kimberly, Idaho, city * Kimberly, Minnesota * Kimberly Township, Aitkin County, Minnesota * Kimberly, Missouri, unincorporated community * Kimberly, Nevada, ghost town * Kimberly, Oregon, unincorporated community * Kimberly, Utah, abandoned town * Kimberly, Fayette Cou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picture Gorge Ignimbrite
An image is a visual representation of something. It can be two-dimensional, three-dimensional, or somehow otherwise feed into the visual system to convey information. An image can be an artifact, such as a photograph or other two-dimensional picture, that resembles a subject. In the context of signal processing, an image is a distributed amplitude of color(s). In optics, the term “image” may refer specifically to a 2D image. An image does not have to use the entire visual system to be a visual representation. A popular example of this is of a greyscale image, which uses the visual system's sensitivity to brightness across all wavelengths, without taking into account different colors. A black and white visual representation of something is still an image, even though it does not make full use of the visual system's capabilities. Images are typically still, but in some cases can be moving or animated. Characteristics Images may be two or three-dimensional, such as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
