1.
North America
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North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere. It can also be considered a subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea. North America covers an area of about 24,709,000 square kilometers, about 16. 5% of the land area. North America is the third largest continent by area, following Asia and Africa, and the fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 565 million people in 23 independent states, or about 7. 5% of the worlds population, North America was reached by its first human populations during the last glacial period, via crossing the Bering land bridge. The so-called Paleo-Indian period is taken to have lasted until about 10,000 years ago, the Classic stage spans roughly the 6th to 13th centuries. The Pre-Columbian era ended with the migrations and the arrival of European settlers during the Age of Discovery. Present-day cultural and ethnic patterns reflect different kind of interactions between European colonists, indigenous peoples, African slaves and their descendants, European influences are strongest in the northern parts of the continent while indigenous and African influences are relatively stronger in the south. Because of the history of colonialism, most North Americans speak English, Spanish or French, the Americas are usually accepted as having been named after the Italian explorer Amerigo Vespucci by the German cartographers Martin Waldseemüller and Matthias Ringmann. Vespucci, who explored South America between 1497 and 1502, was the first European to suggest that the Americas were not the East Indies, but a different landmass previously unknown by Europeans. In 1507, Waldseemüller produced a map, in which he placed the word America on the continent of South America. He explained the rationale for the name in the accompanying book Cosmographiae Introductio, for Waldseemüller, no one should object to the naming of the land after its discoverer. He used the Latinized version of Vespuccis name, but in its feminine form America, following the examples of Europa, Asia and Africa. Later, other mapmakers extended the name America to the continent, In 1538. Some argue that the convention is to use the surname for naming discoveries except in the case of royalty, a minutely explored belief that has been advanced is that America was named for a Spanish sailor bearing the ancient Visigothic name of Amairick. Another is that the name is rooted in a Native American language, the term North America maintains various definitions in accordance with location and context. In Canadian English, North America may be used to refer to the United States, alternatively, usage sometimes includes Greenland and Mexico, as well as offshore islands
2.
Canadian Shield
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Composed of igneous rock resulting from its long volcanic history, the area is covered by a thin layer of soil. Human population is sparse, and industrial development is minimal, while mining is prevalent, the Canadian Shield is a physiographic division, consisting of five smaller, physiographic provinces, the Laurentian Upland, Kazan Region, Davis, Hudson and James. The shield extends into the United States as the Adirondack Mountains, the Canadian Shield is U-shaped and is a subsection of the Laurentia craton signifying the area of greatest glacial impact creating the thin soils. The Canadian Shield is more than 3.96 billion years old, the Canadian Shield once had jagged peaks, higher than any of todays mountains, but millions of years of erosion have changed these mountains to rolling hills. The Canadian Shield was the first part of North America to be elevated above sea level and has remained almost wholly untouched by successive encroachments of the sea upon the continent. It is the Earths greatest area of exposed Archean rock, the metamorphic base rocks are mostly from the Precambrian Supereon, and have been repeatedly uplifted and eroded. Today it consists largely of an area of low relief 300 to 610 m above sea level with a few monadnocks, during the Pleistocene Epoch, continental ice sheets depressed the land surface, scooped out thousands of lake basins, and carried away much of the regions soil. When the Greenland section is included, the Shield is approximately circular, bounded on the northeast by the northeast edge of Greenland and it covers much of Greenland, Labrador, most of Quebec north of the St. In total, the area of the Shield covers approximately 8,000,000 km2. The underlying rock structure also includes Hudson Bay, the Canadian Shield is among the oldest on earth, with regions dating from 2.5 to 4.2 billion years. The multitude of rivers and lakes in the region is caused by the watersheds of the area being so young. It has some of the oldest volcanoes on the planet and it has over 150 volcanic belts whose bedrock ranges from 600 to 1200 million years old. Each belt probably grew by the coalescence of accumulations erupted from numerous vents, many of Canadas major ore deposits are associated with Precambrian volcanoes. The Sturgeon Lake Caldera in Kenora District, Ontario, is one of the worlds best preserved mineralized Neoarchean caldera complexes, the Canadian Shield also contains the Mackenzie dike swarm, which is the largest dike swarm known on Earth. Mountains have deep roots and float on the denser mantle much like an iceberg at sea, as mountains erode, their roots rise and are eroded in turn. The rocks that now form the surface of the Shield were once far below the Earths surface, the high pressures and temperatures at those depths provided ideal conditions for mineralization. Although these mountains are now eroded, many large mountains still exist in Canadas far north called the Arctic Cordillera. This is a vast deeply dissected mountain range, stretching from northernmost Ellesmere Island to the northernmost tip of Labrador, the ranges highest peak is Nunavuts Barbeau Peak at 2,616 metres above sea level
3.
Great Plains
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The region is known for supporting extensive cattle ranching and dry farming. The Canadian portion of the Plains is known as the Prairies, some geographers include some territory of northern Mexico in the Plains, but many stop at the Rio Grande. The term Great Plains is used in the United States to describe a sub-section of the even more vast Interior Plains physiographic division and it also has currency as a region of human geography, referring to the Plains Indians or the Plains States. There is no region referred to as the Great Plains in The Atlas of Canada, in terms of human geography, the term prairie is more commonly used in Canada, and the region is known as the Prairie Provinces or simply the Prairies. The region is about 500 mi east to west and 2,000 mi north to south, much of the region was home to American bison herds until they were hunted to near extinction during the mid/late 19th century. It has an area of approximately 500,000 sq mi, current thinking regarding the geographic boundaries of the Great Plains is shown by this map at the Center for Great Plains Studies, University of Nebraska–Lincoln. The term Great Plains, for the region west of about the 96th or 98th meridian, nevin Fennemans 1916 study, Physiographic Subdivision of the United States, brought the term Great Plains into more widespread usage. Before that the region was almost invariably called the High Plains, today the term High Plains is used for a subregion of the Great Plains. The Great Plains are the westernmost portion of the vast North American Interior Plains, during the Cretaceous Period, the Great Plains were covered by a shallow inland sea called the Western Interior Seaway. However, during the Late Cretaceous to the Paleocene, the seaway had begun to recede, leaving thick marine deposits. During the Cenozoic era, specifically about 25 million years ago during the Miocene and Pliocene epochs, existing forest biomes declined and grasslands became much more widespread. The grasslands provided a new niche for mammals, including many ungulates and glires, traditionally, the spread of grasslands and the development of grazers have been strongly linked. The vast majority of animals became extinct in North America at the end of the Pleistocene. In general, the Great Plains have a variety of weather through the year, with very cold and harsh winters and very hot. Wind speeds are very high, especially in winter. Grasslands are among the least protected biomes, humans have converted much of the prairies for agricultural purposes or to create pastures. The Great Plains have dust storms mostly every year or so, the 100th meridian roughly corresponds with the line that divides the Great Plains into an area that receive 20 in or more of rainfall per year and an area that receives less than 20 in. The region is subjected to extended periods of drought, high winds in the region may then generate devastating dust storms
4.
Great Lakes
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Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth, containing 21% of the worlds surface fresh water by volume. The total surface is 94,250 square miles, and the volume is 5,439 cubic miles. Due to their sea-like characteristics the five Great Lakes have also long been referred to as inland seas, Lake Superior is the second largest lake in the world by area, and Lake Michigan is the largest lake that is entirely within one country. The southern half of the Great Lakes is bordered by the Great Lakes Megalopolis, the lakes have been a major highway for transportation, migration and trade, and they are home to a large number of aquatic species. Many invasive species have been introduced due to trade, and some threaten the regions biodiversity, though the five lakes reside in separate basins, they form a single, naturally interconnected body of fresh water, within the Great Lakes Basin. The lakes form a chain connecting the interior of North America to the Atlantic Ocean. From the interior to the outlet at the Saint Lawrence River, water flows from Superior to Huron and Michigan, southward to Erie, the lakes drain a large watershed via many rivers, and are studded with approximately 35,000 islands. There are also several smaller lakes, often called inland lakes. The surface area of the five primary lakes combined is roughly equal to the size of the United Kingdom, while the area of the entire basin is about the size of the UK. Lake Michigan is the one of the Great Lakes that is located entirely within the United States. The lakes are divided among the jurisdictions of the Canadian province of Ontario and the U. S. states of Minnesota, Wisconsin, Michigan, Illinois, Indiana, Ohio, Pennsylvania, and New York. Both Ontario and Michigan include in their boundaries portions of four of the lakes, Ontario does not border Lake Michigan, New York and Wisconsins jurisdictions extend into two lakes, and the remaining states into one of the lakes. This designation, however, is not universal and those living on the shore of Lake Superior often refer to all the other lakes as the lower lakes, because they are farther south. This corresponds to thinking of Lakes Erie and Ontario as down south, vessels sailing north on Lake Michigan are considered upbound even though they are sailing toward its effluent current. The Chicago River and Calumet River systems connect the Great Lakes Basin to the Mississippi River System through man-made alterations, the St. Marys River, including the Soo Locks, connects Lake Superior to Lake Huron. The Straits of Mackinac connect Lake Michigan to Lake Huron, the St. Clair River connects Lake Huron to Lake St. Clair. The Detroit River connects Lake St. Clair to Lake Erie, the Niagara River, including Niagara Falls, connects Lake Erie to Lake Ontario. The Welland Canal, bypassing the Falls, connects Lake Erie to Lake Ontario, the Saint Lawrence River connects Lake Ontario to the Gulf of St. Lawrence, which connects to the Atlantic Ocean
5.
Metamorphic rock
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Metamorphic rocks arise from the transformation of existing rock types, in a process called metamorphism, which means change in form. The original rock is subjected to heat and pressure, causing profound physical and/or chemical change, the protolith may be a sedimentary, an igneous, or even an existing type of metamorphic rock. Metamorphic rocks make up a part of the Earths crust. They are classified by texture and by chemical and mineral assemblage and they may be formed simply by being deep beneath the Earths surface, subjected to high temperatures and the great pressure of the rock layers above it. They can form from tectonic processes such as continental collisions, which cause horizontal pressure and they are also formed when rock is heated up by the intrusion of hot molten rock called magma from the Earths interior. The study of rocks provides information about the temperatures and pressures that occur at great depths within the Earths crust. Some examples of rocks are gneiss, slate, marble, schist. Metamorphic minerals are those that only at the high temperatures and pressures associated with the process of metamorphism. These minerals, known as index minerals, include sillimanite, kyanite, staurolite, andalusite, and some garnet. Other minerals, such as olivines, pyroxenes, amphiboles, micas, feldspars, and quartz, may be found in metamorphic rocks and these minerals formed during the crystallization of igneous rocks. They are stable at temperatures and pressures and may remain chemically unchanged during the metamorphic process. However, all minerals are only within certain limits. The change in the size of the rock during the process of metamorphism is called recrystallization. Both high temperatures and pressures contribute to recrystallization, high temperatures allow the atoms and ions in solid crystals to migrate, thus reorganizing the crystals, while high pressures cause solution of the crystals within the rock at their point of contact. The layering within metamorphic rocks is called foliation, and it occurs when a rock is being shortened along one axis during recrystallization. This causes the platy or elongated crystals of minerals, such as mica and chlorite and this results in a banded, or foliated rock, with the bands showing the colors of the minerals that formed them. Textures are separated into foliated and non-foliated categories, foliated rock is a product of differential stress that deforms the rock in one plane, sometimes creating a plane of cleavage. For example, slate is a metamorphic rock, originating from shale
6.
Igneous rock
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Igneous rock, or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava, the magma can be derived from partial melts of existing rocks in either a planets mantle or crust. Typically, the melting is caused by one or more of three processes, an increase in temperature, a decrease in pressure, or a change in composition, solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, Igneous and metamorphic rocks make up 90–95% of the top 16 km of the Earths crust by volume. Igneous rocks form about 15% of the Earths current land surface, most of the Earths oceanic crust is made of igneous rock. In terms of modes of occurrence, igneous rocks can be either intrusive or extrusive, the mineral grains in such rocks can generally be identified with the naked eye. Intrusive rocks can also be classified according to the shape and size of the intrusive body, typical intrusive formations are batholiths, stocks, laccoliths, sills and dikes. When the magma solidifies within the earths crust, it cools slowly forming coarse textured rocks, such as granite, gabbro, the central cores of major mountain ranges consist of intrusive igneous rocks, usually granite. When exposed by erosion, these cores may occupy huge areas of the Earths surface, intrusive igneous rocks that form at depth within the crust are termed plutonic rocks and are usually coarse-grained. Intrusive igneous rocks that form near the surface are termed subvolcanic or hypabyssal rocks, hypabyssal rocks are less common than plutonic or volcanic rocks and often form dikes, sills, laccoliths, lopoliths, or phacoliths. Extrusive igneous rocks, also known as rocks, are formed at the crusts surface as a result of the partial melting of rocks within the mantle. Extrusive igneous rocks cool and solidify quicker than intrusive igneous rocks and they are formed by the cooling of molten magma on the earths surface. The magma, which is brought to the surface through fissures or volcanic eruptions, hence such rocks are smooth, crystalline and fine-grained. Basalt is an extrusive igneous rock and forms lava flows, lava sheets. Some kinds of basalt solidify to form long polygonal columns, the Giants Causeway in Antrim, Northern Ireland is an example. The molten rock, with or without suspended crystals and gas bubbles, is called magma and it rises because it is less dense than the rock from which it was created. When magma reaches the surface from beneath water or air, it is called lava, eruptions of volcanoes into air are termed subaerial, whereas those occurring underneath the ocean are termed submarine. Black smokers and mid-ocean ridge basalt are examples of volcanic activity
7.
Black Hills
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The Black Hills are a small, isolated mountain range rising from the Great Plains of North America in western South Dakota and extending into Wyoming, United States. Black Elk Peak, which rises to 7,244 feet, is the ranges highest summit, the Black Hills encompass the Black Hills National Forest. The name Black Hills is a translation of the Lakota Pahá Sápa, the hills were so-called because of their dark appearance from a distance, as they were covered in trees. Native Americans have a history in the Black Hills. After conquering the Cheyenne in 1776, the Lakota took over the territory of the Black Hills, however, when settlers discovered gold there in 1874, as a result of George Armstrong Custers Black Hills Expedition, miners swept into the area in a gold rush. As the economy of the Black Hills has shifted from natural resources since the late 20th century, locals tend to divide the Black Hills into two areas, The Southern Hills and The Northern Hills. Attractions in the Northern Hills include Spearfish Canyon, historic Deadwood, the first Rally was held on August 14,1938 and the 75th Rally in 2015 saw more than 1 million bikers visit the Black Hills. Devils Tower National Monument, located in the Wyoming Black Hills, is an important nearby attraction and was the United States first national monument. Scientists have been able to utilize carbon-dating to evaluate the age of tools found in the area, stratigraphic records indicate environmental changes in the land, such as flood and drought patterns. For example, large-scale flooding of the Black Hill basins occurs at a probability rate of 0.01, however, during The Medieval Climate Anomaly, or the Medieval Warm Period, flooding increased in the basins. The Arikara arrived by AD1500, followed by the Cheyenne, Crow, Kiowa, the Lakota arrived from Minnesota in the 18th century and drove out the other tribes, who moved west. They claimed the land, which they called Ȟe Sápa, the mountains commonly became known as the Black Hills. François and Louis de La Vérendrye probably travelled near the Black Hills in 1743, fur trappers and traders had some dealings with the Native Americans. European Americans increasingly encroached on Lakota territory, in this treaty, they protected the Black Hills forever from European-American settlement. Both the Sioux and Cheyenne also claimed rights to the land, saying that in their cultures, it was considered the axis mundi, an official announcement of gold was made by the newspaper reporters accompanying the expedition. The following year, the Newton-Jenney Party conducted the first detailed survey of the Black Hills, the surveyor for the party, Dr. Valentine McGillycuddy, was the first European American to ascend to the top of Black Elk Peak. This highest point in the Black Hills is 7,242 feet above sea level, during the 1875–1878 gold rush, thousands of miners went to the Black Hills, in 1880, the area was the most densely populated part of the Dakota Territory. Three large towns developed in the Northern Hills, Deadwood, Central City, around these were groups of smaller gold camps, towns, and villages
8.
South Dakota
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South Dakota is a state located in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux Native American tribes, South Dakota is the 17th most expansive, but the 5th least populous and the 5th least densely populated of the 50 United States. Once the southern portion of the Dakota Territory, South Dakota became a state on November 2,1889, Pierre is the state capital and Sioux Falls, with a population of about 171,000, is South Dakotas largest city. South Dakota is bordered by the states of North Dakota, Minnesota, Iowa, Nebraska, Wyoming, the state is bisected by the Missouri River, dividing South Dakota into two geographically and socially distinct halves, known to residents as East River and West River. Eastern South Dakota is home to most of the states population, West of the Missouri, ranching is the predominant agricultural activity, and the economy is more dependent on tourism and defense spending. Most of the Native American reservations are located in West River, the Black Hills, a group of low pine-covered mountains sacred to the Sioux, are located in the southwest part of the state. Mount Rushmore, a major tourist destination, is located there, South Dakota experiences a temperate continental climate, with four distinct seasons and precipitation ranging from moderate in the east to semi-arid in the west. The ecology of the state features species typical of a North American grassland biome, humans have inhabited the area for several millennia, with the Sioux becoming dominant by the early 19th century. In the late 19th century, European-American settlement intensified after a rush in the Black Hills. Encroaching miners and settlers triggered a number of Indian wars, ending with the Wounded Knee Massacre in 1890, historically dominated by an agricultural economy and a rural lifestyle, South Dakota has recently sought to diversify its economy in areas to attract and retain residents. South Dakotas history and rural character still strongly influence the culture of the state, South Dakota is situated in the north-central United States, and is considered a part of the Midwest by the U. S. Census Bureau, it is also part of the Great Plains region. The culture, economy, and geography of western South Dakota have more in common with the West than the Midwest, South Dakota has a total area of 77,116 square miles, making the state the 17th largest in the Union. Black Elk Peak, formerly named Harney Peak, with an elevation of 7,242 ft, is the states highest point, while the shoreline of Big Stone Lake is the lowest, with an elevation of 966 ft. South Dakota is bordered to the north by North Dakota, to the south by Nebraska, to the east by Iowa and Minnesota, the geographical center of the U. S. is 17 miles west of Castle Rock in Butte County. The North American continental pole of inaccessibility is located between Allen and Kyle,1,024 mi from the nearest coastline, the Missouri River is the largest and longest river in the state. Other major South Dakota rivers include the Cheyenne, James, Big Sioux, Eastern South Dakota has many natural lakes, mostly created by periods of glaciation. Additionally, dams on the Missouri River create four large reservoirs, Lake Oahe, Lake Sharpe, Lake Francis Case, South Dakota can generally be divided into three regions, eastern South Dakota, western South Dakota, and the Black Hills. The Missouri River serves as a boundary in terms of geographic, social, at times the Black Hills are combined with the rest of western South Dakota, and people often refer to the resulting two regions divided by the Missouri River as West River and East River
9.
United States
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Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
10.
Sediment
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For sediment in beverages, see dregs. For example, sand and silt can be carried in suspension in water and on reaching the sea be deposited by sedimentation. Sediments are most often transported by water, but also wind, beach sands and river channel deposits are examples of fluvial transport and deposition, though sediment also often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of transport and deposition. Glacial moraine deposits and till are ice-transported sediments, sediment can be classified based on its grain size and/or its composition. Sediment size is measured on a log base 2 scale, called the Phi scale, composition of sediment can be measured in terms of, parent rock lithology mineral composition chemical make-up. This leads to an ambiguity in which clay can be used as both a size-range and a composition, sediment is transported based on the strength of the flow that carries it and its own size, volume, density, and shape. Stronger flows will increase the lift and drag on the particle, causing it to rise, rivers and streams carry sediment in their flows. This sediment can be in a variety of locations within the flow and these relationships are shown in the following table for the Rouse number, which is a ratio of sediment fall velocity to upwards velocity. If the upwards velocity is less than the settling velocity, but still high enough for the sediment to move, it will move along the bed as bed load by rolling, sliding. If the upwards velocity is higher than the velocity, the sediment will be transported high in the flow as wash load. As there are generally a range of different particle sizes in the flow, sediment motion can create self-organized structures such as ripples, dunes, antidunes on the river or stream bed. These bedforms are often preserved in rocks and can be used to estimate the direction. Overland flow can erode soil particles and transport them downslope, the erosion associated with overland flow may occur through different methods depending on meteorological and flow conditions. If the initial impact of rain droplets dislodges soil, the phenomenon is called rainsplash erosion, if overland flow is directly responsible for sediment entrainment but does not form gullies, it is called sheet erosion. If the flow and the substrate permit channelization, gullies may form, glaciers carry a wide range of sediment sizes, and deposit it in moraines. The overall balance between sediment in transport and sediment being deposited on the bed is given by the Exner equation and this expression states that the rate of increase in bed elevation due to deposition is proportional to the amount of sediment that falls out of the flow. This can be localized, and simply due to obstacles, examples are scour holes behind boulders, where flow accelerates
