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Fishtail Projectile Point
Fishtail points, also known as Fell points are a style of Paleoindian projectile point widespread in South America at the end of the Late Pleistocene. Their chronological timing is disputed, with some authors favouring a short chronology spanning 12,800–12,200 years Before Present Before Present (BP) years, or "years before present", is a time scale used mainly in archaeology, geology and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Becaus ... (BP), while others favouring a long chronology spanning 13,500–10,200 years BP. It is the earliest widespread lithic style in South America, being contemporaneous in its earlier stages to the use of Clovis points in North America. Fishtail points may be derived from Clovis points, or possibly from Fishtail-like points found on the Gulf Coast of North America and in Central America. The name "Fishtail point" derives from their fish-like shape, with bro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andes
The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S latitude), and has an average height of about . The Andes extend from north to south through seven South American countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina. Along their length, the Andes are split into several ranges, separated by intermediate depressions. The Andes are the location of several high plateaus—some of which host major cities such as Quito, Bogotá, Cali, Arequipa, Medellín, Bucaramanga, Sucre, Mérida, El Alto and La Paz. The Altiplano plateau is the world's second-highest after the Tibetan plateau. These ranges are in turn grouped into three major divisions based on climate: the Tropical Andes, the Dry Andes, and the Wet Andes. The Andes Mountains are the highest m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clovis Culture
The Clovis culture is a prehistoric Paleoamerican culture, named for distinct stone and bone tools found in close association with Pleistocene fauna, particularly two mammoths, at Blackwater Locality No. 1 near Clovis, New Mexico, in 1936 and 1937 (though Paleoindian artifacts had been found at the site since the 1920s). It appears around 11,500–11,000 uncalibrated years before present (YBP)"Clovis Culture" entry in the ''Concise Oxford Dictionary of Archaeology'': "9,500–9,000 BC". at the end of the last glacial period and is characterized by the manufacture of " Clovis points" and distinctive bone and ivory tools. Archaeologists' most precise determinations at present suggest this radiocarbon age is equal to roughly 13,200 to 12,900 calendar years ago. The only human burial that has been directly associated with tools from the Clovis culture included the remains of an infant boy researchers named Anzick-1. Paleogenetic analyses of Anzick-1's ancient nuclear, mitoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at . Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold. There are many different varieties of quartz, several of which are classified as gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. Quartz is the mineral defining the val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opal
Opal is a hydrated amorphous form of silica (SiO2·''n''H2O); its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Due to its amorphous property, it is classified as a mineraloid, unlike crystalline forms of silica, which are considered minerals. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most commonly found with limonite, sandstone, rhyolite, marl, and basalt. The name ''opal'' is believed to be derived from the Sanskrit word (), which means 'jewel', and later the Greek derivative (), which means 'to see a change in color'. There are two broad classes of opal: precious and common. Precious opal displays play-of-color ( iridescence); common opal does not. Play-of-color is defined as "a pseudo chromatic optical effect resulting in flashes of colored light from certain minerals, as they are turned in white light." The internal structure of precious opal causes it to di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartzite
Quartzite is a hard, non- foliated metamorphic rock which was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to grey, though quartzites often occur in various shades of pink and red due to varying amounts of hematite. Other colors, such as yellow, green, blue and orange, are due to other minerals. The term ''quartzite'' is also sometimes used for very hard but unmetamorphosed sandstones that are composed of quartz grains thoroughly cemented with additional quartz. Such sedimentary rock has come to be described as orthoquartzite to distinguish it from metamorphic quartzite, which is sometimes called metaquartzite to emphasize its metamorphic origins. Quartzite is very resistant to chemical weathering and often forms ridges and resistant hilltops. The nearly pure silica conte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jasper
Jasper, an aggregate of microgranular quartz and/or cryptocrystalline chalcedony and other mineral phases,Kostov, R. I. 2010. Review on the mineralogical systematics of jasper and related rocks. – Archaeometry Workshop, 7, 3, 209-213PDF/ref> is an opaque, impure variety of silica, usually red, yellow, brown or green in color; and rarely blue. The common red color is due to iron(III) inclusions. Jasper breaks with a smooth surface and is used for ornamentation or as a gemstone. It can be highly polished and is used for items such as vases, seals, and snuff boxes. The specific gravity of jasper is typically 2.5 to 2.9. Jaspillite is a banded-iron-formation rock that often has distinctive bands of jasper. Etymology and history The name means "spotted or speckled stone," and is derived via Old French ''jaspre'' (variant of Anglo-Norman ''jaspe'') and Latin ''iaspidem'' (nom. ''iaspis'') from Greek ἴασπις ''iaspis'' (feminine noun), from an Afroasiatic language (cf. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chert
Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a precipitation (chemistry), chemical precipitate or a diagenesis, diagenetic replacement, as in petrified wood. Chert is typically composed of the petrified remains of siliceous ooze, the biogenic sediment that covers large areas of the deep ocean floor, and which contains the silicon skeletal remains of diatoms, Dictyochales, silicoflagellates, and radiolarians. Precambrian cherts are notable for the presence of fossil cyanobacteria. In addition to Micropaleontology, microfossils, chert occasionally contains macrofossils. However, some chert is devoid of any fossils. Chert varies greatly in color (from white to black), but most often manifests as gray, brown, grayish brown and light green to rusty redW.L. Roberts, T.J. Campbell, G.R. Rapp Jr. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silcrete
Silcrete is an indurated (resists crumbling or powdering) soil duricrust formed when surface soil, sand, and gravel are cemented by dissolved silica. The formation of silcrete is similar to that of calcrete, formed by calcium carbonate, and ferricrete, formed by iron oxide. It is a hard and resistant material, and though different in origin and nature, appears similar to quartzite. As a duricrust, there is potential for preservation of root structures as trace fossils. Silcrete is common in the arid regions of Australia and Africa often forming the resistant cap rock on features such as the ''breakaways'' of the Stuart Range of South Australia. Silcrete can be found at a lesser extent throughout the world especially England (e.g. '' Hertfordshire puddingstone''), and France. In the Great Plains of the United States, polished silcrete cobbles are locally common on the surface and in river gravels east of the outcrops of the Ogallala Formation. In Australia, silcrete was widely use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tierra Del Fuego
Tierra del Fuego (, ; Spanish for "Land of the Fire", rarely also Fireland in English) is an archipelago off the southernmost tip of the South American mainland, across the Strait of Magellan. The archipelago consists of the main island, Isla Grande de Tierra del Fuego, with an area of , and a group of many islands, including Cape Horn and Diego Ramírez Islands. Tierra del Fuego is divided between Chile and Argentina, with the latter controlling the eastern half of the main island and the former the western half plus the islands south of Beagle Channel and the southernmost islands. The southernmost extent of the archipelago is just north of latitude 56°S. The earliest known human settlement in Tierra del Fuego dates to approximately 8,000 BC. Europeans first explored the islands during Ferdinand Magellan's expedition of 1520. ''Tierra del Fuego'' and similar namings stem from sightings of the many bonfires that the natives built. Settlement by those of European descent and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bahia
Bahia ( , , ; meaning "bay") is one of the 26 Federative units of Brazil, states of Brazil, located in the Northeast Region, Brazil, Northeast Region of the country. It is the fourth-largest Brazilian state by population (after São Paulo (state), São Paulo, Minas Gerais, and Rio de Janeiro (state), Rio de Janeiro) and the 5th-largest by area. Bahia's capital is the city of Salvador, Bahia, Salvador (formerly known as "Cidade do São Salvador da Bahia de Todos os Santos", literally "City of the Saint Savior of the Bay of All the Saints"), on a Spit (landform), spit of land separating the Bay of All Saints from the Atlantic. Once a monarchial stronghold dominated by Agriculture in Brazil, agricultural, Slavery in Brazil, slaving, and ranching interests, Bahia is now a predominantly Working class, working-class industrial and agricultural state. The state is home to 7% of the Brazilian population and produces 4.2% of the country's GDP. Name The name of the state derives from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amazonas (Brazilian State)
Amazonas () is a state of Brazil, located in the North Region in the northwestern corner of the country. It is the largest Brazilian state by area and the 9th largest country subdivision in the world, and the largest in South America, being greater than the areas of Uruguay, Paraguay, and Chile combined. Mostly located in the Southern Hemisphere, it is the third largest country subdivision in the Southern Hemisphere after the Australian states of Western Australia and Queensland. Entirely in the Western Hemisphere, it is the fourth largest in the Western Hemisphere after Greenland, Nunavut and Alaska. It would be the sixteenth largest country in land area, slightly larger than Mongolia. Neighbouring states are (from the north clockwise) Roraima, Pará, Mato Grosso, Rondônia, and Acre. It also borders the nations of Peru, Colombia and Venezuela. This includes the Departments of Amazonas, Vaupés and Guainía in Colombia, as well as the Amazonas state in Venezuela, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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