193-629: The Canadian Arctic Rift System is a major North American geological structure extending from the Labrador Sea in the southeast through Davis Strait , Baffin Bay and the Arctic Archipelago in the northwest. It consists of a series of interconnected rifts that formed during the Paleozoic , Mesozoic and Cenozoic eras. Extensional stresses along the entire length of the rift system have resulted in
386-550: 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
579-710: A climate similar to the Pacific Northwest . On the Alaska North Slope , Metasequoia was the dominant conifer. Much of the diversity represented migrants from nearer the equator. Deciduousness was dominant, probably to conserve energy by retroactively shedding leaves and retaining some energy rather than having them die from frostbite. In south-central Alaska, the Chickaloon Formation preserves peat-forming swamps dominated by taxodiaceous conifers and clastic floodplains occupied by angiosperm–conifer forests. At
772-530: A defined deep-water thermocline (a warmer mass of water closer to the surface sitting on top of a colder mass nearer the bottom) persisting throughout the epoch. The Atlantic foraminifera indicate a general warming of sea surface temperature–with tropical taxa present in higher latitude areas–until the Late Paleocene when the thermocline became steeper and tropical foraminifera retreated back to lower latitudes. Early Paleocene atmospheric CO 2 levels at what
965-597: A depth of about 1,000 m (3,300 ft). The Danian deposits are sequestered into the Aitzgorri Limestone Formation , and the Selandian and early Thanetian into the Itzurun Formation . The Itzurun Formation is divided into groups A and B corresponding to the two stages respectively. The two stages were ratified in 2008, and this area was chosen because of its completion, low risk of erosion, proximity to
1158-529: A floral and faunal turnover of species, with previously abundant species being replaced by previously uncommon ones. In the Paleocene, with a global average temperature of about 24–25 °C (75–77 °F), compared to 14 °C (57 °F) in more recent times, the Earth had a greenhouse climate without permanent ice sheets at the poles, like the preceding Mesozoic . As such, there were forests worldwide—including at
1351-574: A half-graben of the Parry Submarine Rift Valley bounded on the north by high-angle normal faults. Non-marine Tertiary sediments up to approximately 1,100 m (3,600 ft) thick exist in the Barrow Basin. Lady Franklin Basin is one of the deepest basins offshore West Greenland . It was established during Early Cretaceous rifting and lies within a fault zone delimiting the northern end of
1544-643: A higher rate than deciduous angiosperms as deciduous plants can become dormant in harsh conditions. In the Gulf Coast, angiosperms experienced another extinction event during the PETM, which they recovered quickly from in the Eocene through immigration from the Caribbean and Europe. During this time, the climate became warmer and wetter, and it is possible that angiosperms evolved to become stenotopic by this time, able to inhabit
1737-508: A narrow coastal strip between Cape Dyer and Cape Searle . They have a total thickness of over 200 m (660 ft) and are bounded in the north by minor intrusions. The volcanic suite in West Greenland consists mainly of lava flows and occurs on Disko Island , Illorsuit Island and the Nunavik and Nuussuaq peninsulas. A central volcano formed on Illorsuit Island with the emplacement of
1930-441: A narrow range of temperature and moisture; or, since the dominant floral ecosystem was a highly integrated and complex closed-canopy rainforest by the middle Paleocene, the plant ecosystems were more vulnerable to climate change . There is some evidence that, in the Gulf Coast, there was an extinction event in the late Paleocene preceding the PETM, which may have been due to the aforementioned vulnerability of complex rainforests, and
2123-648: 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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#17328515448132316-564: A period of regional uplift and compression brought on by the Eurekan Rifting Episode. The South Cape Fault Zone to the northeast is a major east–west trending fault extending throughout much of the length of Jones Sound . It cuts across the peninsulas of southern Ellesmere Island. Extending several hundred kilometres through Crozier Strait is the Crozier Strait Fault Zone. It lies within a north-trending anticline of
2509-571: 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 ,
2702-458: A regional stress field associated with post-glacial rebound . The area between Greenland and Baffin Island is one of the most seismically active regions in eastern Canada. It was not known as a seismic zone until November 20, 1933, when an earthquake with a surface-wave magnitude of 7.3 occurred beneath Baffin Bay. This is the largest instrumentally recorded earthquake to have occurred along
2895-546: A role in the occurrence of this earthquake. Earthquakes of magnitude 6.0 or greater have since been recorded in 1934, 1945, 1947 and 1957. A linear belt of medium- amplitude earthquakes known as the Labrador Sea Seismic Zone is coincident with the extinct spreading axis of the Mid-Labrador Ridge . Earthquakes as large as magnitude 5.0 have been recorded along this zone since 1982. The Ungava Fault Zone
3088-424: A short time frame. The freezing temperatures probably reversed after three years and returned to normal within decades, sulfuric acid aerosols causing acid rain probably dissipated after 10 years, and dust from the impact blocking out sunlight and inhibiting photosynthesis would have lasted up to a year though potential global wildfires raging for several years would have released more particulates into
3281-694: A single formation (a stratotype ) identifying the lower boundary of the stage. In 1989, the ICS decided to split the Paleocene into three stages: the Danian, Selandian, and Thanetian. The Danian was first defined in 1847 by German-Swiss geologist Pierre Jean Édouard Desor based on the Danish chalks at Stevns Klint and Faxse , and was part of the Cretaceous, succeeded by the Tertiary Montian Stage. In 1982, after it
3474-520: A southern branch of the Lancaster Aulacogen between Baffin Island and Somerset Island. It is a deep waterbody measuring 64 km (40 mi) wide at its northern end and over 105 km (65 mi) at its southern end. The inlet connects Lancaster Sound in the north with the Gulf of Boothia in the south. Davis Strait is a narrow and relatively shallow area connecting Baffin Bay in the north with
3667-562: A variety of tectonic features, including grabens , half-grabens , basins and faults . Development of the Canadian Arctic Rift System was accompanied by two plate tectonic episodes that originated on opposite sides of the North American plate and were propagated toward each other. Both were strongly controlled by pre-existing structures, which either guided the propagating faults or impeded their growth. The rift system
3860-540: 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
4053-640: A width of up to 400 km (250 mi) , encompassing an area of 313,000 km (121,000 sq mi) . Baffin Basin is a north-northwest trending geologic structure underlying much of central Baffin Bay. It formed as a result of seafloor spreading during the Tertiary opening of Baffin Bay around 56 million years ago. The northern extent of the basin is bounded by the Jones Sound, Lancaster Sound and Nares Strait aquatic sills 150 to 200 m (490 to 660 ft) below sea level while its southern extent
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#17328515448134246-433: A width varying from about 47 to 116 km (29 to 72 mi) . Surface data and the existence of corresponding seaward-dropping fault blocks on the north coast of Devon Island and on the south coast of Ellesmere Island suggest that Jones Sound may be a graben structure. Baffin Bay is a 1,200 km (750 mi) long and 500 km (310 mi) wide semi-enclosed sea surrounded by Ellesmere Island and Devin Island in
4439-605: Is a branch of that ridge. A characteristic feature of the Labrador Basin is the Northwest Atlantic Mid-Ocean Channel . This is a 100-to-150-metre-deep (330 to 490 ft) turbidity current system of channels that extend southward along the axis of the basin and then into the Newfoundland Basin. Situated on Bylot Island and northern Baffin Island are a series of grabens and horsts that constitute
4632-607: Is a combination of the Ancient Greek παλαιός palaiós meaning "old" and the Eocene Epoch (which succeeds the Paleocene), translating to "the old part of the Eocene". The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event , brought on by an asteroid impact ( Chicxulub impact ) and possibly volcanism ( Deccan Traps ), marked the beginning of the Paleocene and killed off 75% of species, most famously
4825-690: Is a major seaway system connecting the Atlantic and Arctic oceans. This system was created by geological events of the Canadian Arctic Rift System and is still controlled by rift structures. It includes the Northwest Passage , which cuts through the Labrador Sea, Baffin Bay, Parry Channel and other channels within and adjacent to the Arctic Archipelago. Inflow from the Atlantic Ocean and outflow from
5018-451: Is a major tectonic feature of Davis Strait separating the failed Labrador Sea and Baffin Bay spreading centres. It was associated with leaky transform motion related to the northward motion of Greenland relative to mainland North America during the Paleogene . The fault zone has a length of roughly 1,000 km (620 mi) and an elongate north-northeast trend. A northern extension called
5211-506: Is a northeast trending structure that extends along the continental margin northwest of the Queen Elizabeth Islands. It forms a boundary between the Canadian Arctic Rift System and other rifted structures to the northwest. The Kaltag acted as a transform fault with intermittent pulses of both extension and strike-slip displacement during three time intervals. Tectonism during the first time interval from Carboniferous to Permian
5404-640: 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
5597-462: Is a waterway in the Arctic Archipelago formed by the Parry Submarine Rift Valley. It consists of four waterbodies: Lancaster Sound, M'Clure Strait , Viscount Melville Sound and Barrow Strait . With a length of over 1,100 km (680 mi) , Parry Channel connects Baffin Bay in the east with Beaufort Sea in the west. The north and south sides of the channel are opened by a number of smaller waterways. Of these, Admiralty Inlet penetrates deep into
5790-437: Is also evidence this occurred again 300,000 years later in the early Thanetian dubbed MPBE-2. Respectively, about 83 and 132 gigatons of methane-derived carbon were ejected into the atmosphere, which suggests a 2–3 °C (3.6–5.4 °F) rise in temperature, and likely caused heightened seasonality and less stable environmental conditions. It may have also caused an increase of grass in some areas. From 59.7 to 58.1 Ma, during
5983-511: 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
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6176-920: 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 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
6369-537: Is controversial, but most likely about 2,500 years. This carbon also interfered with the carbon cycle and caused ocean acidification, and potentially altered and slowed down ocean currents, the latter leading to the expansion of oxygen minimum zones (OMZs) in the deep sea. In surface water, OMZs could have also been caused from the formation of strong thermoclines preventing oxygen inflow, and higher temperatures equated to higher productivity leading to higher oxygen usurpation. Further, expanding OMZs could have caused
6562-472: Is delimited by the Davis Strait aquatic sill roughly 600 m (2,000 ft) below sea level. Lancaster Basin is a half-graben forming the eastern mouth of the larger Parry Submarine Rift Valley. It contains several block faulted structures and is filled with Mesozoic, Tertiary and Quaternary sediments. Barrow Basin is a prominent topographic depression and, like Lancaster Basin to the east, represents
6755-535: 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
6948-584: 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
7141-435: Is now Castle Rock , Colorado, were calculated to be between 352 and 1,110 parts per million (ppm), with a median of 616 ppm. Based on this and estimated plant-gas exchange rates and global surface temperatures, the climate sensitivity was calculated to be +3 °C when CO 2 levels doubled, compared to 7 °C following the formation of ice at the poles. CO 2 levels alone may have been insufficient in maintaining
7334-662: Is now a nearly inactive structure and that the entire system is travelling as a part of the North American plate. Several earthquakes occur but their patterns indicate that tectonic forces characteristic of plate margins are not acting directly within the Canadian Arctic today. As a result, there are questions as to whether the Greenland plate should still be considered a separate plate. The present seismic activity may be mainly an expression of readjustment of existing rift structures to
7527-536: Is now inactive apart from minor adjustments that are indicated by occasional earthquakes in Baffin Bay and the Labrador Sea. The Canadian Arctic Rift System is a branch of the Mid-Atlantic Ridge that extends 4,800 km (3,000 mi) into the North American continent. It is an incipient structure that diminishes in degree of development northwestward, bifurcates at the head of Baffin Bay and disappears into
7720-548: Is now the Mediterranean Sea tropical. South-central North America had a humid, monsoonal climate along its coastal plain, but conditions were drier to the west and at higher altitudes. Svalbard was temperate, having a mean temperature of 19.2 ± 2.49 °C during its warmest month and 1.7 ± 3.24 °С during its coldest. Global deep water temperatures in the Paleocene likely ranged from 8–12 °C (46–54 °F), compared to 0–3 °C (32–37 °F) in modern day. Based on
7913-488: 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
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8106-576: Is referred to as the Boreal Rifting Episode which followed compression and exposure brought on by the Ellesmerian orogeny . The second is referred to as the Eurekan Rifting Episode and created most of the structures that comprise the Canadian Arctic Rift System. Both rifting episodes were active simultaneously from the Early Cretaceous to mid- Tertiary . The Boreal Rifting Episode began in
8299-686: 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
8492-516: 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
8685-544: Is why the GSSP was moved to Zumaia. Today, the beginning of the Selandian is marked by the appearances of the nannofossils Fasciculithus tympaniformis , Neochiastozygus perfectus , and Chiasmolithus edentulus , though some foraminifera are used by various authors. The Thanetian was first proposed by Swiss geologist Eugène Renevier , in 1873; he included the south England Thanet , Woolwich , and Reading formations. In 1880, French geologist Gustave Frédéric Dollfus narrowed
8878-705: The Americas at least 20,000 years ago, but various evidence points to possibly earlier dates. The Paleo-Indian period in North America followed 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,
9071-777: The Antarctic Peninsula . In the Paleocene, the waterways between the Arctic Ocean and the North Atlantic were somewhat restricted, so North Atlantic Deep Water (NADW) and the Atlantic Meridional Overturning Circulation (AMOC)—which circulates cold water from the Arctic towards the equator—had not yet formed, and so deep water formation probably did not occur in the North Atlantic. The Arctic and Atlantic would not be connected by sufficiently deep waters until
9264-410: The Atlantic Ocean then propagated northwest where the Labrador Sea started opening in the Late Cretaceous . Seafloor spreading commenced in the southern Labrador Sea 75–60 million years ago, during which time Greenland moved north relative to mainland North America. This northward movement gave rise to compressive forces between northern Greenland and the Arctic Archipelago, setting the stage for
9457-432: 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
9650-399: 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
9843-477: The Caribbean Plate ), which had formed from the Galápagos hotspot in the Pacific in the latest Cretaceous, was moving eastward as the North American and South American plates were getting pushed in the opposite direction due to the opening of the Atlantic ( strike-slip tectonics ). This motion would eventually uplift the Isthmus of Panama by 2.6 mya. The Caribbean Plate continued moving until about 50 mya when it reached its current position. The components of
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#173285154481310036-429: 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 ;
10229-440: 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
10422-409: The Cretaceous Period and the Mesozoic Era , and initiated the Cenozoic Era and the Paleogene Period. It is divided into three ages : the Danian spanning 66 to 61.6 million years ago (mya), the Selandian spanning 61.6 to 59.2 mya, and the Thanetian spanning 59.2 to 56 mya. It is succeeded by the Eocene. The K–Pg boundary is clearly defined in the fossil record in numerous places around
10615-451: The Earth 's land area and 4.8% of its total surface area. It 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,
10808-407: 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)
11001-406: The Eurekan orogeny . Seafloor spreading reached the northern Labrador Sea 60–40 million years ago and Greenland moved simultaneously past Ellesmere Island along the Nares Strait . Approximately 170 km (110 mi) of Paleocene separation occurred between Greenland and Baffin Island , producing oceanic crust within Baffin Bay. With the commencement of active seafloor spreading in
11194-422: The Holarctic region (comprising most of the Northern Hemisphere) was mainly early members of Ginkgo , Metasequoia , Glyptostrobus , Macginitiea , Platanus , Carya , Ampelopsis , and Cercidiphyllum . Patterns in plant recovery varied significantly with latitude , climate, and altitude. For example, what is now Castle Rock, Colorado featured a rich rainforest only 1.4 million years after
11387-466: 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
11580-442: The Late Devonian and emanated southeastward from the Canada Basin into the North American continent. It caused uplift of the Pearya Geanticline and Sverdrup Rim, as well as crustal extension that led to thinning and subsidence of the regional lithosphere . The rifting extended only into the area that would be occupied by the future central Queen Elizabeth Islands and was aborted there due to interfering structural trends. In
11773-478: 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
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#173285154481311966-501: The Norwegian Sea during the Early Eocene , the direction of seafloor spreading changed in both the Labrador Sea and Baffin Bay. Continued spreading in the Norwegian Sea eventually separated Greenland from Eurasia , resulting in the creation of the Greenland plate and the South Greenland triple junction . By this time spreading within Baffin Bay and the Labrador Sea had slowed and became oblique, eventually ceasing between 45 and 36 million years ago. The final phase of rifting
12159-422: The Paleocene–Eocene thermal maximum , a short period of intense warming and ocean acidification brought about by the release of carbon en masse into the atmosphere and ocean systems, which led to a mass extinction of 30–50% of benthic foraminifera –planktonic species which are used as bioindicators of the health of a marine ecosystem—one of the largest in the Cenozoic. This event happened around 55.8 mya, and
12352-409: The Quaternary from the Tertiary in 1829; and Scottish geologist Charles Lyell (ignoring the Quaternary) had divided the Tertiary Epoch into the Eocene , Miocene , Pliocene , and New Pliocene ( Holocene ) Periods in 1833. British geologist John Phillips had proposed the Cenozoic in 1840 in place of the Tertiary, and Austrian paleontologist Moritz Hörnes had introduced the Paleogene for
12545-406: The Transantarctic Mountains . The poles probably had a cool temperate climate; northern Antarctica, Australia, the southern tip of South America, what is now the US and Canada, eastern Siberia, and Europe warm temperate; middle South America, southern and northern Africa, South India, Middle America, and China arid; and northern South America, central Africa, North India, middle Siberia, and what
12738-420: 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
12931-485: The opening of the North Atlantic Ocean and seafloor spreading , the divergence of the Greenland Plate from the North American Plate , and, climatically, the PETM by dissociating methane clathrate crystals on the seafloor resulting in the mass release of carbon. North and South America remained separated by the Central American Seaway , though an island arc (the South Central American Arc) had already formed about 73 mya. The Caribbean Large Igneous Province (now
13124-418: The passive margin of North America and possibly the largest passive-margin earthquake worldwide. Coincidentally, it is also the largest north of the Arctic Circle . In spite of its size, the 1933 Baffin Bay earthquake did not result in any damage due to its offshore location combined with the sparse population of the adjacent onshore areas. Analysis of seismograms indicate that strike-slip faulting played
13317-429: The water column . Though the temperature in the latest Danian varied at about the same magnitude, this event coincides with an increase of carbon. About 60.5 mya at the Danian/Selandian boundary, there is evidence of anoxia spreading out into coastal waters, and a drop in sea levels which is most likely explained as an increase in temperature and evaporation, as there was no ice at the poles to lock up water. During
13510-399: The Østerrende Clay . The beginning of this stage was defined by the end of carbonate rock deposition from an open ocean environment in the North Sea region (which had been going on for the previous 40 million years). The Selandian deposits in this area are directly overlain by the Eocene Fur Formation —the Thanetian was not represented here—and this discontinuity in the deposition record
13703-401: 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
13896-686: The Americas had not yet joined, the Indian Plate had begun its collision with Asia, and the North Atlantic Igneous Province was forming in the third-largest magmatic event of the last 150 million years. In the oceans, the thermohaline circulation probably was much different from what it is today, with downwellings occurring in the North Pacific rather than the North Atlantic, and water density mainly being controlled by salinity rather than temperature. The K–Pg extinction event caused
14089-639: The Arctic Archipelago. Several episodes of intrusive and extrusive activity took place from the Paleozoic to Cenozoic with the emplacement of dikes , sills , lava flows and pyroclastic rocks . The Sverdrup Basin Magmatic Province in the east-central Sverdrup Basin is an Early Cretaceous to Paleogene large igneous province . It consists of pyroclastic deposits, thin lava flows, flood basalts and central volcanoes , as well as hypabyssal sills and dikes. Argon–argon dating of mafic igneous rocks from
14282-548: The Arctic Archipelago. The rift system is mainly an extensional structure, which has allowed Greenland and Canada to rotate apart and form intervening seaways. The segment extending from the Labrador Sea to Baffin Bay is sometimes referred to as the Labrador Sea–Baffin Bay rift system or the North Atlantic–Labrador Sea rift system. Two rifting episodes created the Canadian Arctic Rift System. The first
14475-571: The Arctic Ocean has resulted in ocean currents flowing along the rifted continental margins of West Greenland, Baffin Island and Labrador. Nares Strait lies within the Nares Submarine Rift Valley between North Greenland and Ellesmere Island. It is a north-northeast trending channel connecting Baffin Bay in the south with the Arctic Ocean in the north. From south to north, the strait includes Smith Sound , Kane Basin , Kennedy Channel , Hall Basin and Robeson Channel . Parry Channel
14668-566: 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
14861-437: The Atlantic Ocean. Crozier Strait between Bathurst Island and Little Cornwallis Island dominates the Crozier Strait Fault Zone. It is a narrow but extremely deep body of water measuring roughly 30 km (19 mi) long and 8 km (5.0 mi) wide at its narrowest point. The strait, an arm of the Arctic Ocean, connects Queens Channel in the north with McDougall Sound in the south. Prince Regent Inlet occupies
15054-492: The Baffin Island Current flows south along the length of western Baffin Bay and the western half of Davis Strait. It then divides at Hudson Strait; one branch sets westward along the northern half of Hudson Strait; another branch continues southward towards the Labrador Sea. Labrador Current is a continuation of the West Greenland and Baffin Island currents. It flows down the west side of the Labrador Sea then back into
15247-526: 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
15440-668: 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
15633-571: The Cornwallis Fold Belt and appears to contain a lowered fault block . Bathymetric data suggest it is a possible graben structure with steep, linear, north–south margins that formed during the Eurekan Rifting Episode. The faults forming the supposed graben appear to have been guided in part by the structure of the Cornwallis Fold Belt, but probably were controlled ultimately by trends in the Precambrian crystalline basement . The Kaltag Fault
15826-448: The Cretaceous, had receded. Between about 60.5 and 54.5 mya, there was heightened volcanic activity in the North Atlantic region—the third largest magmatic event in the last 150 million years—creating the North Atlantic Igneous Province . The proto- Iceland hotspot is sometimes cited as being responsible for the initial volcanism, though rifting and resulting volcanism have also contributed. This volcanism may have contributed to
16019-439: The Cretaceous, tropical or subtropical , and the poles were temperate , with an average global temperature of roughly 24–25 °C (75–77 °F). For comparison, the average global temperature for the period between 1951 and 1980 was 14 °C (57 °F). The latitudinal temperature gradient was approximately 0.24 °C per degree of latitude. The poles also lacked ice caps, though some alpine glaciation did occur in
16212-615: The Eocene and Neogene for the Miocene and Pliocene in 1853. After decades of inconsistent usage, the newly formed International Commission on Stratigraphy (ICS), in 1969, standardized stratigraphy based on the prevailing opinions in Europe: the Cenozoic Era subdivided into the Tertiary and Quaternary sub-eras, and the Tertiary subdivided into the Paleogene and Neogene Periods. In 1978, the Paleogene
16405-470: The Eocene". The Eocene, in turn, is derived from Ancient Greek eo— eos ἠώς meaning "dawn", and—cene kainos καινός meaning "new" or "recent", as the epoch saw the dawn of recent, or modern, life. Paleocene did not come into broad usage until around 1920. In North America and mainland Europe, the standard spelling is "Paleocene", whereas it is "Palaeocene" in the UK. Geologist T. C. R. Pulvertaft has argued that
16598-612: The Freemans Cove area of Bathurst Island. It is confined to the Southeast Bathurst Fault Zone, consisting of sills, dikes, agglomeratic vents and small plugs . Most of the suite consists of nephelinite or larnite - normative nephelinites and basanites , with rarer olivine melilite nephelinite, phonolite and tholeiitic and alkali basalt rocks. Extensive erosion has removed all traces of lava flows but lava fragments, bombs and scoria occur as clasts within
16791-538: The Ikermiut Fault Zone is dominated by Late Paleocene to Early Eocene thrust faults due to strike-slip movements between the Greenland and North American plates. Situated on Bathurst Island is the Southeast Bathurst Fault Zone , a north–south trending system of normal faults that form a graben-like structure. It originally formed during the Boreal Rifting Episode, but was reactivated during
16984-620: The Kaltag Fault was the northwestern boundary of the Queen Elizabeth Islands Subplate. Trending along the north side of Lancaster Sound is a major steeply dipping normal fault called the Parry Channel Fault. As much as 8 km (5.0 mi) of vertical displacement took place along this fault during the Eurekan Rifting Episode. The Northern Baffin and Admiralty faults trend along the south side of Lancaster Sound,
17177-692: The K–Pg boundary, the largest the Mexican Chicxulub crater whose impact was a major precipitator of the K–Pg extinction, and also the Ukrainian Boltysh crater , dated to 65.4 mya the Canadian Eagle Butte crater (though it may be younger), the Vista Alegre crater (though this may date to about 115 mya ). Silicate glass spherules along the Atlantic coast of the U.S. indicate a meteor impact in
17370-543: The Labrador Sea in the south. It varies in width from 300 km (190 mi) to over 950 km (590 mi) , with the shallowest waters found along the Davis Sill. This aquatic sill is a submarine ridge 350 to 550 m (1,150 to 1,800 ft) below sea level extending from Baffin Island in the west to Greenland in the east. Unlike Baffin Bay and the Labrador Sea, Davis Strait is bounded by volcanic passive margins . Paleogene volcanic rocks are exposed on both sides of
17563-600: The Labrador Sea. A thick succession of Cretaceous and Cenozoic sediments occupies the Lady Franklin Basin. Labrador Basin is an immense structural trough between Greenland and Labrador that formed as a result of seafloor spreading from the Late Cretaceous to the Late Eocene . Its seabed consists of a slightly southeast trending plain that ranges 3,000 to 4,500 m (9,800 to 14,800 ft) below sea level. In
17756-494: The Labrador Sea. They form sub-basins that are controlled by steeply-dipping normal faults, which predominately dip toward the north. West Greenland Current originates from the movement of Atlantic water flowing around the southern point of Greenland caused by the East Greenland and Irminger currents. It transports freshwater into the Labrador Sea, influencing the formation of Labrador Sea Water. The current flows north along
17949-472: The Late Cretaceous became dominant trees in Patagonia, before going extinct. Some plant communities, such as those in eastern North America, were already experiencing an extinction event in the late Maastrichtian, particularly in the 1 million years before the K–Pg extinction event. The "disaster plants" that refilled the emptied landscape crowded out many Cretaceous plants, and resultantly, many went extinct by
18142-520: The Miocene about 24–17 mya. There is evidence that some plants and animals could migrate between India and Asia during the Paleocene, possibly via intermediary island arcs. In the modern thermohaline circulation , warm tropical water becomes colder and saltier at the poles and sinks ( downwelling or deep water formation) that occurs at the North Atlantic near the North Pole and the Southern Ocean near
18335-419: 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
18528-730: The North Atlantic Ocean where it continues southward along the east coast of Newfoundland and completely floods the northeastern part of the Grand Banks . Here it divides; one branch sets southwestward along the Avalon Peninsula while another and usually major branch continues southward down the east side of the Grand Banks. North America North America is a continent in the Northern and Western Hemispheres . North America
18721-567: The North Baffin Rift Zone. These structures formed intermittently from late Proterozoic to early Tertiary time, with the latest period of reactivation having taken place during the Eurekan Rifting Episode. Like many rifts worldwide, the Canadian Arctic Rift System was a site of magmatic activity during active tectonism. This activity was associated with seafloor spreading in the Baffin and Labrador basins as well as continental rifting within
18914-704: The Northern Component Waters by Greenland in the Eocene—the predecessor of the AMOC—may have caused an intense warming in the North Hemisphere and cooling in the Southern, as well as an increase in deep water temperatures. In the PETM, it is possible deep water formation occurred in saltier tropical waters and moved polewards, which would increase global surface temperatures by warming the poles. Also, Antarctica
19107-412: The Paleocene, especially at the end, in tandem with the increasing global temperature. At the North Pole, woody angiosperms had become the dominant plants, a reversal from the Cretaceous where herbs proliferated. The Iceberg Bay Formation on Ellesmere Island , Nunavut (latitude 75 – 80 ° N) shows remains of a late Paleocene dawn redwood forest, the canopy reaching around 32 m (105 ft), and
19300-613: The Sarqâta qáqâ gabbro - granophyre intrusion roughly 56 million years ago. The Tertiary volcanic rocks of Baffin Island and West Greenland form part of the North Atlantic Igneous Province , which extends roughly 3,000 km (1,900 mi) eastward through East Greenland , Iceland , the Faroe Islands , Ireland and Scotland . This large igneous province has been linked to the Iceland hotspot . Extending through northern North America
19493-519: The South Pole, due to the increasing isolation of Antarctica, many plant taxa were endemic to the continent instead of migrating down. Patagonian flora may have originated in Antarctica. The climate was much cooler than in the Late Cretaceous, though frost probably was not common in at least coastal areas. East Antarctica was likely warm and humid. Because of this, evergreen forests could proliferate as, in
19686-472: 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
19879-734: The Sverdrup Basin Magmatic Province are well-exposed in the Princess Margaret Range , a north–south trending mountain range extending across the length of Axel Heiberg Island . Basaltic lava flows occur in the Isachsen and Strand Fiord formations . Sills intrude the entire Mesozoic succession and are particularly abundant in the Triassic shales of the Blaa Mountain Group. A volcanic suite of Eocene age occurs in
20072-856: The Thanetian is best correlated with the C26r/C26n reversal. Several economically important coal deposits formed during the Paleocene, such as the sub-bituminous Fort Union Formation in the Powder River Basin of Wyoming and Montana, which produces 43% of American coal; the Wilcox Group in Texas, the richest deposits of the Gulf Coastal Plain ; and the Cerrejón mine in Colombia, the largest open-pit mine in
20265-653: The Turgai route connecting Europe with Asia (which were otherwise separated by the Turgai Strait at this time). The Laramide orogeny , which began in the Late Cretaceous, continued to uplift the Rocky Mountains ; it ended at the end of the Paleocene. Because of this and a drop in sea levels resulting from tectonic activity, the Western Interior Seaway , which had divided the continent of North America for much of
20458-522: 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
20651-540: 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
20844-598: The United States, Mexico, and Greenland or, alternatively, Canada, Greenland and 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
21037-550: 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,
21230-575: 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
21423-438: The absence of frost and a low probability of leaves dying, it was more energy efficient to retain leaves than to regrow them every year. One possibility is that the interior of the continent favored deciduous trees, though prevailing continental climates may have produced winters warm enough to support evergreen forests. As in the Cretaceous, podocarpaceous conifers, Nothofagus , and Proteaceae angiosperms were common. In
21616-465: The agglomerates. Erosional remnants of 50-metre-thick (160 ft) sills form the prominent mesas of North Mesa, Peaked Hill and Round Hill, the latter two of which consist of tholeiitic basalt and alkali basalt respectively. A major episode of Tertiary magmatism related to the opening of Baffin Bay emplaced mafic intrusions and volcanic rocks on Baffin Island and in West Greenland. Basaltic breccias and lavas on Baffin Island are exposed mainly along
21809-470: The algae Discoaster and a diversification of Heliolithus , though the best correlation is in terms of paleomagnetism . A chron is the occurrence of a geomagnetic reversal —when the North and South poles switch polarities . Chron 1 (C1n) is defined as modern day to about 780,000 years ago, and the n denotes "normal" as in the polarity of today, and an r "reverse" for the opposite polarity. The beginning of
22002-537: 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
22195-507: The atmosphere. For the following half million years, the carbon isotope gradient—a difference in the C / C ratio between surface and deep ocean water, causing carbon to cycle into the deep sea—may have shut down. This, termed a "Strangelove ocean", indicates low oceanic productivity ; resultant decreased phytoplankton activity may have led to a reduction in cloud seeds and, thus, marine cloud brightening , causing global temperatures to increase by 6 °C ( CLAW hypothesis ). Following
22388-471: The bay the second most important conduit between the Arctic Ocean and the rest of the world's oceans. The Labrador Sea is an arm of the North Atlantic Ocean occupying the Labrador Basin between Greenland and Labrador. It shallows and passes into Davis Strait in the north and is open to the North Atlantic Ocean in the southeast. The sea is flanked by continental shelves with banks less than 200 m (660 ft) deep separated by glacially eroded channels:
22581-585: The boundary; for example, in the Williston Basin of North Dakota, an estimated 1/3 to 3/5 of plant species went extinct. The K–Pg extinction event ushered in a floral turnover; for example, the once commonplace Araucariaceae conifers were almost fully replaced by Podocarpaceae conifers, and the Cheirolepidiaceae , a group of conifers that had dominated during most of the Mesozoic but had become rare during
22774-670: The coast of West Greenland, steadily losing volume through low-velocity westward branching as water is fed into the anticyclonic circulatory system of the Labrador Sea. Just south of Davis Sill, a major westward branching occurs, the remainder of the West Greenland Current continuing across Davis Sill into Baffin Bay where it eventually peters out. Baffin Island Current consists mainly of relatively fresh Arctic waters that enter northern Baffin Bay through Nares Strait, Jones Sound and Lancaster Sound. First detectable off Devon Island,
22967-432: 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
23160-858: 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
23353-410: 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
23546-604: 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
23739-559: The country. Paleocene coal has been mined extensively in Svalbard , Norway, since near the beginning of the 20th century, and late Paleocene and early Eocene coal is widely distributed across the Canadian Arctic Archipelago and northern Siberia. In the North Sea, Paleocene-derived natural gas reserves, when they were discovered, totaled approximately 2.23 trillion m (7.89 trillion ft ), and oil in place 13.54 billion barrels. Important phosphate deposits—predominantly of francolite —near Métlaoui , Tunisia were formed from
23932-514: 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
24125-404: The dark forest floor, and epiphytism where a plant grows on another plant in response to less space on the forest floor. Despite increasing density—which could act as fuel—wildfires decreased in frequency from the Cretaceous to the early Eocene as the atmospheric oxygen levels decreased to modern day levels, though they may have been more intense. There was a major die-off of plant species over
24318-405: The definition to just the Thanet Formation. The Thanetian begins a little after the mid-Paleocene biotic event —a short-lived climatic event caused by an increase in methane —recorded at Itzurun as a dark 1 m (3.3 ft) interval from a reduction of calcium carbonate . At Itzurun, it begins about 29 m (95 ft) above the base of the Selandian, and is marked by the first appearance of
24511-447: 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
24704-411: The early to middle Eocene. There is evidence of deep water formation in the North Pacific to at least a depth of about 2,900 m (9,500 ft). The elevated global deep water temperatures in the Paleocene may have been too warm for thermohaline circulation to be predominately heat driven. It is possible that the greenhouse climate shifted precipitation patterns, such that the Southern Hemisphere
24897-529: The ecosystem may have been disrupted by only a small change in climate. The warm Paleocene climate, much like that of the Cretaceous , allowed for diverse polar forests. Whereas precipitation is a major factor in plant diversity nearer the equator, polar plants had to adapt to varying light availability ( polar nights and midnight suns ) and temperatures. Because of this, plants from both poles independently evolved some similar characteristics, such as broad leaves. Plant diversity at both poles increased throughout
25090-408: 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
25283-403: The event, probably due to a rain shadow effect causing regular monsoon seasons. Conversely, low plant diversity and a lack of specialization in insects in the Colombian Cerrejón Formation , dated to 58 mya, indicates the ecosystem was still recovering from the K–Pg extinction event 7 million years later. Flowering plants ( angiosperms ), which had become dominant among forest taxa by
25476-544: The exploratory voyages of Christopher Columbus led to 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
25669-399: The extreme disruptions in the aftermath of the K-Pg extinction event, the relatively cool, though still greenhouse, conditions of the Late Cretaceous–Early Palaeogene Cool Interval (LKEPCI) that began in the Late Cretaceous continued. The Dan –C2 Event 65.2 mya in the early Danian spanned about 100,000 years, and was characterized by an increase in carbon, particularly in the deep sea. Since
25862-429: The extreme west, in the Banks Island area, extension of the Boreal Rifting Episode continued uninterrupted until the mid-Tertiary. The Eurekan Rifting Episode commenced in the Early Cretaceous as the Boreal Rifting Episode declined. Crustal stretching began at the south end of the rift system 130 million years ago, during which time supercontinent Laurasia was in the process of breaking apart. Rifting began from
26055-421: 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
26248-464: The former of which is dominant. It extends from Admiralty Inlet in the west then trends eastward along the north coasts of Baffin and Bylot islands to Baffin Bay where it possibly connects with other rift structures. The Prince Regent Fault is a major fault that trends along the east coast of Somerset Island. It forms the southwestern boundary of the Lancaster Aulacogen and is west of the inferred Brodeur Peninsula Fault, which presumably trends along
26441-423: The former southern supercontinent Gondwanaland in the Southern Hemisphere continued to drift apart, but Antarctica was still connected to South America and Australia. Africa was heading north towards Europe, and the Indian subcontinent towards Asia, which would eventually close the Tethys Ocean . The Indian and Eurasian Plates began colliding in the Paleocene, with uplift (and a land connection) beginning in
26634-795: 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
26827-453: The greenhouse climate, and some positive feedbacks must have been active, such as some combination of cloud, aerosol, or vegetation related processes. A 2019 study identified changes in orbital eccentricity as the dominant drivers of climate between the late Cretaceous and the early Eocene. The effects of the meteor impact and volcanism 66 mya and the climate across the K–Pg boundary were likely fleeting, and climate reverted to normal in
27020-419: 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
27213-400: 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
27406-410: The late Danian, there was a warming event and evidence of ocean acidification associated with an increase in carbon; at this time, there was major seafloor spreading in the Atlantic and volcanic activity along the southeast margin of Greenland. The Latest Danian Event, also known as the Top Chron C27n Event, lasted about 200,000 years and resulted in a 1.6–2.8 °C increase in temperatures throughout
27599-477: The late Paleocene to the early Eocene. Impact craters formed in the Paleocene include: the Connolly Basin crater in Western Australia less than 60 mya, the Texan Marquez crater 58 mya, the Greenlandic Hiawatha Glacier crater 58 mya, and possibly the Jordan Jabel Waqf as Suwwan crater which dates to between 56 and 37 mya. Vanadium -rich osbornite from the Isle of Skye , Scotland, dating to 60 mya may be impact ejecta . Craters were also formed near
27792-491: The late Selandian and early Thanetian, organic carbon burial resulted in a period of climatic cooling, sea level fall and transient ice growth. This interval saw the highest δ O values of the epoch. The Paleocene–Eocene Thermal Maximum was an approximately 200,000-year-long event where the global average temperature rose by some 5 to 8 °C (9 to 14 °F), and mid-latitude and polar areas may have exceeded modern tropical temperatures of 24–29 °C (75–84 °F). This
27985-432: The latter spelling is incorrect because this would imply either a translation of "old recent" or a derivation from "pala" and "Eocene", which would be incorrect because the prefix palæo- uses the ligature æ instead of "a" and "e" individually, so only both characters or neither should be dropped, not just one. The Paleocene Epoch is the 10 million year time interval directly after the K–Pg extinction event , which ended
28178-444: 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
28371-509: The mid- Maastrichtian , more and more carbon had been sequestered in the deep sea possibly due to a global cooling trend and increased circulation into the deep sea. The Dan–C2 event may represent a release of this carbon after deep sea temperatures rose to a certain threshold, as warmer water can dissolve less carbon. Alternatively, the cause of the Dan-C2 event may have been a pulse of Deccan Traps volcanism. Savanna may have temporarily displaced forestland in this interval. Around 62.2 mya in
28564-421: The mid-Palaeocene biotic event (MPBE), also known as the Early Late Palaeocene Event (ELPE), around 59 Ma (roughly 50,000 years before the Selandian/Thanetian boundary), the temperature spiked probably due to a mass release of the deep sea methane hydrate into the atmosphere and ocean systems. Carbon was probably output for 10–11,000 years, and the aftereffects likely subsided around 52–53,000 years later. There
28757-399: The middle Cretaceous 110–90 mya, continued to develop and proliferate, more so to take advantage of the recently emptied niches and an increase in rainfall. Along with them coevolved the insects that fed on these plants and pollinated them. Predation by insects was especially high during the PETM. Many fruit-bearing plants appeared in the Paleocene in particular, probably to take advantage of
28950-432: The middle Paleocene. The strata immediately overlaying the K–Pg extinction event are especially rich in fern fossils. Ferns are often the first species to colonize areas damaged by forest fires , so this " fern spike " may mark the recovery of the biosphere following the impact (which caused blazing fires worldwide). The diversifying herb flora of the early Paleocene either represent pioneer species which re-colonized
29143-705: 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
29336-402: 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
29529-546: The newly evolving birds and mammals for seed dispersal . In what is now the Gulf Coast , angiosperm diversity increased slowly in the early Paleocene, and more rapidly in the middle and late Paleocene. This may have been because the effects of the K–Pg extinction event were still to some extent felt in the early Paleocene, the early Paleocene may not have had as many open niches, early angiosperms may not have been able to evolve at such an accelerated rate as later angiosperms, low diversity equates to lower evolution rates, or there
29722-535: The non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene Thermal Maximum (PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification . In the Paleocene, the continents of the Northern Hemisphere were still connected via some land bridges ; and South America, Antarctica, and Australia had not completely separated yet. The Rocky Mountains were being uplifted,
29915-449: The north, Greenland in the east and Baffin Island in the west. It is an example of a failed proto-ocean, centrally underlain by oceanic crust of the Baffin Basin which is surrounded by extended continental crust that varies approximately 25 to 30 km (16 to 19 mi) thick. Connected to the North Atlantic Ocean in the south through Davis Strait and to the Arctic Ocean in the north through Nares Strait, Jones Sound and Lancaster Sound,
30108-400: The north-northeasterly trending Hudson, Snorri, Minna and Leif fracture zones. The change in trend corresponds with a more northerly spreading direction of the Mid-Labrador Ridge during the Eocene. Sverdrup Basin is a Carboniferous rift basin in the Queen Elizabeth Islands that formed during the Boreal Rifting Episode. It has a northeast–southwest axis of about 1,300 km (810 mi) and
30301-493: 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 ,
30494-440: 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
30687-413: The northwest coast of Baffin Island's Brodeur Peninsula . The main evidence of the Prince Regent Fault is the straightness of Somerset Island's east coast, but the southern end of this fault also connects with a lineament that is a known fault on land. A series of fracture zones are present in the Labrador Sea. These include the northeasterly trending Julian Haab and Cartwright fracture zones, as well as
30880-417: The northwestern part of Baffin Island from the south side of Lancaster Sound. At the west end of Parry Channel, Prince of Wales Strait leads southwest from the junction of Viscount Melville Sound and M'Clure Strait into Amundsen Gulf . Jones Sound occupies a rift valley between Ellesmere Island in the north and Devon Island in the south. It has an east–west length of roughly 210 km (130 mi) and
31073-419: The ocean water in Baffin Bay is highly stratified. The surface water, of Arctic origin, is cold and fresh. Below the Arctic layer is a layer of Atlantic origin, which is warm and saline. Below the Atlantic layer are Baffin Bay Deep Water and Baffin Bay Bottom Water, both of which are cold and saline. On a net annual basis, approximately 1.7 Sv of water flows out of the Arctic Ocean through Baffin Bay, making
31266-434: The original areas the stages were defined, accessibility, and the protected status of the area due to its geological significance. The Selandian was first proposed by Danish geologist Alfred Rosenkrantz in 1924 based on a section of fossil-rich glauconitic marls overlain by gray clay which unconformably overlies Danian chalk and limestone . The area is now subdivided into the Æbelø Formation , Holmehus Formation , and
31459-515: The poles—but they had low species richness in regards to plant life, and were populated by mainly small creatures that were rapidly evolving to take advantage of the recently emptied Earth. Though some animals attained great size, most remained rather small. The forests grew quite dense in the general absence of large herbivores. Mammals proliferated in the Paleocene, and the earliest placental and marsupial mammals are recorded from this time, but most Paleocene taxa have ambiguous affinities . In
31652-444: The proliferation of sulfate-reducing microorganisms which create highly toxic hydrogen sulfide H 2 S as a waste product. During the event, the volume of sulfidic water may have been 10–20% of total ocean volume, in comparison to today's 1%. This may have also caused chemocline upwellings along continents and the dispersal of H 2 S into the atmosphere. During the PETM there was a temporary dwarfing of mammals apparently caused by
31845-503: The proposal was officially published in 2006. The Selandian and Thanetian are both defined in Itzurun beach by the Basque town of Zumaia , 43°18′02″N 2°15′34″W / 43.3006°N 2.2594°W / 43.3006; -2.2594 , as the area is a continuous early Santonian to early Eocene sea cliff outcrop . The Paleocene section is an essentially complete, exposed record 165 m (541 ft) thick, mainly composed of alternating hemipelagic sediments deposited at
32038-403: The province suggests that mafic magmatism peaked during two time intervals. The first time interval between 127 and 129 million years ago was characterized by the widespread intrusion of sills and dikes. Flood basalt volcanism during the second time interval between 92 and 98 million years ago was coeval with the development of the proto-Arctic Ocean. Sills and flood basalts of
32231-421: 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
32424-404: The recently emptied landscape, or a response to the increased amount of shade provided in a forested landscape. Lycopods , ferns, and angiosperm shrubs may have been important components of the Paleocene understory . In general, the forests of the Paleocene were species-poor, and diversity did not fully recover until the end of the Paleocene. For example, the floral diversity of what is now
32617-494: The region at the PETM. During the Paleocene, the continents continued to drift toward their present positions. In the Northern Hemisphere, the former components of Laurasia (North America and Eurasia) were, at times, connected via land bridges: Beringia (at 65.5 and 58 mya) between North America and East Asia, the De Geer route (from 71 to 63 mya) between Greenland and Scandinavia , the Thulean route (at 57 and 55.8 mya) between North America and Western Europe via Greenland, and
32810-500: 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
33003-415: 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
33196-652: The same is true in the North Dakotan Almont/Beicegel Creek —such as Ochnaceae , Cyclocarya , and Ginkgo cranei —indicating the same floral families have characterized South American rainforests and the American Western Interior since the Paleocene. The extinction of large herbivorous dinosaurs may have allowed the forests to grow quite dense, and there is little evidence of wide open plains. Plants evolved several techniques to cope with high plant density, such as buttressing to better absorb nutrients and compete with other plants, increased height to reach sunlight, larger diaspore in seeds to provide added nutrition on
33389-519: The seas, ray-finned fish rose to dominate open ocean and recovering reef ecosystems. The word "Paleocene" was first used by French paleobotanist and geologist Wilhelm Philipp Schimper in 1874 while describing deposits near Paris (spelled "Paléocène" in his treatise). By this time, Italian geologist Giovanni Arduino had divided the history of life on Earth into the Primary ( Paleozoic ), Secondary ( Mesozoic ), and Tertiary in 1759; French geologist Jules Desnoyers had proposed splitting off
33582-425: The southeastern part of the basin are a series of seamounts that gradually decrease in height to the northwest. Geophysical data suggest they are the tops of the buried Mid-Labrador Ridge, which in the southeast is conjugated with the Mid-Atlantic Ridge. The P wave velocity structure under the Labrador Basin resembles that of the Mid-Atlantic Ridge, supporting the interpretation that the Canadian Arctic Rift System
33775-435: The southern West Greenland shelf in the northeast, the Labrador shelf in the southwest and the Baffin Island shelf in the northwest. An intermediate cold water mass known as Labrador Sea Water is formed by convective processes in the Labrador Sea. It represents a key component of the Atlantic Meridional Overturning Circulation , which is a major contributor to the transport and storage of heat, freshwater and other tracers in
33968-427: The strait: the Disko- Svartenhuk area of West Greenland in the east and near Cape Dyer on Baffin Island in the west. Hudson Strait – Evans Strait – Foxe Channel is a 1,000-kilometre-long (620 mi) waterbody connecting Hudson Bay and Foxe Basin in the west-northwest with the Labrador Sea in the south-southeast. It comprises several half-grabens that may have developed during the initial stages of extension in
34161-403: The upper limit, average sea surface temperatures (SSTs) at 60° N and S would have been the same as deep sea temperatures, at 30° N and S about 23 °C (73 °F), and at the equator about 28 °C (82 °F). In the Danish Palaeocene sea, SSTs were cooler than those of the preceding Late Cretaceous and the succeeding Eocene. The Paleocene foraminifera assemblage globally indicates
34354-498: The upward excursion in temperature. The warm, wet climate supported tropical and subtropical forests worldwide, mainly populated by conifers and broad-leafed trees. In Patagonia, the landscape supported tropical rainforests , cloud rainforests , mangrove forests , swamp forests , savannas , and sclerophyllous forests. In the Colombian Cerrejón Formation , fossil flora belong to the same families as modern day flora—such as palm trees , legumes , aroids , and malvales —and
34547-416: The world by a high- iridium band, as well as discontinuities with fossil flora and fauna. It is generally thought that a 10 to 15 km (6 to 9 mi) wide asteroid impact, forming the Chicxulub Crater in the Yucatán Peninsula in the Gulf of Mexico , and Deccan Trap volcanism caused a cataclysmic event at the boundary resulting in the extinction of 75% of all species. The Paleocene ended with
34740-442: 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,
34933-437: Was coeval with an early stage of the Boreal Rifting Episode. This was followed by a second time interval of tectonism from the latest Cretaceous to early Tertiary when the Boreal Rifting Episode was active and the Eurekan Rifting Episode was in an early stage of development. A third and final time interval of tectonism during the Miocene or Pliocene coincided with the final phase of the Eurekan Rifting Episode, during which time
35126-455: Was due to an ejection of 2,500–4,500 gigatons of carbon into the atmosphere, most commonly explained as the perturbation and release of methane clathrate deposits in the North Atlantic from tectonic activity and resultant increase in bottom water temperatures. Other proposed hypotheses include methane release from the heating of organic matter at the seafloor rather than methane clathrates, or melting permafrost . The duration of carbon output
35319-568: 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
35512-400: Was in Quebec City, Quebec in 1608 Paleocene The Paleocene ( IPA : / ˈ p æ l i . ə s iː n , - i . oʊ -, ˈ p eɪ l i -/ PAL -ee-ə-seen, -ee-oh-, PAY -lee- ), or Palaeocene , is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era . The name
35705-422: Was marked by continental extension in the mid-Tertiary. It breached the North American continent and reached the Arctic Ocean , resulting in the formation of the Parry and Nares submarine rift valleys , the Queen Elizabeth Islands and the Queen Elizabeth Islands Subplate . This rifting lasted until the Early Miocene or later. Little seismicity takes place on the Canadian Arctic Rift System, indicating that it
35898-530: Was not a major contributor to the greenhouse climate, and deep water temperatures more likely change as a response to global temperature change rather than affecting it. In the Arctic, coastal upwelling may have been largely temperature and wind-driven. In summer, the land surface temperature was probably higher than oceanic temperature, and the opposite was true in the winter, which is consistent with monsoon seasons in Asia. Open-ocean upwelling may have also been possible. The Paleocene climate was, much like in
36091-429: Was not much angiosperm migration into the region in the early Paleocene. Over the K–Pg extinction event, angiosperms had a higher extinction rate than gymnosperms (which include conifers, cycads , and relatives) and pteridophytes (ferns, horsetails , and relatives); zoophilous angiosperms (those that relied on animals for pollination) had a higher rate than anemophilous angiosperms; and evergreen angiosperms had
36284-440: Was officially defined as the Paleocene, Eocene, and Oligocene Epochs; and the Neogene as the Miocene and Pliocene Epochs. In 1989, Tertiary and Quaternary were removed from the time scale due to the arbitrary nature of their boundary, but Quaternary was reinstated in 2009. The term "Paleocene" is a portmanteau combination of the Ancient Greek palaios παλαιός meaning "old", and the word "Eocene", and so means "the old part of
36477-439: Was one of the most significant periods of global change during the Cenozoic. Geologists divide the rocks of the Paleocene into a stratigraphic set of smaller rock units called stages , each formed during corresponding time intervals called ages. Stages can be defined globally or regionally. For global stratigraphic correlation, the ICS ratify global stages based on a Global Boundary Stratotype Section and Point (GSSP) from
36670-417: Was shown that the Danian and the Montian are the same, the ICS decided to define the Danian as starting with the K–Pg boundary, thus ending the practice of including the Danian in the Cretaceous. In 1991, the GSSP was defined as a well-preserved section in the El Haria Formation near El Kef , Tunisia, 36°09′13″N 8°38′55″E / 36.1537°N 8.6486°E / 36.1537; 8.6486 , and
36863-425: Was still connected to South America and Australia, and, because of this, the Antarctic Circumpolar Current —which traps cold water around the continent and prevents warm equatorial water from entering—had not yet formed. Its formation may have been related in the freezing of the continent. Warm coastal upwellings at the poles would have inhibited permanent ice cover. Conversely, it is possible deep water circulation
37056-416: 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
37249-436: Was wetter than the Northern, or the Southern experienced less evaporation than the Northern. In either case, this would have made the Northern more saline than the Southern, creating a density difference and a downwelling in the North Pacific traveling southward. Deep water formation may have also occurred in the South Atlantic. It is largely unknown how global currents could have affected global temperature. The formation of
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