96-658: The Iapetus Suture is one of several major geological faults caused by the collision of several ancient land masses forming a suture . It represents in part the remains of what was once the Iapetus Ocean . Iapetus was the father of Atlas in Greek mythology, making his an appropriate name for what used to be called the 'Proto-Atlantic Ocean'. When the Atlantic Ocean opened, in the Cretaceous period, it took
192-561: A writing system , built huge pyramids and temples , had a complex calendar , and developed the concept of zero around 400 CE. The first recorded European references to North America are in Norse sagas where it is referred to as Vinland . The earliest verifiable instance of pre-Columbian trans-oceanic contact by any European culture with the North America mainland has been dated to around 1000 CE. The site , situated at
288-405: A fault as oblique requires both dip and strike components to be measurable and significant. Some oblique faults occur within transtensional and transpressional regimes, and others occur where the direction of extension or shortening changes during the deformation but the earlier formed faults remain active. The hade angle is defined as the complement of the dip angle; it is the angle between
384-582: A fault hosting valuable porphyry copper deposits is northern Chile's Domeyko Fault with deposits at Chuquicamata , Collahuasi , El Abra , El Salvador , La Escondida and Potrerillos . Further south in Chile Los Bronces and El Teniente porphyry copper deposit lie each at the intersection of two fault systems. Faults may not always act as conduits to surface. It has been proposed that deep-seated "misoriented" faults may instead be zones where magmas forming porphyry copper stagnate achieving
480-489: A fault plane, where it becomes locked, are called asperities . Stress builds up when a fault is locked, and when it reaches a level that exceeds the strength threshold, the fault ruptures and the accumulated strain energy is released in part as seismic waves , forming an earthquake . Strain occurs accumulatively or instantaneously, depending on the liquid state of the rock; the ductile lower crust and mantle accumulate deformation gradually via shearing , whereas
576-408: A fault's age by studying soil features seen in shallow excavations and geomorphology seen in aerial photographs. Subsurface clues include shears and their relationships to carbonate nodules , eroded clay, and iron oxide mineralization, in the case of older soil, and lack of such signs in the case of younger soil. Radiocarbon dating of organic material buried next to or over a fault shear
672-427: A hanging wall or foot wall where a thrust fault formed along a relatively weak bedding plane is known as a flat and a section where the thrust fault cut upward through the stratigraphic sequence is known as a ramp . Typically, thrust faults move within formations by forming flats and climbing up sections with ramps. This results in the hanging wall flat (or a portion thereof) lying atop the foot wall ramp as shown in
768-484: A major fault. Synthetic faults dip in the same direction as the major fault while the antithetic faults dip in the opposite direction. These faults may be accompanied by rollover anticlines (e.g. the Niger Delta Structural Style). All faults have a measurable thickness, made up of deformed rock characteristic of the level in the crust where the faulting happened, of the rock types affected by
864-400: A manner that creates multiple listric faults. The fault panes of listric faults can further flatten and evolve into a horizontal or near-horizontal plane, where slip progresses horizontally along a decollement . Extensional decollements can grow to great dimensions and form detachment faults , which are low-angle normal faults with regional tectonic significance. Due to the curvature of
960-421: A non-vertical fault are known as the hanging wall and footwall . The hanging wall occurs above the fault plane and the footwall occurs below it. This terminology comes from mining: when working a tabular ore body, the miner stood with the footwall under his feet and with the hanging wall above him. These terms are important for distinguishing different dip-slip fault types: reverse faults and normal faults. In
1056-664: A period of mountain building called the Laramide orogeny , between 80 and 55 mya. The formation of the Isthmus of Panama that connected the continent to South America arguably occurred approximately 12 to 15 mya, and the Great Lakes (as well as many other northern freshwater lakes and rivers) were carved by receding glaciers about 10,000 years ago. North America is the source of much of what humanity knows about geologic time periods. The geographic area that would later become
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#17327729418511152-590: A powerful earthquake killed seven people in 2009. Volcanic eruptions are common in the region. In 1968, the Arenal Volcano , in Costa Rica, erupted and killed 87 people. Fertile soils from weathered volcanic lavas have made it possible to sustain dense populations in agriculturally productive highland areas. Central America has many mountain ranges ; the longest are the Sierra Madre de Chiapas ,
1248-464: A reverse fault, the hanging wall displaces upward, while in a normal fault the hanging wall displaces downward. Distinguishing between these two fault types is important for determining the stress regime of the fault movement. Faults are mainly classified in terms of the angle that the fault plane makes with the Earth's surface, known as the dip , and the direction of slip along the fault plane. Based on
1344-582: A series of geological events, the Salinic orogeny and Caledonian progeny , all three land masses began to converge upon each other, slowly diminishing the ocean by subducting the oceanic crust. By the end of the Silurian period , approximately 420 million years ago, the ocean had disappeared. The geological fault zone resulting from the continental collision is known as the Iapetus Suture, named after
1440-570: A slightly different line from that of the Iapetus suture, with some originally Laurentian rocks being left behind in north-west Europe and other, Avalonian , rocks remaining as part of Newfoundland . The Iapetus Ocean was an ancient ocean which existed in the Southern Hemisphere approximately 600 million years ago and was bordered by several paleocontinents: Laurentia , Ganderia , Carolinia , Avalonia , and Baltica . During
1536-534: A transatlantic exchange , including migrations of European settlers during the Age of Discovery and the early modern period . Present-day cultural and ethnic patterns reflect interactions between European colonists, indigenous peoples , enslaved Africans , immigrants from Europe, Asia, and descendants of these respective groups. Europe's colonization in North America led to most North Americans speaking European languages, such as English , Spanish , and French , and
1632-540: A variety of reactions, including curiosity, trading, cooperation, resignation, and resistance. The indigenous population declined substantially following European arrival, primarily due to the introduction of Eurasian diseases, such as smallpox , to which the indigenous peoples lacked immunity, and because of violent conflicts with Europeans. Indigenous culture changed significantly and their affiliation with political and cultural groups also changed. Several linguistic groups died out , and others changed quite quickly. On
1728-451: A volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth 's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults . Energy release associated with rapid movement on active faults is
1824-422: Is a horst . A sequence of grabens and horsts on the surface of the Earth produces a characteristic basin and range topography . Normal faults can evolve into listric faults, with their plane dip being steeper near the surface, then shallower with increased depth, with the fault plane curving into the Earth. They can also form where the hanging wall is absent (such as on a cliff), where the footwall may slump in
1920-665: Is a very large continent that extends from north of the Arctic Circle to south of the Tropic of Cancer . Greenland, along with the Canadian Shield , is tundra with average temperatures ranging from 10 to 20 °C (50 to 68 °F), but central Greenland is composed of a very large ice sheet. This tundra radiates throughout Canada, but its border ends near the Rocky Mountains (but still contains Alaska) and at
2016-423: Is a zone of folding close to a fault that likely arises from frictional resistance to movement on the fault. The direction and magnitude of heave and throw can be measured only by finding common intersection points on either side of the fault (called a piercing point ). In practice, it is usually only possible to find the slip direction of faults, and an approximation of the heave and throw vector. The two sides of
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#17327729418512112-524: Is an ancient craton which forms the geologic core of North America; it formed between 1.5 and 1.0 billion years ago during the Proterozoic eon. The Canadian Shield is the largest exposure of this craton. From the Late Paleozoic to Early Mesozoic eras, North America was joined with the other modern-day continents as part of the supercontinent Pangaea , with Eurasia to its east. One of
2208-544: Is defined by the direction of movement of the ground as would be seen by an observer on the opposite side of the fault. A special class of strike-slip fault is the transform fault when it forms a plate boundary. This class is related to an offset in a spreading center , such as a mid-ocean ridge , or, less common, within continental lithosphere , such as the Dead Sea Transform in the Middle East or
2304-546: Is in present-day Panama at the Darien Gap on the Colombia -Panama border, placing almost all of Panama within North America. Alternatively, some geologists physiographically locate its southern limit at the Isthmus of Tehuantepec , Mexico, with Central America extending southeastward to South America from this point. The Caribbean islands, or West Indies, are considered part of North America. The continental coastline
2400-648: Is long and irregular. The Gulf of Mexico is the largest body of water indenting the continent, followed by Hudson Bay . Others include the Gulf of Saint Lawrence and the Gulf of California . Before the Central American isthmus formed, the region had been underwater. The islands of the West Indies delineate a submerged former land bridge , which had connected North and South America via what are now Florida and Venezuela . There are several islands off
2496-543: Is often critical in distinguishing active from inactive faults. From such relationships, paleoseismologists can estimate the sizes of past earthquakes over the past several hundred years, and develop rough projections of future fault activity. Many ore deposits lie on or are associated with faults. This is because the fractured rock associated with fault zones allow for magma ascent or the circulation of mineral-bearing fluids. Intersections of near-vertical faults are often locations of significant ore deposits. An example of
2592-561: Is part of North America geographically. In a geologic sense, Bermuda is not part of the Americas, but an oceanic island that was formed on the fissure of the Mid-Atlantic Ridge over 100 million years ago (mya). The nearest landmass to it is Cape Hatteras , North Carolina . However, Bermuda is often thought of as part of North America, especially given its historical, political and cultural ties to Virginia and other parts of
2688-492: Is particularly clear in the case of detachment faults and major thrust faults . The main types of fault rock include: In geotechnical engineering , a fault often forms a discontinuity that may have a large influence on the mechanical behavior (strength, deformation, etc.) of soil and rock masses in, for example, tunnel , foundation , or slope construction. The level of a fault's activity can be critical for (1) locating buildings, tanks, and pipelines and (2) assessing
2784-707: Is the Morrison Formation of the western U.S. Canada is geologically one of the oldest regions in the world, with more than half of the region consisting of Precambrian rocks that have been above sea level since the beginning of the Palaeozoic era. Canada's mineral resources are diverse and extensive. Across the Canadian Shield and in the north there are large iron, nickel, zinc , copper, gold, lead, molybdenum , and uranium reserves. Large diamond concentrations have been recently developed in
2880-527: Is the humid subtropical climate . This area has the wettest cities in the contiguous U.S. , with annual precipitation reaching 67 in (1,700 mm) in Mobile, Alabama . Stretching from the borders of the humid continental and subtropical climates, and going west to the Sierra Nevada , south to the southern tip of Durango , north to the border with tundra climate, the steppe / desert climates are
2976-533: Is the third-largest continent by size after Asia and Africa , and the fourth-largest continent by population after Asia, Africa, and Europe . As of 2021 , North America's population was estimated as over 592 million people in 23 independent states , or about 7.5% of the world's population. In human geography , the terms "North America" and "North American" can refer to Canada, the United States, Mexico, and Greenland or, alternatively, Canada, Greenland and
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3072-606: Is visible close to the shoreline downhill from the Niarbyl Cafe and Visitor Centre in Niarbyl. The Caledonian orogeny united the northern and southern portions of present-day Great Britain . The Iapetus Suture runs from the Solway Firth to Lindisfarne . The Anglo-Scottish border runs near and roughly parallel to the suture. Fault (geology) In geology , a fault is a planar fracture or discontinuity in
3168-762: The Alpine Fault in New Zealand. Transform faults are also referred to as "conservative" plate boundaries since the lithosphere is neither created nor destroyed. Dip-slip faults can be either normal (" extensional ") or reverse . The terminology of "normal" and "reverse" comes from coal mining in England, where normal faults are the most common. With the passage of time, a regional reversal between tensional and compressional stresses (or vice-versa) might occur, and faults may be reactivated with their relative block movement inverted in opposite directions to
3264-567: The Bering Strait during the Early-Middle Holocene . Prior to the arrival of European explorers and colonists in North America, the natives of North America were divided into many different polities, ranging from small bands of a few families to large empires. They lived in several culture areas , which roughly correspond to geographic and biological zones that defined the representative cultures and lifestyles of
3360-600: The British Columbia Coast , Western Canada , and Northern Canada . In the U.S., they include New England , the Mid-Atlantic , South Atlantic states , East North Central states , West North Central states , East South Central states , West South Central states , Mountain states , and Pacific states . The Great Lakes region and the Pacific Northwest include areas in both Canada and
3456-913: The Caribbean Plate , whereas the Juan de Fuca Plate and Cocos Plate border the North American Plate on its western frontier. The continent can be divided into four great regions (each of which contains many subregions): the Great Plains stretching from the Gulf of Mexico to the Canadian Arctic ; the geologically young, mountainous west, including the Rocky Mountains , the Great Basin , California , and Alaska ;
3552-568: The Cordillera Isabelia , and the Cordillera de Talamanca . Between the mountain ranges lie fertile valleys that are suitable for the people; in fact, most of the population of Honduras, Costa Rica, and Guatemala live in valleys. Valleys are also suitable for the production of coffee, beans, and other crops. The indigenous peoples of the Americas have many creation myths , based on which they assert that they have been present on
3648-465: The East Coast to eastern North Dakota , and stretching down to Kansas , is the humid continental climate featuring intense seasons, with a large amount of annual precipitation, with places like New York City averaging 50 in (1,300 mm). Starting at the southern border of the humid continental climate and stretching to the Gulf of Mexico (whilst encompassing the eastern half of Texas)
3744-620: The Inuit of the high Arctic arrived in North America much later than other native groups, evidenced by the disappearance of Dorset culture artifacts from the archaeological record and their replacement by the Thule people . During the thousands of years of native habitation on the continent, cultures changed and shifted. One of the oldest yet discovered is the Clovis culture (c. 9550–9050 BCE) in modern New Mexico . Later groups include
3840-719: The Mississippian culture and related Mound building cultures, found in the Mississippi River valley and the Pueblo culture of what is now the Four Corners . The more southern cultural groups of North America were responsible for the domestication of many common crops now used around the world, such as tomatoes, squash , and maize . As a result of the development of agriculture in the south, many other cultural advances were made there. The Mayans developed
3936-550: The first official name given to Mexico. North America includes several regions and subregions, each of which have their own respective cultural, economic, and geographic regions. Economic regions include several regions formalized in 20th- and 21st-century trade agreements, including NAFTA between Canada , Mexico , and the United States , and CAFTA between Central America , the Dominican Republic , and
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4032-657: The seismic shaking and tsunami hazard to infrastructure and people in the vicinity. In California, for example, new building construction has been prohibited directly on or near faults that have moved within the Holocene Epoch (the last 11,700 years) of the Earth's geological history. Also, faults that have shown movement during the Holocene plus Pleistocene Epochs (the last 2.6 million years) may receive consideration, especially for critical structures such as power plants, dams, hospitals, and schools. Geologists assess
4128-458: The 1490s, building cities, putting the resident indigenous populations to work, raising crops for Spanish settlers and panning gold to enrich the Spaniards. Much of the indigenous population died due to disease and overwork, spurring the Spaniards on to claim new lands and peoples. An expedition under the command of Spanish settler, Hernán Cortés , sailed westward in 1519 to what turned out to be
4224-630: The Arctic, making Canada one of the world's largest producers. Throughout the Shield, there are many mining towns extracting these minerals. The largest, and best known, is Sudbury , Ontario. Sudbury is an exception to the normal process of forming minerals in the Shield since there is significant evidence that the Sudbury Basin is an ancient meteorite impact crater . The nearby, but less-known Temagami Magnetic Anomaly has striking similarities to
4320-651: The Caribbean islands. France took the western half of Hispaniola and developed Saint-Domingue as a cane sugar producing colony worked by black slave labor. Britain took Barbados and Jamaica , and the Dutch and Danes took islands previously claimed by Spain. Britain did not begin settling on the North American mainland until a hundred years after the first Spanish settlements, since it sought first to control nearby Ireland . The first permanent English settlement
4416-635: The Cod fish", in reference to the abundance of cod fish on the East Coast . Waldseemüller used the Latin version of Vespucci's name, Americus Vespucius, in its feminine form of "America", following the examples of "Europa", "Asia", and "Africa". Americus originated from Medieval Latin Emericus (see Saint Emeric of Hungary ), coming from the Old High German name Emmerich . Map makers later extended
4512-579: The Last Glacial Period, and lasted until about 10,000 years ago when the Archaic period began. The classic stage followed the Archaic period, and lasted from approximately the 6th to 13th centuries. Beginning in 1000 AD, the Norse were the first Europeans to begin exploring and ultimately colonizing areas of North America. In 1492, the exploratory voyages of Christopher Columbus led to
4608-419: The North America's southeastern coast, Spanish explorer Juan Ponce de León , who had accompanied Columbus's second voyage, visited and named in 1513 La Florida . As the colonial period unfolded, Spain, England, and France appropriated and claimed extensive territories in North America eastern and southern coastlines. Spain established permanent settlements on the Caribbean islands of Hispaniola and Cuba in
4704-479: The Sudbury Basin. Its magnetic anomalies are very similar to the Sudbury Basin, and so it could be a second metal-rich impact crater. The Shield is also covered by vast boreal forests that support an important logging industry. The United States can be divided into twelve main geological provinces: Each province has its own geologic history and unique features. The geology of Alaska is typical of that of
4800-535: The U.S. North America occupies the northern portion of the landmass generally referred to as the New World, the Western Hemisphere , the Americas, or simply America, which, in many countries, is considered a single continent with North America a subcontinent . North America is the third-largest continent by area after Asia and Africa . North America's only land connection to South America
4896-736: The US (Mexico being classified as part of Latin America ) or simply Canada and the US (Greenland being classified as either Arctic or European (due to its political status as a part of Denmark) and Mexico classified as Latin American). It is unknown with certainty how and when first human populations first reached North America. People were known to live in the Americas at least 20,000 years ago, but various evidence points to possibly earlier dates. The Paleo-Indian period in North America followed
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#17327729418514992-490: The United States has been the source of more varieties of dinosaurs than any other modern country. According to paleontologist Peter Dodson, this is primarily due to stratigraphy, climate and geography, human resources, and history. Much of the Mesozoic Era is represented by exposed outcrops in the many arid regions of the continent. The most significant Late Jurassic dinosaur-bearing fossil deposit in North America
5088-550: The United States, and Mexico. France , Italy , Portugal , Spain , Romania , Greece , and the countries of Latin America use a six-continent model , with the Americas viewed as a single continent and North America designating a subcontinent comprising Canada , the United States , Mexico, and Saint Pierre and Miquelon (politically part of France), and often including Greenland and Bermuda . North America has historically been known by other names, including Spanish North America, New Spain , and América Septentrional,
5184-579: The United States. North America is divided linguistically and culturally into two primary regions, Anglo-America and Latin America . Anglo-America includes most of North America, Belize , and Caribbean islands with English -speaking populations. There are also regions, including Louisiana and Quebec , with large Francophone populations; in Quebec , French is the official language. . The southern portion of North America includes Central America and non-English speaking Caribbean nations. The north of
5280-547: The area had shifted to the Aztec Empire , whose capital city Tenochtitlan was located further north in the Valley of Mexico . The Aztecs were conquered in 1521 by Hernán Cortés . During the so-called Age of Discovery , Europeans explored overseas and staked claims to various parts of North America, much of which was already settled by indigenous peoples. Upon Europeans' arrival in the " New World ", indigenous peoples had
5376-430: The boundary between the continental margin of Laurentia and Iapetan oceanic rocks, while the Early Ordovician (Penobscot) GRUB Line defines the contact between the vestiges of Iapetus and Ganderia . The Middle Ordovician Red Indian Line is considered the main Iapetan suture zone in that it separates peri-Laurentian and peri-Gondwanan oceanic elements. The Dog Bay Line is a younger feature in the Appalachians and delineates
5472-403: The brittle upper crust reacts by fracture – instantaneous stress release – resulting in motion along the fault. A fault in ductile rocks can also release instantaneously when the strain rate is too great. Slip is defined as the relative movement of geological features present on either side of a fault plane. A fault's sense of slip is defined as the relative motion of the rock on each side of
5568-422: The cause of most earthquakes . Faults may also displace slowly, by aseismic creep . A fault plane is the plane that represents the fracture surface of a fault. A fault trace or fault line is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geologic maps to represent a fault. A fault zone is a cluster of parallel faults. However,
5664-432: The continent maintains recognized regions as well. In contrast to the common definition of North America, which encompasses the whole North American continent, the term "North America" is sometimes used more narrowly to refer only to four nations, Canada, Greenland, Mexico, and the U.S. The U.S. Census Bureau includes Saint Pierre and Miquelon, but excludes Mexico from its definition. The term Northern America refers to
5760-452: The continent's coasts; principally, the Arctic Archipelago, the Bahamas , Turks and Caicos , the Greater and Lesser Antilles , the Aleutian Islands (some of which are in the Eastern Hemisphere proper), the Alexander Archipelago , the many thousand islands of the British Columbia Coast, and Newfoundland. Greenland , a self-governing Danish island, and the world's largest , is on the same tectonic plate (the North American Plate ) and
5856-410: The continent. The vast majority of North America is on the North American Plate. Parts of western Mexico, including Baja California, and of California , including the cities of San Diego , Los Angeles , and Santa Cruz , lie on the eastern edge of the Pacific Plate , with the two plates meeting along the San Andreas Fault . The southernmost portion of the continent and much of the West Indies lie on
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#17327729418515952-604: The cordillera, while the major islands of Hawaii consist of Neogene volcanics erupted over a hot spot . Central America is geologically active with volcanic eruptions and earthquakes occurring from time to time. In 1976 Guatemala was hit by a major earthquake , killing 23,000 people; Managua, the capital of Nicaragua, was devastated by earthquakes in 1931 and 1972, the last one killing about 5,000 people; three earthquakes devastated El Salvador, one in 1986 and two in 2001; one earthquake devastated northern and central Costa Rica in 2009, killing at least 34 people; in Honduras
6048-514: The cultures of the region commonly reflect Western traditions . However, relatively small parts of North America in Canada, the United States, Mexico, and Central America have indigenous populations that continue adhering to their respective pre-European colonial cultural and linguistic traditions. The Americas were named after the Italian explorer Amerigo Vespucci by German cartographers Martin Waldseemüller and Matthias Ringmann . Vespucci explored South America between 1497 and 1502, and
6144-436: The direction of slip, faults can be categorized as: In a strike-slip fault (also known as a wrench fault , tear fault or transcurrent fault ), the fault surface (plane) is usually near vertical, and the footwall moves laterally either left or right with very little vertical motion. Strike-slip faults with left-lateral motion are also known as sinistral faults and those with right-lateral motion as dextral faults. Each
6240-447: The driest in the U.S. Highland climates cut from north to south of the continent, where subtropical or temperate climates occur just below the tropics, as in central Mexico and Guatemala . Tropical climates appear in the island regions and in the subcontinent's bottleneck, found in countries and states bathed by the Caribbean Sea or to the south of the Gulf of Mexico and the Pacific Ocean . Precipitation patterns vary across
6336-408: The end of the Canadian Shield, near the Great Lakes . Climate west of the Cascade Range is described as being temperate weather with average precipitation 20 inches (510 millimeters). Climate in coastal California is described to be Mediterranean , with average temperatures in cities like San Francisco ranging from 57 to 70 °F (14 to 21 °C) over the course of the year. Stretching from
6432-456: The fault and of the presence and nature of any mineralising fluids . Fault rocks are classified by their textures and the implied mechanism of deformation. A fault that passes through different levels of the lithosphere will have many different types of fault rock developed along its surface. Continued dip-slip displacement tends to juxtapose fault rocks characteristic of different crustal levels, with varying degrees of overprinting. This effect
6528-402: The fault concerning the other side. In measuring the horizontal or vertical separation, the throw of the fault is the vertical component of the separation and the heave of the fault is the horizontal component, as in "Throw up and heave out". The vector of slip can be qualitatively assessed by studying any drag folding of strata, which may be visible on either side of the fault. Drag folding
6624-513: The fault plane and a vertical plane that strikes parallel to the fault. Ring faults , also known as caldera faults , are faults that occur within collapsed volcanic calderas and the sites of bolide strikes, such as the Chesapeake Bay impact crater . Ring faults are the result of a series of overlapping normal faults, forming a circular outline. Fractures created by ring faults may be filled by ring dikes . Synthetic and antithetic are terms used to describe minor faults associated with
6720-401: The fault plane, the horizontal extensional displacement on a listric fault implies a geometric "gap" between the hanging and footwalls of the fault forms when the slip motion occurs. To accommodate into the geometric gap, and depending on its rheology , the hanging wall might fold and slide downwards into the gap and produce rollover folding , or break into further faults and blocks which fil in
6816-427: The fault-bend fold diagram. Thrust faults form nappes and klippen in the large thrust belts. Subduction zones are a special class of thrusts that form the largest faults on Earth and give rise to the largest earthquakes. A fault which has a component of dip-slip and a component of strike-slip is termed an oblique-slip fault . Nearly all faults have some component of both dip-slip and strike-slip; hence, defining
6912-562: The first American inhabitants sailed from Beringia some 13,000 years ago, with widespread habitation of the Americas during the end of the Last Glacial Period , in what is known as the Late Glacial Maximum , around 12,500 years ago. The oldest petroglyphs in North America date from 15,000 to 10,000 years before present. Genetic research and anthropology indicate additional waves of migration from Asia via
7008-475: The gap. If faults form, imbrication fans or domino faulting may form. A reverse fault is the opposite of a normal fault—the hanging wall moves up relative to the footwall. Reverse faults indicate compressive shortening of the crust. A thrust fault has the same sense of motion as a reverse fault, but with the dip of the fault plane at less than 45°. Thrust faults typically form ramps, flats and fault-bend (hanging wall and footwall) folds. A section of
7104-847: The geographic center of either the 50 states, the conterminous United States, or the North American continent." Nonetheless, there is a 4.6-meter (15 ft) field stone obelisk in Rugby claiming to mark the center. The North American continental pole of inaccessibility is located 1,650 km (1,030 mi) from the nearest coastline, between Allen and Kyle, South Dakota at 43°22′N 101°58′W / 43.36°N 101.97°W / 43.36; -101.97 ( Pole of Inaccessibility North America ) . Canada can be divided into roughly seven physiographic divisions: The lower 48 U.S. states can be divided into roughly eight physiographic divisions: Mexico can be divided into roughly fifteen physiographic divisions: North America
7200-419: The indigenous people who lived there, including the bison hunters of the Great Plains and the farmers of Mesoamerica . Native groups also are classified by their language families , which included Athapascan and Uto-Aztecan languages. Indigenous peoples with similar languages did not always share the same material culture , however, and were not necessarily always allies. Anthropologists speculate that
7296-468: The land since its creation, but there is no evidence that humans evolved there. The specifics of the initial settlement of the Americas by ancient Asians are subject to ongoing research and discussion. The traditional theory has been that hunters entered the Bering Land Bridge between eastern Siberia and present-day Alaska from 27,000 to 14,000 years ago. A growing viewpoint is that
7392-657: The mainland in Mexico. With local indigenous allies, the Spanish conquered the Aztec empire in central Mexico in 1521. Spain then established permanent cities in Mexico, Central America, and Spanish South America in the sixteenth century. Once Spaniards conquered the high civilization of the Aztecs and Incas, the Caribbean was a backwater of the Spanish empire. Other European powers began to intrude on areas claimed by Spain, including
7488-927: The middle into the main range of the Rockies and the coast ranges in California , Oregon , Washington , and British Columbia , with the Great Basin—a lower area containing smaller ranges and low-lying deserts—in between. The highest peak is Denali in Alaska. The U.S. Geographical Survey (USGS) states that the geographic center of North America is "6 miles [10 km] west of Balta, Pierce County, North Dakota " at about 48°10′N 100°10′W / 48.167°N 100.167°W / 48.167; -100.167 , about 24 kilometers (15 mi) from Rugby, North Dakota . The USGS further states that "No marked or monumented point has been established by any government agency as
7584-454: The name America to North America. In 1538, Gerardus Mercator used the term America on his world map of the entire Western Hemisphere . On his subsequent 1569 map , Mercator called North America "America or New India" ( America sive India Nova ). The Spanish Empire called its territories in North and South America "Las Indias", and the name given to the state body that oversaw the region
7680-493: The northernmost countries and territories of North America: the U.S., Bermuda , Canada, Greenland, and St. Pierre and Miquelon. Although the term does not refer to a unified region, Middle America includes Mexico, Central America, and the Caribbean. North America's largest countries by land area are Canada and the U.S., both of which have well-defined and recognized subregions. In Canada, these include (from east to west) Atlantic Canada , Central Canada , Canadian Prairies ,
7776-440: The northernmost extent of the island named Newfoundland , has provided unmistakable evidence of Norse settlement. Norse explorer Leif Erikson (c. 970–1020 CE) is thought to have visited the area. Erikson was the first European to make landfall on the continent (excluding Greenland). The Mayan culture was still present in southern Mexico and Guatemala when the Spanish conquistadors arrived, but political dominance in
7872-677: The ocean it replaced. The closure of Iapetus involved a complex and protracted collisional history of numerous continental fragments , volcanic arcs and back-arc basins that were accreted to Laurentia and Avalonia between the Early Ordovician and Late Silurian . The notion of a single suture zone in a complex orogen such as the Appalachian/Caledonian is unrealistic as several temporal and spatial distinct suture zones are present. The Early Ordovician (Taconic) Baie Verte Line in Quebec and Newfoundland marks
7968-500: The original movement (fault inversion). In such a way, a normal fault may therefore become a reverse fault and vice versa. In a normal fault, the hanging wall moves downward, relative to the footwall. The dip of most normal faults is at least 60 degrees but some normal faults dip at less than 45 degrees. A downthrown block between two normal faults dipping towards each other is a graben . A block stranded between two grabens, and therefore two normal faults dipping away from each other,
8064-605: The raised but relatively flat plateau of the Canadian Shield in the northeast; and the varied eastern region, which includes the Appalachian Mountains, the coastal plain along the Atlantic seaboard, and the Florida peninsula. Mexico, with its long plateaus and cordilleras , falls largely in the western region, although the eastern coastal plain does extend south along the Gulf. The western mountains are split in
8160-500: The region, and as such rainforest , monsoon , and savanna types can be found, with rains and high temperatures throughout the year. Notable North American fauna include the bison , black bear , jaguar , cougar , prairie dog , turkey , pronghorn , raccoon , coyote , and monarch butterfly . Notable plants that were domesticated in North America include tobacco , maize , squash , tomato , sunflower , blueberry , avocado , cotton , chile pepper , and vanilla . Laurentia
8256-487: The results of the formation of Pangaea was the Appalachian Mountains , which formed some 480 mya, making it among the oldest mountain ranges in the world. When Pangaea began to rift around 200 mya, North America became part of Laurasia , before it separated from Eurasia as its own continent during the mid- Cretaceous period. The Rockies and other western mountain ranges began forming around this time from
8352-412: The right time for—and type of— igneous differentiation . At a given time differentiated magmas would burst violently out of the fault-traps and head to shallower places in the crust where porphyry copper deposits would be formed. As faults are zones of weakness, they facilitate the interaction of water with the surrounding rock and enhance chemical weathering . The enhanced chemical weathering increases
8448-597: The size of the weathered zone and hence creates more space for groundwater . Fault zones act as aquifers and also assist groundwater transport. North America North America is a continent in the Northern and Western Hemispheres . North America is bordered to the north by the Arctic Ocean , to the east by the Atlantic Ocean , to the southeast by South America and the Caribbean Sea , and to
8544-576: The southwest coast of Isle of Man . The fault is manifested by two major rock groups which abut each other, both deposited by their respective, aforementioned continents – the Manx Group to the south-east and the Dalby Group to the north-west. The Niarbyl fault is evidence of two paleocontinents colliding: Avalonia on which present-day England is located and Laurentia which contains both present-day North America and Scotland . The fault
8640-468: The term is also used for the zone of crushed rock along a single fault. Prolonged motion along closely spaced faults can blur the distinction, as the rock between the faults is converted to fault-bound lenses of rock and then progressively crushed. Due to friction and the rigidity of the constituent rocks, the two sides of a fault cannot always glide or flow past each other easily, and so occasionally all movement stops. The regions of higher friction along
8736-587: The terminal Iapetan suture in Newfoundland as it marks the Early Silurian (Salinic) collisional zone between Ganderia and Laurentia. The suture runs through the north-eastern states of Maine, New Hampshire, Massachusetts and Connecticut. Rhode Island lies entirely to the east of the suture. The estuary of the River Shannon (Ireland's largest river) follows the line of the Iapetus suture on
8832-627: The west and south by the Pacific Ocean . The region includes the Bahamas , Bermuda , Canada , the Caribbean , Central America , Clipperton Island , Greenland , Mexico , Saint Pierre and Miquelon , Turks and Caicos Islands , and the United States . North America covers an area of about 24,709,000 square kilometers (9,540,000 square miles), representing approximately 16.5% of the Earth 's land area and 4.8% of its total surface area. It
8928-547: The west coast. The suture reaches the east coast at Clogherhead in County Louth . Ireland's crust (and sedimentary rocks) to the north-west of the suture originally derives from Laurentia (proto-North America), while the crust to the south-east is Avalonian ("European"). The Niarbyl Fault is an exposed section of the Iapetus Suture as it crosses through the Irish Sea . It is readily visible in present-day Niarbyl on
9024-549: Was called the Council of the Indies . The United Nations and its statistics division recognize North America as including three regions: Northern America, Central America , and the Caribbean . "Northern America" is a distinct term from "North America", excluding Central America, which itself may or may not include Mexico . In the limited context of regional trade agreements, the term is used to reference three nations: Canada,
9120-817: Was in Jamestown, Virginia in 1607, followed by additional colonial establishments on the east coast from present-day Georgia in the south to Massachusetts in the north, forming the Thirteen Colonies of British America. The English did not establish settlements north or east of the St. Lawrence Valley in present-day Canada until after the conclusion of the American Revolutionary War . Britain's early settlements in present-day Canada included St. John's, Newfoundland in 1630 and Halifax, Nova Scotia in 1749. The first permanent French settlement
9216-473: Was the first European to suggest that the Americas represented a landmass not then known to the Europeans. In 1507, Waldseemüller published a world map, and placed the word "America" on the continent of present-day South America. The continent north of present-day Mexico was then referred to as Parias. On a 1553 world map published by Petrus Apianus , North America was called "Baccalearum", meaning "realm of
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