Roads consist of one or two roadways, each with one or more lanes and any associated sidewalks and road verges. Roads that are available for use by the public may be referred to as parkways, freeways, highways, or primary and tertiary local roads. In urban areas roads may diverge through a city or village and be named as streets, serving a function as urban space easement. Modern roads are normally smoothed, paved, or otherwise prepared to allow easy travel, historically many roads were simply recognizable routes without any formal construction or maintenance. In the United Kingdom there is ambiguity between the terms highway and road. The Highway code details rules for road users and this includes footpaths and cycle tracks, and road and driveways on private land and many car parks. Vehicle Excise Duty, a use tax, is payable on some vehicles used on the public road. The definition of a road depends on the definition of a highway, in the United States, laws distinguish between public roads, which are open to public use, and private roads, which are privately controlled.
The assertion that the first pathways were the trails made by animals has not been universally accepted, others believe that some roads originated from following animal trails. The Icknield Way is given as an example of type of road origination. By about 10,000 BC, rough roads/pathways were used by human travelers, the worlds oldest known paved road was constructed in Egypt some time between 2600 and 2200 BC. Stone-paved streets are found in the city of Ur in the Middle East dating back to 4000 BC, corduroy roads are found dating to 4000 BC in Glastonbury, England. The Sweet Track, a timber causeway in England, is one of the oldest engineered roads discovered. Built in winter 3807 BC or spring 3806 BC, tree-ring dating enabled very precise dating and it was claimed to be the oldest road in the world until the 2009 discovery of a 6, 000-year-old trackway in Plumstead, London. Brick-paved streets were used in India as early as 3000 BC, in 500 BC, Darius I the Great started an extensive road system for Persia, including the Royal Road, which was one of the finest highways of its time.
The road remained in use after Roman times, a hybrid of road transport and ship transport beginning in about 1740 is the horse-drawn boat in which the horse follows a cleared path along the river bank. From about 312 BC, the Roman Empire built straight strong stone Roman roads throughout Europe and North Africa, at its peak the Roman Empire was connected by 29 major roads moving out from Rome and covering 78,000 kilometers or 52,964 Roman miles of paved roads. In the 8th century AD, many roads were built throughout the Arab Empire, the most sophisticated roads were those in Baghdad, which were paved with tar
The Jurassic is a geologic period and system that spans 56.3 million years from the end of the Triassic Period 201.3 million years ago to the beginning of the Cretaceous Period 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era, known as the Age of Reptiles, the start of the period is marked by the major Triassic–Jurassic extinction event. The Jurassic is named after the Jura Mountains within the European Alps, by the beginning of the Jurassic, the supercontinent Pangaea had begun rifting into two landmasses, Laurasia to the north and Gondwana to the south. This created more coastlines and shifted the continental climate from dry to humid, on land, the fauna transitioned from the Triassic fauna, dominated by both dinosauromorph and crocodylomorph archosaurs, to one dominated by dinosaurs alone. The first birds appeared during the Jurassic, having evolved from a branch of theropod dinosaurs, other major events include the appearance of the earliest lizards, and the evolution of therian mammals, including primitive placentals.
Crocodilians made the transition from a terrestrial to a mode of life. The oceans were inhabited by marine reptiles such as ichthyosaurs and plesiosaurs, the chronostratigraphic term Jurassic is directly linked to the Jura Mountains. The name Jura is derived from the Celtic root jor, which was Latinised into juria, the Jurassic period is divided into the Early Jurassic and Late Jurassic epochs. The Jurassic System, in stratigraphy, is divided into the Lower Jurassic, the separation of the term Jurassic into three sections goes back to Leopold von Buch. The Jurassic North Atlantic Ocean was relatively narrow, while the South Atlantic did not open until the following Cretaceous period, the Tethys Sea closed, and the Neotethys basin appeared. Climates were warm, with no evidence of glaciation, as in the Triassic, there was apparently no land over either pole, and no extensive ice caps existed. In contrast, the North American Jurassic record is the poorest of the Mesozoic, the Jurassic was a time of calcite sea geochemistry in which low-magnesium calcite was the primary inorganic marine precipitate of calcium carbonate.
Carbonate hardgrounds were thus very common, along with calcitic ooids, calcitic cements, the first of several massive batholiths were emplaced in the northern American cordillera beginning in the mid-Jurassic, marking the Nevadan orogeny. Important Jurassic exposures are found in Russia, South America, Australasia. As the Jurassic proceeded and more groups of dinosaurs like sauropods and ornithopods proliferated in Africa. Middle Jurassic strata are well represented nor well studied in Africa. Late Jurassic strata are poorly represented apart from the spectacular Tendaguru fauna in Tanzania, the Late Jurassic life of Tendaguru is very similar to that found in western North Americas Morrison Formation. During the Jurassic period, the primary living in the sea were fish
Kayenta, Arizona is a settlement in the Navajo reservation. This rock formation is prominent in southeastern Utah, where it is seen in the main attractions of a number of national parks. These include Zion National Park, Capitol Reef National Park, the San Rafael Swell, the Kayenta Formation frequently appears as a thinner dark broken layer below Navajo Sandstone and above Wingate Sandstone. Together, these three formations can result in immense vertical cliffs of 2,000 feet or more, Kayenta layers are typically red to brown in color, forming broken ledges. In most sections that include all three formations of the Glen Canyon group the Kayenta is easily recognized. Even at a distance it appears as a dark-red and its position is generally marked by a topographic break. Its weak beds form a bench or platform developed by stripping the Navajo sandstone back from the face of the Wingate cliffs, the Kayenta is made up of beds of sandstone and limestone, all lenticular, uneven at their tops, and discontinuous within short distances.
They suggest deposits made by shifting streams of fluctuating volume, the sandstone beds, from less than 1-inch to more than 10 feet thick, are composed of relatively coarse, well-rounded quartz grains cemented by lime and iron. The thicker beds are indefinitely cross bedded, the shales are essentially fine-grained, very thin sandstones that include lime concretions and balls of consolidated mud. The limestone appears as solid gray-blue beds, a few inches to a few feet thick, most of the limestone lenses are less than 25 feet long, but two were traced for nearly 500 feet and one for 1,650 feet. Viewed as a whole, the Kayenta is readily distinguished from the formations above. It is unlike them in composition, manner of bedding, but in many sections the contact between the two formations is unconformable, the basal Kayenta consists of conglomerate and lenticular sandstone that fills depressions eroded in the underlying beds. In Moqui Canyon near Red Cone Spring nearly 10 feet of Kayenta limestone conglomerate rests in a long meandering valley cut in Wingate.
The red and mauve Kayenta siltstones and sandstones that form the slopes at base of the Navajo Sandstone cliffs record the record of low to moderate energy streams, poole has shown that the streams still flowed toward the east depositing from 150 to 210 m of sediment here. The sedimentary structures showing the channel and flood deposits of streams are well exposed on switchbacks below the tunnel in Pine Creek Canyon. In the southeastern part of Zion National Park a stratum of cross bedded sandstone is roughly halfway between the top and bottom of the Kayenta Formation. It is a tongue of sandstone that merges with the Navajo formation east of Kanab and this tongue is the ledge that shades the lower portion of the Emerald Pool Trail, and it is properly called Navajo, not Kayenta. Fossil mudcracks attest to seasonal climate, and thin limestones and fossilized trails of aquatic snails or worms mark the existence of ponds
The province covers an area of 337,000 km2 within western Colorado, northwestern New Mexico and eastern Utah, and northern Arizona. About 90% of the area is drained by the Colorado River and its tributaries, the Green, San Juan. Most of the remainder of the plateau is drained by the Rio Grande, the Colorado Plateau is largely made up of high desert, with scattered areas of forests. In the southwest corner of the Colorado Plateau lies the Grand Canyon of the Colorado River, much of the Plateaus landscape is related, in both appearance and geologic history, to the Grand Canyon. The nickname Red Rock Country suggests the brightly colored rock left bare to the view by dryness, hoodoos, reefs, river narrows, natural bridges, and slot canyons are only some of the additional features typical of the Plateau. The Colorado Plateau has the greatest concentration of U. S. National Park Service units in the country outside of the Washington, DC metropolitan area. Among its ten National Parks are Grand Canyon, Glen Canyon, Bryce Canyon, Capitol Reef, Arches, Mesa Verde, and Petrified Forest.
The province is bounded by the Rocky Mountains in Colorado, and by the Uinta Mountains and Wasatch Mountains branches of the Rockies in northern and it is bounded by the Rio Grande Rift, Mogollon Rim and the Basin and Range Province. Isolated ranges of the Southern Rocky Mountains such as the San Juan Mountains in Colorado, north-south trending normal faults that include the Hurricane, Grand Wash, and Paunsaugunt separate the sections component plateaus. This fault pattern is caused by the forces pulling apart the adjacent Basin and Range province to the west. Occupying the southeast corner of the Colorado Plateau is the Datil Section, thick sequences of mid-Tertiary to late-Cenozoic-aged lava covers this section. Development of the province has in part been influenced by structural features in its oldest rocks. Part of the Wasatch Line and its various faults form the edge of the province. Faults that run parallel to the Wasatch Fault that lies along the Wasatch Range form the boundaries between the plateaus in the High Plateaus Section, the Uinta Basin, Uncompahgre Uplift, and the Paradox Basin were created by movement along structural weaknesses in the regions oldest rock.
Some sources include the Tushar Mountain Plateau as part of the Colorado Plateau, the mostly flat-lying sedimentary rock units that make up these plateaus are found in component plateaus that are between 1500 m to over 3350 m above sea level. A supersequence of these rocks is exposed in the various cliffs, within these rocks are abundant mineral resources that include uranium, coal and natural gas. Study of the unusually clear geologic history has greatly advanced that science. A rain shadow from the Sierra Nevada far to the west, higher areas receive more precipitation and are covered in forests of pine and spruce
Navajo Sandstone frequently overlies and interfingers with the Kayenta Formation of the Glen Canyon Group. Together, these formations can result in immense vertical cliffs of up to 2,200 feet, atop the cliffs, Navajo Sandstone often appears as massive rounded domes and bluffs that are generally white in color. Navajo Sandstone frequently occurs as spectacular cliffs, domes and it can be distinguished from adjacent Jurassic sandstones by its white to light pink color, meter-scale cross-bedding, and distinctive rounded weathering. The wide range of colors exhibited by the Navajo Sandstone reflect a history of alteration by groundwater and other subsurface fluids over the last 190 million years. The iron in these strata originally arrived via the erosion of iron-bearing silicate minerals, this iron accumulated as iron-oxide coatings, which formed slowly after the sand had been deposited. Later, after having been buried, reducing fluids composed of water. The dissolution of the iron coatings by the reducing fluids bleached large volumes of the Navajo Sandstone a brilliant white, reducing fluids transported the iron in solution until they mixed with oxidizing groundwater.
Where the oxidizing and reducing fluids mixed, the iron precipitated within the Navajo Sandstone, the precipitation of iron oxides formed laminea, corrugated layers and pipes of ironstone within the Navajo Sandstone. The age of the Navajo Sandstone is somewhat controversial and it may originate from the Late Triassic but is at least as young as the Early Jurassic stages Pliensbachian and Toarcian. There is no type locality of the name and it was simply named for the Navajo Country of the southwestern United States. The two major subunits of the Navajo are the Lamb Point Tongue and the Shurtz Sandstone Tongue, the Navajo Sandstone was originally named as the uppermost formation of the La Plata Group by Gregory and Stone in 1917. Baker reassigned it as the formation of Glen Canyon Group in 1936. Its age was modified by Lewis and others in 1961, the name was originally not used in northwest Colorado and northeast Utah, where the name Glen Canyon Sandstone was preferred. Its age was modified again by Padian in 1989, the sandstone was deposited in an arid erg on the Western portion of the Supercontinent Pangaea.
This region was affected by monsoons that came about each winter when cooler winds. Theropod tracks are located in Arizona and Utah. Ornithischian tracks located in Arizona, USA, the Navajo Sandstone is well known among rockhounds for its hundreds of thousands of iron oxide concretions. They are believed to represent an extension of Hopi Native American traditions regarding ancestor worship, they are called Moqui marbles after the local proposed Moqui Native American tribe
New South Wales
New South Wales is a state on the east coast of Australia. It borders Queensland to the north, Victoria to the south and it has a coast line with the Tasman Sea on its east side. The Australian Capital Territory is an enclave within the state, New South Wales state capital is Sydney, which is Australias most populous city. In March 2014, the population of New South Wales was 7.5 million. Just under two-thirds of the population,4.67 million. Inhabitants of New South Wales are referred to as New South Welshmen, the Colony of New South Wales was founded as a penal colony in 1788. It originally comprised a more than half of the Australian mainland with its western boundary set at 129th meridian east in 1825, in addition, the colony included the island territories of New Zealand, Van Diemens Land, Lord Howe Island, and Norfolk Island. During the 19th century, most of the area was detached to form separate British colonies that eventually became New Zealand. However, the Swan River Colony has never administered as part of New South Wales.
Lord Howe Island remains part of New South Wales, while Norfolk Island has become a federal Territory, as have the now known as the Australian Capital Territory. The prior inhabitants of New South Wales were the Aboriginal tribes who arrived in Australia about 40,000 to 60,000 years ago, before European settlement there were an estimated 250,000 Aboriginal people in the region. The Wodi Wodi people are the custodians of the Illawarra region of South Sydney. The Bundjalung people are the custodians of parts of the northern coastal areas. The European discovery of New South Wales was made by Captain James Cook during his 1770 survey along the eastern coast of the Dutch-named continent of New Holland. In his original journal covering the survey, in triplicate to satisfy Admiralty Orders, Cook first named the land New Wales, however, in the copy held by the Admiralty, he revised the wording to New South Wales. After years of chaos and anarchy after the overthrow of Governor William Bligh, macquaries legacy is still evident today.
During the 19th century, large areas were separated to form the British colonies of Tasmania, South Australia, Victoria. Responsible government was granted to the New South Wales colony in 1855, following the Treaty of Waitangi, William Hobson declared British sovereignty over New Zealand in 1840
Utah is a state in the western United States. It became the 45th state admitted to the U. S. on January 4,1896, Utah is the 13th-largest by area, 31st-most-populous, and 10th-least-densely populated of the 50 United States. Utah has a population of more than 3 million, approximately 80% of whom live along the Wasatch Front, Utah is bordered by Colorado to the east, Wyoming to the northeast, Idaho to the north, Arizona to the south, and Nevada to the west. It touches a corner of New Mexico in the southeast, approximately 62% of Utahns are reported to be members of The Church of Jesus Christ of Latter-day Saints or LDS, which greatly influences Utahn culture and daily life. The LDS Churchs world headquarters is located in Salt Lake City, Utah is the only state with a majority population belonging to a single church. The state is a center of transportation, information technology and research, government services, mining, in 2013, the U. S. Census Bureau estimated that Utah had the second fastest-growing population of any state.
St. George was the metropolitan area in the United States from 2000 to 2005. Utah has the 14th highest median income and the least income inequality of any U. S. state. A2012 Gallup national survey found Utah overall to be the best state to live in based on 13 forward-looking measurements including various economic, the name Utah is derived from the name of the Ute tribe. It means people of the mountains in the Ute language, according to other sources Utah is derived from the Apache name Yudah which means Tall. These Native American tribes are subgroups of the Ute-Aztec Native American ethnicity and were sedentary, the Ancestral Pueblo people built their homes through excavations in mountains, and the Fremont people built houses of straw before disappearing from the region around the 15th century. Another group of Native Americans, the Navajo, settled in the region around the 18th century, in the mid-18th century, other Uto-Aztecan tribes, including the Goshute, the Paiute, the Shoshone, and the Ute people, settled in the region.
These five groups were present when the first European explorers arrived, the southern Utah region was explored by the Spanish in 1540, led by Francisco Vásquez de Coronado, while looking for the legendary Cíbola. A group led by two Catholic priests—sometimes called the Dominguez-Escalante Expedition—left Santa Fe in 1776, hoping to find a route to the coast of California, the expedition traveled as far north as Utah Lake and encountered the native residents. The Spanish made further explorations in the region, but were not interested in colonizing the area because of its desert nature, in 1821, the year Mexico achieved its independence from Spain, the region became known as part of its territory of Alta California. European trappers and fur traders explored some areas of Utah in the early 19th century from Canada, the city of Provo, Utah was named for one, Étienne Provost, who visited the area in 1825. The city of Ogden, Utah was named after Peter Skene Ogden, in late 1824, Jim Bridger became the first known English-speaking person to sight the Great Salt Lake.
Due to the salinity of its waters, Bridger thought he had found the Pacific Ocean
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles. It is defined by size, being finer than gravel and coarser than silt, Sand can refer to a textural class of soil or soil type, i. e. a soil containing more than 85% sand-sized particles by mass. The second most common type of sand is calcium carbonate, for example aragonite, for example, it is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years like the Caribbean. Sand is a non renewable resource over human timescales, and sand suitable for making concrete is in high demand, in terms of particle size as used by geologists, sand particles range in diameter from 0.0625 mm to 2 mm. An individual particle in this size is termed a sand grain. Sand grains are between gravel and silt, a 1953 engineering standard published by the American Association of State Highway and Transportation Officials set the minimum sand size at 0.074 mm. A1938 specification of the United States Department of Agriculture was 0.05 mm.
Sand feels gritty when rubbed between the fingers. ISO14688 grades sands as fine and coarse with ranges 0.063 mm to 0.2 mm to 0.63 mm to 2.0 mm. In the United States, sand is commonly divided into five sub-categories based on size, very fine sand, fine sand, medium sand, coarse sand, and very coarse sand. These sizes are based on the Krumbein phi scale, where size in Φ = -log2D, on this scale, for sand the value of Φ varies from −1 to +4, with the divisions between sub-categories at whole numbers. The composition of sand is highly variable, depending on the local rock sources. The gypsum sand dunes of the White Sands National Monument in New Mexico are famous for their bright, arkose is a sand or sandstone with considerable feldspar content, derived from weathering and erosion of a granitic rock outcrop. Some sands contain magnetite, glauconite or gypsum, Sands rich in magnetite are dark to black in color, as are sands derived from volcanic basalts and obsidian. Chlorite-glauconite bearing sands are typically green in color, as are sands derived from basaltic with a high olivine content, many sands, especially those found extensively in Southern Europe, have iron impurities within the quartz crystals of the sand, giving a deep yellow color.
Sand deposits in some areas contain garnets and other resistant minerals, the study of individual grains can reveal much historical information as to the origin and kind of transport of the grain. Quartz sand that is weathered from granite or gneiss quartz crystals will be angular. It is called grus in geology or sharp sand in the trade where it is preferred for concrete. Sand that is transported long distances by water or wind will be rounded, people who collect sand as a hobby are known as arenophiles
Salta is a province of Argentina, located in the northwest of the country. Neighboring provinces are from the east clockwise Formosa, Santiago del Estero, Tucumán, to the north it borders Bolivia and Paraguay and to the west lies Chile. The Atacamas lived in the Puna, and the Wichís, in the Chaco region, the first conquistador to venture into the area was Diego de Almagro in 1535, he was followed by Diego de Rojas. Hernando de Lerma founded San Felipe de Lerma in 1582, following orders of the viceroy Francisco de Toledo, Count of Oropesa, by 1650, the city had around five hundred inhabitants. An intendency of Salta del Tucumán was created within the Viceroyalty of the Río de la Plata, in 1774, San Ramón de La Nueva Orán was founded between Salta and Tarija. In 1783, in recognition of the importance of the city. The battle of Salta in 1813 freed the territory from Spain, gervasio de Posadas created the Province of Salta in 1814, containing the current provinces of Salta and parts of southern Bolivia and northern Chile.
Exploiting internal Argentine conflicts that arose after the Argentine Declaration of Independence, in 1834, Jujuy withdrew from Salta and became a separate province. The borders of Salta were further reduced in 1900, with the loss of Yacuiba to Bolivia. The National Government of Los Andes, constituted from the province in 1902 with a capital at San Antonio de los Cobres, was returned to Salta Province in 1943 as the Department of Los Andes. Antonio Alices painting, La muerte de Güemes, which received a Gold Medal at the Centenary Exposition, is on display at the offices of the Salta Provincial Government. The province is located in the zone and has a warm climate in general. The orientation of the Andes influences the distribution of precipitation within the province, the easternmost parts of the province have a semi-arid climate with a dry winter season. The mean annual temperature and precipitation are 20 °C and 500 millimetres, temperatures can reach up to 47 °C during summers, while they can fall down to −5 °C during winters.
The first slopes of the Andes force the moist, easterly winds to rise, provoking very high condensation leading to the formation of clouds that generate copious amounts of rain. The eastern slopes of the mountains receive between 1,000 to 1,500 mm of precipitation a year, although some places receive up to 2,500 mm of precipitation annually owing to orographic precipitation. Most of the precipitation is concentrated in the summer, with winters being dry, the high rainfall on these first slopes creates a thick jungle that extends in a narrow strip along these ranges, creating an area of great species diversity. At higher altitudes on these slopes, the climate is cooler and more humid, with the vegetation consisting of deciduous, between the high altitudes to the east and the low plains to the west lie the valleys
Lava is the molten rock expelled by a volcano during an eruption. The resulting rock after solidification and cooling is called lava. The molten rock is formed in the interior of planets, including Earth. The source of the heat melts the rock within the earth is geothermal energy. When first erupted from a vent, lava is a liquid usually at temperatures from 700 to 1,200 °C. A lava flow is an outpouring of lava, which is created during a non-explosive effusive eruption. When it has stopped moving, lava solidifies to form igneous rock, the term lava flow is commonly shortened to lava. Although lava can be up to 100,000 times more viscous than water, lava can flow great distances before cooling and solidifying because of its thixotropic, explosive eruptions produce a mixture of volcanic ash and other fragments called tephra, rather than lava flows. The word lava comes from Italian, and is derived from the Latin word labes which means a fall or slide. The first use in connection with extruded magma was apparently in an account written by Francesco Serao on the eruption of Vesuvius between May 14 and June 4,1737.
Serao described a flow of lava as an analogy to the flow of water. The composition of almost all lava of the Earths crust is dominated by silicate minerals, mostly feldspars, pyroxenes, micas, igneous rocks, which form lava flows when erupted, can be classified into three chemical types, felsic and mafic. These classes are primarily chemical, the chemistry of lava tends to correlate with the temperature, its viscosity. Felsic or silicic lavas such as rhyolite and dacite typically form lava spines, most silicic lava flows are extremely viscous, and typically fragment as they extrude, producing blocky autobreccias. Felsic magmas can erupt at temperatures as low as 650 to 750 °C, unusually hot rhyolite lavas, may flow for distances of many tens of kilometres, such as in the Snake River Plain of the northwestern United States. Intermediate or andesitic lavas are lower in aluminium and silica, and usually somewhat richer in magnesium, intermediate lavas form andesite domes and block lavas, and may occur on steep composite volcanoes, such as in the Andes.
Poorer in aluminium and silica than felsic lavas, and commonly hotter, greater temperatures tend to destroy polymerized bonds within the magma, promoting more fluid behaviour and a greater tendency to form phenocrysts. Higher iron and magnesium tends to manifest as a darker groundmass, mafic or basaltic lavas are typified by their high ferromagnesian content, and generally erupt at temperatures in excess of 950 °C
The Canadian Rockies comprise the Canadian segment of the North American Rocky Mountains. They are the part of the Canadian Cordillera, which is a system of multiple ranges of mountains which runs from the Canadian Prairies to the Pacific Coast. The southern end borders Idaho and Montana of the USA, in geographic terms the boundary is at the Canada/US border, but in geological terms it might be considered to be at Marias Pass in northern Montana. The northern end is at the Liard River in northern British Columbia, the Canadian Rockies have numerous high peaks and ranges, such as Mount Robson and Mount Columbia. The Canadian Rockies are composed of shale and limestone, much of the range is protected by national and provincial parks, several of which collectively comprise a World Heritage Site. The Canadian Rockies are the easternmost part of the Canadian Cordillera and they form part of the American Cordillera, an essentially continuous sequence of mountain ranges that runs all the way from Alaska to the very tip of South America.
The Cordillera in turn are the part of the Pacific Ring of Fire that runs all the way around the Pacific Ocean. The Canadian Rockies are bounded on the east by the Canadian Prairies, on the west by the Rocky Mountain Trench, contrary to popular misconception, the Rockies do not extend north into Yukon or Alaska, or west into central British Columbia. North of the Liard River, the Mackenzie Mountains, which are a mountain range. The mountain ranges to the west of the Rocky Mountain Trench in southern British Columbia are called the Columbia Mountains, and are not considered to be part of the Rockies by Canadian geologists. Mount Robson is the highest peak in the Canadian Rockies, but not the highest in British Columbia, since there are higher mountains in the Coast Mountains. Its base is only 985 m above sea level, meaning it has a vertical relief of 2,969 m or nearly 10,000 feet. In addition, it rises the 3 km to its summit in a distance of only 4 km from its base at Kinney Lake, climbing Mount Robson is a challenge suitable for experienced and well-prepared mountaineers, and usually requires a week on the mountain.
Mount Columbia is the second-highest peak in the Canadian Rockies, and is the highest mountain in Alberta, there is a non-technical route to the top involving only kicking steps in the snow, but the approach is across the Columbia Icefield and requires glacier travel and crevasse rescue knowledge. It is normally done in two days, with a night at camp, but some strong skiers have done it from the highway in a day. On the other hand, many others have been stuck in their tents for days waiting for the weather to clear. From the same camp as for Mount Columbia, it is possible to ascend a number of other high peaks in the area, including North Twin, South Twin, Stutfield. Snow Dome is not a peak by Rockies standards
In physical geography, a dune is a hill of loose sand built by wind or the flow of water. Dunes occur in different shapes and sizes, formed by interaction with the flow of air or water, most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter slip face in the lee of the wind. The valley or trough between dunes is called a slack, a dune field is an area covered by extensive sand dunes. Dunes occur, for example, in deserts and along some coasts. Some coastal areas have one or more sets of dunes running parallel to the shoreline directly inland from the beach, in most cases, the dunes are important in protecting the land against potential ravages by storm waves from the sea. Although the most widely distributed dunes are those associated with coastal regions, Dunes can form under the action of water flow, and on sand or gravel beds of rivers and the sea-bed. The modern word dune came into English from French c,1790, which in turn came from Middle Dutch dūne.
Crescent-shaped mounds are generally wider than they are long, the slipfaces are on the concave sides of the dunes. These dunes form under winds that blow consistently from one direction, some types of crescentic dunes move more quickly over desert surfaces than any other type of dune. A group of dunes moved more than 100 metres per year between 1954 and 1959 in Chinas Ningxia Province, and similar speeds have been recorded in the Western Desert of Egypt. The largest crescentic dunes on Earth, with mean crest-to-crest widths of more than three kilometres, are in Chinas Taklamakan Desert. They may be composed of clay, sand, or gypsum, eroded from the floor or shore, transported up the concave side of the dune. Examples in Australia are up to 6.5 km long,1 km wide and they occur in southern and West Africa, and in parts of the western United States, especially Texas. Straight or slightly sinuous sand ridges typically much longer than they are wide are known as linear dunes and they may be more than 160 kilometres long.
Some linear dunes merge to form Y-shaped compound dunes, many form in bidirectional wind regimes. The long axes of these dunes extend in the resultant direction of sand movement, linear loess hills known as pahas are superficially similar. These hills appear to have formed during the last ice age under permafrost conditions dominated by sparse tundra vegetation. Radially symmetrical, star dunes are pyramidal sand mounds with slipfaces on three or more arms that radiate from the center of the mound