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Bluestone
Bluestone is a cultural or commercial name for a number of natural dimension stone, dimension or building stone varieties, including: * basalt in Victoria (Australia), Victoria, Australia, and in New Zealand * diabase, dolerites in Tasmania, Australia; and in Britain (including Stonehenge) * feldspar, feldspathic sandstone in the US and Canada * limestone in the Shenandoah Valley in the US, from the Hainaut (province), Hainaut quarries in Soignies, Belgium, and from quarries in County Carlow, County Galway and County Kilkenny in Ireland * slate in South Australia It is unrelated to human-made blue brick. Stonehenge The term "bluestone" in Britain is used in a loose sense to cover all of the "foreign", not intrinsic, stones and rock debris at Stonehenge. It is a "convenience" label rather than a geological term, since at least 46 different rock types are represented. One of the most common rocks in the assemblage is known as Preseli spotted dolerite—a chemically altered i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stonehenge
Stonehenge is a prehistoric Megalith, megalithic structure on Salisbury Plain in Wiltshire, England, west of Amesbury. It consists of an outer ring of vertical sarsen standing stones, each around high, wide, and weighing around 25 tons, topped by connecting horizontal lintel stones, held in place with mortise and tenon joints, a feature unique among contemporary monuments. Inside is a ring of smaller bluestones. Inside these are free-standing trilithons, two bulkier vertical sarsens joined by one lintel. The whole monument, now ruinous, is aligned towards the sunrise on the summer solstice and sunset on the winter solstice. The stones are set within Earthwork (archaeology), earthworks in the middle of the densest complex of Neolithic British Isles, Neolithic and Bronze Age Britain, Bronze Age monuments in England, including several hundred ''tumuli'' (burial mounds). Stonehenge was constructed in several phases beginning about 3100 BC and continuing until about 1600 B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preseli Hills
The Preseli Mountains (, ; or ), also known as the Preseli Hills, or just the Preselis, are a range of hills in western Wales, mostly within the Pembrokeshire Coast National Park and entirely within the county of Pembrokeshire. The range stretches from the proximity of Newport in the west to Crymych in the east, some in extent. The highest point at above sea level is Foel Cwmcerwyn. The ancient of track along the top of the range is known as the Golden Road. The Preselis have a diverse ecosystem, many prehistoric sites, and are a popular tourist destination. There are scattered settlements and small villages; the uplands provide extensive unenclosed grazing, and the lower slopes are mainly enclosed pasture. Slate quarrying was once an important industry. More recently, igneous rock is being extracted. The Preselis have Special Area of Conservation status, and there are three sites of special scientific interest ( SSSIs). Name variations A peak is spelt ''Percelye'' o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Craig Rhos-y-felin
Craig Rhos-y-felin is a rocky outcrop on the north side of the Preseli Mountains in Wales, which is designated as a RIGS site on the basis of its geological and geomorphological interest. It is accepted by some in the archaeological community that it is the site of a quarry, used together with one at Carn Goedog, for gathering stones used at Stonehenge, most notably as the source of some of the foliated rhyolite found in the Stonehenge "debitage". This is disputed by others, who believe that all of the features at the site, apart from evidence of intermittent occupation over a long period, are of natural origin. Some believe that the site was used as a quarry in both the Neolithic and Bronze Age The Bronze Age () was a historical period characterised principally by the use of bronze tools and the development of complex urban societies, as well as the adoption of writing in some areas. The Bronze Age is the middle principal period of ...s, around 4000 to 5000 years ago, and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diabase
Diabase (), also called dolerite () or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-grained to aphanitic chilled margins which may contain tachylite (dark mafic glass). ''Diabase'' is the preferred name in North America, while ''dolerite'' is the preferred name in the rest of the English-speaking world, where sometimes the name ''diabase'' refers to altered dolerites and basalts. Some geologists prefer to avoid confusion by using the name ''microgabbro''. The name ''diabase'' comes from the French , and ultimately from the Greek 'act of crossing over, transition', whereas the name ''dolerite'' comes from the French , from the Greek 'deceitful, deceptive', because it was easily confused with diorite. Petrography Diabase normally has a fine but visible texture of euhedral lath-shaped plagioclase crystals (62%) set i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irish Sea Glacier
The British-Irish Ice Sheet (BIIS), a component of which was the Irish Sea Glacier was an ice sheet during the Pleistocene Ice Age that, probably on more than one occasion, flowed southwards from its source areas in Scotland and Ireland and across the Isle of Man, Anglesey and Pembrokeshire. It probably reached its maximum extent during the Anglian Glaciation, and it was also extensive during the Late Devensian Glaciation (or Last Glacial Maximum). Irish Sea Glacier The Irish Sea Glacier was the only clearly defined major glacier in the Irish Sea and flowed about 700 km from its source areas to its southernmost margin. It is sometimes referred to as an “ice stream” since it appears to have been constrained not by ice-free land areas but by highlands which were themselves buried beneath ice. At the time of its maximum extent the glacier extended all the way to the coasts of Somerset and Cornwall, along the south coast of Ireland, and even reached the Isles of Scilly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolerite
Diabase (), also called dolerite () or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-grained to aphanitic chilled margins which may contain tachylite (dark mafic glass). ''Diabase'' is the preferred name in North America, while ''dolerite'' is the preferred name in the rest of the English-speaking world, where sometimes the name ''diabase'' refers to altered dolerites and basalts. Some geologists prefer to avoid confusion by using the name ''microgabbro''. The name ''diabase'' comes from the French , and ultimately from the Greek 'act of crossing over, transition', whereas the name ''dolerite'' comes from the French , from the Greek 'deceitful, deceptive', because it was easily confused with diorite. Petrography Diabase normally has a fine but visible texture of euhedral lath-shaped plagioclase crystals (62%) set in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blue Brick
Blue is one of the three primary colours in the RYB colour model (traditional colour theory), as well as in the RGB (additive) colour model. It lies between violet and cyan on the spectrum of visible light. The term ''blue'' generally describes colours perceived by humans observing light with a dominant wavelength that's between approximately 450 and 495 nanometres. Most blues contain a slight mixture of other colours; azure contains some green, while ultramarine contains some violet. The clear daytime sky and the deep sea appear blue because of an optical effect known as Rayleigh scattering. An optical effect called the Tyndall effect explains blue eyes. Distant objects appear more blue because of another optical effect called aerial perspective. Blue has been an important colour in art and decoration since ancient times. The semi-precious stone lapis lazuli was used in ancient Egypt for jewellery and ornament and later, in the Renaissance, to make the pigment ultr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boscombe Bowmen
The Boscombe Bowmen is the name given by archaeologists to a group of early Bronze Age (Bell Beaker) people found in a shared burial at Boscombe Down in Amesbury () near Stonehenge in Wiltshire, England. Discovery The burials were found in 2003 during roadworks being carried out on behalf of Qinetiq, the contractor that operates the Boscombe Down military airfield. The site is near a group of houses (known as Lower Camp) in Amesbury which are associated with the airfield (which lies to the east). The burials The grave contained the remains of at least nine individuals including several juveniles, five adult males and the cremated remains of an infant. Analysis of the skulls suggests that the men and the teenager were related to each other. The eldest man was buried in a crouched position with the bones of the others scattered around him, and their skulls resting at his feet. They became known as the Bowmen because several flint arrowheads were placed in the grave. Other grave g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Naked Science Episodes
The following is a list of episodes of '' Naked Science'', an American documentary A documentary film (often described simply as a documentary) is a nonfiction Film, motion picture intended to "document reality, primarily for instruction, education or maintaining a Recorded history, historical record". The American author and ... television series which premiered in 2004 on the National Geographic Channel. Episode list Season 1 Season 2 Season 3 Season 4 Season 5 Season 6 Season 7 Season 8 External links * *Naked Science at Yidio {{DEFAULTSORT:Naked Science episodes, List of Lists of American non-fiction television series episodes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacial Erratic
A glacial erratic is a glacially deposited rock (geology), rock differing from the type of country rock (geology), rock native to the area in which it rests. Erratics, which take their name from the Latin word ' ("to wander"), are carried by glacial ice, often over distances of hundreds of kilometres. Erratics can range in size from pebbles to large boulders such as Okotoks Erratic, Big Rock (16,500 metric tons) in Alberta. Geologists identify erratics by studying the rocks surrounding the position of the erratic and the composition of the erratic itself. Erratics are significant because: *They can be transported by glaciers, and are thereby one of a series of indicators which mark the path of prehistoric Glacial motion, glacier movement. Their lithographic origin can be traced to the parent bedrock, allowing for confirmation of the ice flow route. *They can be transported by ice rafting, which allows quantification of the extent of glacial flooding resulting from ice dam failure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaciation
A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate between glacial periods. The Last Glacial Period ended about 15,000 years ago. The Holocene is the current interglacial. A time with no glaciers on Earth is considered a greenhouse climate state. Quaternary Period Within the Quaternary, which started about 2.6 million years before present, there have been a number of glacials and interglacials. At least eight glacial cycles have occurred in the last 740,000 years alone. Changes in atmospheric and associated radiative forcing were among the primary drivers of globally cold glacial and warm interglacial climates, with changes in ocean physical circulation, biological productivity and seawater acid-base chemistry likely causing most of the recorded changes Penultimate Glacial Period The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wales
Wales ( ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by the Irish Sea to the north and west, England to the England–Wales border, east, the Bristol Channel to the south, and the Celtic Sea to the south-west. , it had a population of 3.2 million. It has a total area of and over of Coastline of Wales, coastline. It is largely mountainous with its higher peaks in the north and central areas, including Snowdon (), its highest summit. The country lies within the Temperate climate, north temperate zone and has a changeable, Oceanic climate, maritime climate. Its capital and largest city is Cardiff. A distinct Culture of Wales, Welsh culture emerged among the Celtic Britons after the End of Roman rule in Britain, Roman withdrawal from Britain in the 5th century, and Wales was briefly united under Gruffudd ap Llywelyn in 1055. After over 200 years of war, the Conquest of Wales by Edward I, conquest of Wales by King Edward I o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
