1.
Makhtesh Ramon
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Makhtesh Ramon is a geological feature of Israels Negev desert. The crater is 40 km long, 2–10 km wide and 500 meters deep, the only settlement in the area is the small town of Mitzpe Ramon located on the northern edge of the crater. Today the crater and surrounding area forms Israels largest national park, hundreds of millions of years ago, the Negev desert was covered by an ocean. Slowly, this started to recede northwards leaving behind a hump-shaped hill, the hump was slowly flattened by water and climatic forces. Approximately five million years ago, the Arava Rift Valley was formed, with changing their courses. The crater bottom continued to deepen at a faster rate than the surrounding walls. As the crater deepened, more layers of ancient rock were exposed with rocks at the bottom of the crater being up to 200 million years old, Makhtesh Ramon contains a diversity of rocks including clay hills known for their fantastic red and yellow colors and forms. Limestone covered by basalt can also be found in smaller hills in the southern part of the makhtesh. Shen Ramon is a made of magma which hardened whilst underground. It later rose up through cracks in the Earths surface, and today stands in striking contrast with the nearby creamy coloured southern wall of the crater, as a black sharp-edged rock. In the centre of the makhtesh is HaMinsara, a low hill made up of columnar jointed sandstone - polygonal prismatic columns of quartzite, the pterioid bivalve Family Ramonalinidae is found in early Middle Triassic rocks of Makhtesh Ramon and was named after this feature. The Asian wild ass has been reintroduced to Makhtesh Ramon, in 1995 the population had increased to 40 adults in the area. The animals are hybrids of two different subspecies of the Asian Wild Ass and it is derived from the Turkmenian kulan and the Persian onager. The original subspecies, the Syrian wild ass, is completely extinct, other larger mammals of the area include Nubian ibexes, Dorcas gazelles, striped hyenas and few Arabian leopards. The ruins of a prehistoric stone structure known as Khan Saharonim are found in the makhtesh, as it lies along the ancient Incense Route. These ruins acted as a way station for the traders and their animals as they proceeded further westwards to the Mediterranean seaport city of Gaza, mazor, Emanuel and Krasnov, Boris, editors The Makhteshim Country - a Laboratory of Nature. Birds eye view of Ramon Crater
2.
Shiprock
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Shiprock is a monadnock rising nearly 1,583 feet above the high-desert plain of the Navajo Nation in San Juan County, New Mexico, United States. Its peak elevation is 7,177 feet above sea level and it lies about 10.75 miles southwest of the town of Shiprock, which is named for the peak. Governed by the Navajo Nation, the formation is in the Four Corners region and plays a significant role in Navajo religion, myth, and tradition. It is located in the center of the occupied by the Ancient Pueblo People. Shiprock is a point of interest for rock climbers and photographers and has featured in several film productions. It is the most prominent landmark in northwestern New Mexico, the Navajo name for the peak, Tsé Bitʼaʼí, rock with wings or winged rock, refers to the legend of the great bird that brought the Navajo from the north to their present lands. The name Shiprock or Shiprock Peak or Ship Rock derives from the resemblance to an enormous 19th-century clipper ship. Americans first called the peak The Needle, a given to the topmost pinnacle by Captain J. F. McComb in 1860. United States Geological Survey maps indicate that the name Ship Rock dates from the 1870s, Shiprock is composed of fractured volcanic breccia and black dikes of igneous rock called minette. It is the remnant of the throat of a volcano. The rock probably was originally formed 2, 500–3,000 feet below the Earths surface, wall-like sheets of minette, known as dikes, radiate away from the central formation. Radiometric age determinations of the minette establish that these volcanic rocks solidified about 27 million years ago, Shiprock is in the northeastern part of the Navajo Volcanic Field—a field that includes intrusions and flows of minette and other unusual igneous rocks that formed about 25 million years ago. Agathla in Monument Valley is another prominent volcanic neck in this volcanic field, Shiprock and the surrounding land have religious and historical significance to the Navajo people. It is mentioned in many of their myths and legends, foremost is the peaks role as the agent that brought the Navajo to the southwest. According to one legend, after being transported from another place, one day, the peak was struck by lightning, obliterating the trail and leaving only a sheer cliff, and stranding the women and children on top to starve. The presence of people on the peak is forbidden for fear they might stir up the chį́įdii, Navajo legend puts the peak in a larger geographic context. Shiprock is said to be either a medicine pouch or a bow carried by the Goods of Value Mountain, the Chuska Mountains comprise the body, Chuska Peak is the head, the Carrizo Mountains are the legs, and Beautiful Mountain is the feet. Navajo legend has it that Bird Monsters nested on the peak, after Monster Slayer, elder of the Warrior Twins, destroyed Déélééd at Red Mesa, he killed two adult Bird Monsters at Shiprock and changed two young ones into an eagle and an owl
3.
Volcanic plug
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A volcanic plug, also called a volcanic neck or lava neck, is a volcanic object created when magma hardens within a vent on an active volcano. When present, a plug can cause an extreme build-up of pressure if rising volatile-charged magma is trapped beneath it, glacial erosion can lead to exposure of the plug on one side, while a long slope of material remains on the opposite side. Such landforms are called crag and tail, if a plug is preserved, erosion may remove the surrounding rock while the erosion-resistant plug remains, producing a distinctive upstanding landform. An example of two volcanic plugs can be found at the Pitons, in Saint Lucia, as they rise out of the eastern Caribbean Sea. Near the village of Rhumsiki in the Far North Province of Cameroon, spectacular volcanic plugs are present in the center of La Gomera island in the Canary Islands archipelago, within the Garajonay National Park. In New Zealands South Island, Ōnawe Peninsula on Banks Peninsula is a prominent volcanic plug, in Australia, the The Nut in Tasmania is a further example, along with Mount Warning. Borgarvirki is a volcanic plug located in north Iceland, a volcanic plug is situated in the town of Motta SantAnastasia in Italy. Saint Michel dAiguilhe chapel, whose construction started in 969, near Le Puy-en-Velay in France, the volcanic plug rises about 85 metres above the surroundings. Another building on a plug is the 14th century Trosky Castle in the Czech Republic. Rockall, a small, uninhabited, remote islet in the North Atlantic Ocean, is also a volcanic plug, in the United Kingdom, two examples of a building on a volcanic plug are the Castle Rock in Edinburgh, Scotland, and Deganwy Castle, Wales. The Law, Dundee, Ailsa Craig, Bass Rock, North Berwick Law, there are over 30 volcanic plugs in Northern Ireland, including Slemish in Ballymena, Tievebulliagh, Scawt Hill, Carrickarede, Scrabo and Slieve Gallion. Examples of volcanic plugs in the United States include Morro Rock, California and Laurel Hill, Devils Tower in Wyoming, as well as Little Devils Postpile located in Yosemite National Park, are also thought to be a volcanic plug by many geologists. Another example of a plug in the eastern USA is the highly eroded Starks Knob basaltic structure located along the Hudson River near Saratoga Springs. However, some geologists believe Starks Knob is not a plug at all, the origin of Devils Tower is not totally clear. Although it is admitted that it was formed by igneous intrusion, it is not necessarily a volcanic plug. In New Mexico, Shiprock is a further example, the Pitons of Saint Lucia, in the eastern Caribbean Sea are two volcanic plugs that rise abruptly out of the sea and are part of a UNESCO World Heritage site. The highest mountain plug rises to a height of nearly 760 metres, in Canada, the Castle Rock, located in British Columbia, is a volcanic plug that had volatile-charged magma still beneath it, leading to a Volcanic Explosivity Index 2 eruption
4.
New Mexico
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New Mexico is a state located in the southwestern region of the United States of America. It was admitted to the Union as the 47th state on January 6,1912 and it is usually considered one of the Mountain States. New Mexico is fifth by area, the 36th-most populous, inhabited by Native Americans for thousands of years before European exploration, New Mexico was colonized by the Spanish in 1598 Imperial Spanish viceroyalty of New Spain. Later, it was part of independent Mexico before becoming a U. S. territory and eventually a U. S. state as a result of the Mexican–American War. Among U. S. states, New Mexico has the highest percentage of Hispanics, the major Native American nations in the state are Navajo, Pueblo, and Apache peoples. The demography and culture of the state are shaped by these strong Hispanic and Native American influences and its scarlet and gold colors are taken from the royal standards of Spain, along with the ancient sun symbol of the Zia, a Pueblo-related tribe. New Mexico, or Nuevo México in Spanish, is incorrectly believed to have taken its name from the nation of Mexico. The name simply stuck, even though the area had no connection to Mexico or the Mexica Indian tribes, Mexico, formerly a part of New Spain, adopted its name centuries later in 1821, after winning independence from Spanish rule. New Mexico was a part of the independent Mexican Empire and Federal Republic of Mexico for 27 years,1821 through 1848, New Mexico and Mexico developed as neighboring Spanish-speaking communities under Spanish rule, with relatively independent histories. The states total area is 121,412 square miles, the eastern border of New Mexico lies along 103° W longitude with the state of Oklahoma, and 2.2 miles west of 103° W longitude with Texas. On the southern border, Texas makes up the eastern two-thirds, while the Mexican states of Chihuahua and Sonora make up the western third, the western border with Arizona runs along the 109°03 W longitude. The southwestern corner of the state is known as the Bootheel, the 37° N latitude parallel forms the northern boundary with Colorado. The states New Mexico, Colorado, Arizona, and Utah come together at the Four Corners in the corner of New Mexico. New Mexico, although a state, has very little water. Its surface water area is about 250 square miles, the New Mexican landscape ranges from wide, rose-colored deserts to broken mesas to high, snow-capped peaks. Despite New Mexicos arid image, heavily forested mountain wildernesses cover a significant portion of the state, the Sangre de Cristo Mountains, the southernmost part of the Rocky Mountains, run roughly north-south along the east side of the Rio Grande in the rugged, pastoral north. The most important of New Mexicos rivers are the Rio Grande, Pecos, Canadian, San Juan, the Rio Grande is tied for the fourth-longest river in the United States. Tourists visiting these sites bring significant money to the state, other areas of geographical and scenic interest include Kasha-Katuwe Tent Rocks National Monument and the Gila Wilderness in the southwest of the state
5.
Geology
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Geology is an earth science concerned with the solid Earth, the rocks of which it is composed, and the processes by which they change over time. Geology can also refer generally to the study of the features of any terrestrial planet. Geology gives insight into the history of the Earth by providing the evidence for plate tectonics, the evolutionary history of life. Geology also plays a role in engineering and is a major academic discipline. The majority of data comes from research on solid Earth materials. These typically fall into one of two categories, rock and unconsolidated material, the majority of research in geology is associated with the study of rock, as rock provides the primary record of the majority of the geologic history of the Earth. There are three types of rock, igneous, sedimentary, and metamorphic. The rock cycle is an important concept in geology which illustrates the relationships between three types of rock, and magma. When a rock crystallizes from melt, it is an igneous rock, the sedimentary rock can then be subsequently turned into a metamorphic rock due to heat and pressure and is then weathered, eroded, deposited, and lithified, ultimately becoming a sedimentary rock. Sedimentary rock may also be re-eroded and redeposited, and metamorphic rock may also undergo additional metamorphism, all three types of rocks may be re-melted, when this happens, a new magma is formed, from which an igneous rock may once again crystallize. Geologists also study unlithified material which typically comes from more recent deposits and these materials are superficial deposits which lie above the bedrock. Because of this, the study of material is often known as Quaternary geology. This includes the study of sediment and soils, including studies in geomorphology, sedimentology and this theory is supported by several types of observations, including seafloor spreading, and the global distribution of mountain terrain and seismicity. This coupling between rigid plates moving on the surface of the Earth and the mantle is called plate tectonics. The development of plate tectonics provided a basis for many observations of the solid Earth. Long linear regions of geologic features could be explained as plate boundaries, mid-ocean ridges, high regions on the seafloor where hydrothermal vents and volcanoes exist, were explained as divergent boundaries, where two plates move apart. Arcs of volcanoes and earthquakes were explained as convergent boundaries, where one plate subducts under another, transform boundaries, such as the San Andreas Fault system, resulted in widespread powerful earthquakes. Plate tectonics also provided a mechanism for Alfred Wegeners theory of continental drift and they also provided a driving force for crustal deformation, and a new setting for the observations of structural geology
6.
Sedimentary rock
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Sedimentary rocks are types of rock that are formed by the deposition and subsequent cementation of that material at the Earths surface and within bodies of water. Sedimentation is the name for processes that cause mineral and/or organic particles to settle in place. The particles that form a rock by accumulating are called sediment. Sedimentation may also occur as minerals precipitate from solution or shells of aquatic creatures settle out of suspension. The sedimentary rock cover of the continents of the Earths crust is extensive, sedimentary rocks are only a thin veneer over a crust consisting mainly of igneous and metamorphic rocks. Sedimentary rocks are deposited in layers as strata, forming a structure called bedding, sedimentary rocks are also important sources of natural resources like coal, fossil fuels, drinking water or ores. The study of the sequence of rock strata is the main source for an understanding of the Earths history, including palaeogeography, paleoclimatology. The scientific discipline that studies the properties and origin of rocks is called sedimentology. Sedimentology is part of both geology and physical geography and overlaps partly with other disciplines in the Earth sciences, such as pedology, geomorphology, geochemistry, sedimentary rocks have also been found on Mars. Clastic sedimentary rocks are composed of rock fragments that were cemented by silicate minerals. Clastic rocks are composed largely of quartz, feldspar, rock fragments, clay minerals, and mica, any type of mineral may be present, clastic sedimentary rocks, are subdivided according to the dominant particle size. Most geologists use the Udden-Wentworth grain size scale and divide unconsolidated sediment into three fractions, gravel, sand, and mud and this tripartite subdivision is mirrored by the broad categories of rudites, arenites, and lutites, respectively, in older literature. The subdivision of these three categories is based on differences in clast shape, conglomerates and breccias), composition. Conglomerates are dominantly composed of rounded gravel, while breccias are composed of dominantly angular gravel, composition of framework grains The relative abundance of sand-sized framework grains determines the first word in a sandstone name. Naming depends on the dominance of the three most abundant components quartz, feldspar, or the lithic fragments that originated from other rocks, all other minerals are considered accessories and not used in the naming of the rock, regardless of abundance. Clean sandstones with open space are called arenites. Muddy sandstones with abundant muddy matrix are called wackes, six sandstone names are possible using the descriptors for grain composition and the amount of matrix. Mudrocks are sedimentary rocks composed of at least 50% silt- and clay-sized particles and these relatively fine-grained particles are commonly transported by turbulent flow in water or air, and deposited as the flow calms and the particles settle out of suspension
7.
Clastic dike
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A clastic dike is a seam of sedimentary material that fills an open fracture in and cuts across sedimentary rock strata or layering in other rock types. Clastic dikes form rapidly by fluidized injection or passively by water, wind, diagenesis may play a role in the formation of some dikes. Clastic dikes are vertical or near-vertical. Centimeter-scale widths are common, but thicknesses range from millimetres to metres, length is usually many times width. Clastic dikes are found in sedimentary basin deposits worldwide, formal geologic reports of clastic dikes began to emerge in the early 19th century. Clastic dike environments include, Clastic dikes associated with earthquakes - An incredible variety of dikes is found in the geologic record, however, clastic dikes are typically produced by seismic disturbance and liquefaction of high water content sediments. Examples of this type are many, Clastic dikes are paleoseismic indicators in certain geologic settings. Several qualitative, field-based systems have developed to help distinguish seismites from soft sediment deformation features formed by non-seismic processes. Results from analytical modeling of clastic dike injection in soft rocks indicate propagation occurred at a rate of approximately 4 to 65 m/s at driving pressures of 1-2 MPa, emplacement duration is similar to the speed with which acoustic energy moves through partially lithified sedimentary rock. Clastic dikes associated with debris flows - Sandstone dikes formed by downward injection are found along Black Dragon wash upstream of the famous petroglyphs area, San Rafael Swell, Utah. Commonly, the fill is composed of grains, evidence that the injected material was lithified prior to impact and was crushed during injection into fractures. Clastic dikes associated with salt domes - Clastic dike swarms associated with salt dome diapirism are reported from the Dead Sea region, Clastic dikes associated with glaciers - Sand injection features are reported to have formed under heavy loads and confining pressures beneath grounding glacial ice. Clastic dikes in resistant bedrock - Though unusual, a significant number of reports describe sedimentary material intruding fractured crystalline bedrock, some of the articles referenced here describe lithified clastic dikes. Clastic dikes in storm deposits - Cyclic stresses from large waves can cause wet sediments to fluidize, tens of thousands of unusual clastic dikes penetrate sedimentary and bedrock units in the Columbia Basin of Washington, Oregon and Idaho. The dikes may be related to loading by outburst floods, other evidence suggests they are sediment-filled desiccation cracks. Some have suggested the dikes are ice wedge casts or features related to the melting of buried ice, earthquake shaking and liquefaction is invoked by others to explain the dikes. This action has taken place in open fissures, under water in fissures on the bed of the sea or other bodies of water, the filling from below has come about by pressure of some sort, in some cases undoubtedly hydrostatic
8.
Sediment
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For sediment in beverages, see dregs. For example, sand and silt can be carried in suspension in water and on reaching the sea be deposited by sedimentation. Sediments are most often transported by water, but also wind, beach sands and river channel deposits are examples of fluvial transport and deposition, though sediment also often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of transport and deposition. Glacial moraine deposits and till are ice-transported sediments, sediment can be classified based on its grain size and/or its composition. Sediment size is measured on a log base 2 scale, called the Phi scale, composition of sediment can be measured in terms of, parent rock lithology mineral composition chemical make-up. This leads to an ambiguity in which clay can be used as both a size-range and a composition, sediment is transported based on the strength of the flow that carries it and its own size, volume, density, and shape. Stronger flows will increase the lift and drag on the particle, causing it to rise, rivers and streams carry sediment in their flows. This sediment can be in a variety of locations within the flow and these relationships are shown in the following table for the Rouse number, which is a ratio of sediment fall velocity to upwards velocity. If the upwards velocity is less than the settling velocity, but still high enough for the sediment to move, it will move along the bed as bed load by rolling, sliding. If the upwards velocity is higher than the velocity, the sediment will be transported high in the flow as wash load. As there are generally a range of different particle sizes in the flow, sediment motion can create self-organized structures such as ripples, dunes, antidunes on the river or stream bed. These bedforms are often preserved in rocks and can be used to estimate the direction. Overland flow can erode soil particles and transport them downslope, the erosion associated with overland flow may occur through different methods depending on meteorological and flow conditions. If the initial impact of rain droplets dislodges soil, the phenomenon is called rainsplash erosion, if overland flow is directly responsible for sediment entrainment but does not form gullies, it is called sheet erosion. If the flow and the substrate permit channelization, gullies may form, glaciers carry a wide range of sediment sizes, and deposit it in moraines. The overall balance between sediment in transport and sediment being deposited on the bed is given by the Exner equation and this expression states that the rate of increase in bed elevation due to deposition is proportional to the amount of sediment that falls out of the flow. This can be localized, and simply due to obstacles, examples are scour holes behind boulders, where flow accelerates
9.
Alaska
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Alaska is a U. S. state located in the northwest extremity of North America. To the north are the Chukchi and Beaufort seas–the southern parts of the Arctic Ocean, the Pacific Ocean lies to the south and southwest. Alaska is the largest state in the United States by area, the 3rd least populous, approximately half of Alaskas residents live within the Anchorage metropolitan area. Alaskas economy is dominated by the fishing, natural gas, military bases and tourism are also a significant part of the economy. The United States purchased Alaska from the Russian Empire on March 30,1867, the area went through several administrative changes before becoming organized as a territory on May 11,1912. It was admitted as the 49th state of the U. S. on January 3,1959, the name Alaska was introduced in the Russian colonial period when it was used to refer to the peninsula. It was derived from an Aleut, or Unangam idiom, which refers to the mainland of Alaska. Literally, it means object to which the action of the sea is directed, Alaska is the northernmost and westernmost state in the United States and has the most easterly longitude in the United States because the Aleutian Islands extend into the Eastern Hemisphere. Alaska is the only non-contiguous U. S. state on continental North America and it is technically part of the continental U. S. but is sometimes not included in colloquial use, Alaska is not part of the contiguous U. S. often called the Lower 48. The capital city, Juneau, is situated on the mainland of the North American continent but is not connected by road to the rest of the North American highway system. Alaskas territorial waters touch Russias territorial waters in the Bering Strait, as the Russian Big Diomede Island, Alaska has a longer coastline than all the other U. S. states combined. Alaska is the largest state in the United States by total area at 663,268 square miles, over twice the size of Texas, Alaska is larger than all but 18 sovereign countries. Counting territorial waters, Alaska is larger than the area of the next three largest states, Texas, California, and Montana. It is also larger than the area of the 22 smallest U. S. states. Also referred to as the Panhandle or Inside Passage, this is the region of Alaska closest to the rest of the United States, as such, this was where most of the initial non-indigenous settlement occurred in the years following the Alaska Purchase. The region is dominated by the Alexander Archipelago as well as the Tongass National Forest and it contains the state capital Juneau, the former capital Sitka, and Ketchikan, at one time Alaskas largest city. The Alaska Marine Highway provides a vital transportation link throughout the area. The Interior is the largest region of Alaska, much of it is uninhabited wilderness, Fairbanks is the only large city in the region
10.
West Spanish Peak
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West Spanish Peak is a high and prominent mountain summit that is the higher of the two Spanish Peaks in the Rocky Mountains of North America. The summit of West Spanish Peak is the highest point in Las Animas County, the Spanish Peaks are two large igneous stocks which form an eastern outlier of the Culebra Range, a subrange of the Sangre de Cristo Mountains. West Spanish Peak is the easternmost 4000 meter mountain peak in the United States, due to its position well east of the Culebra Range and on the edge of the eastern plains of Colorado, West Spanish Peak enjoys great local vertical relief in almost all directions. For example, it rises over 6,000 ft in less than 6.5 miles on both its north and south flanks, though not a fourteener, West Spanish Peak is the twelfth most topographically prominent peak in the state. While the Spanish Peaks have the appearance of volcanic cones, they are actually stocks and they are surrounded by radiating dikes, up to 14 miles long, made of the same material. The standard ascent route for West Spanish Peak starts at Cordova Pass and it follows a trail for about 2 miles to treeline. From there, theres a path on talus up the southwest ridge of the peak for an additional 1.5 miles. The trail is very braided and has a tendency to go to the right, if climbers stay to the left and close to the ridge, the climbing is much easier. At about 13,000 is a large shale buttress to the right that usually has a pool of warm water at its foot. Once up on the part of the top ridge, its an easy hike to the actual summit. The top ridge tends to be 30–100 feet wide and is about 0.5 miles long before beginning a significant downward trend on the east side of the mountain, to the north and south are very steep descents. At the summit is a rock cairn with the usual PVC tube. This mountain is very unsafe when there is snow on the ground, best time to climb, early June through late October. Thunderstorm and lightning activity can be high in July, August, List of mountain peaks of North America List of mountain peaks of the United States List of mountain peaks of Colorado List of Colorado county high points West Spanish Peak on Summitpost
11.
Igneous rock
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Igneous rock, or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava, the magma can be derived from partial melts of existing rocks in either a planets mantle or crust. Typically, the melting is caused by one or more of three processes, an increase in temperature, a decrease in pressure, or a change in composition, solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, Igneous and metamorphic rocks make up 90–95% of the top 16 km of the Earths crust by volume. Igneous rocks form about 15% of the Earths current land surface, most of the Earths oceanic crust is made of igneous rock. In terms of modes of occurrence, igneous rocks can be either intrusive or extrusive, the mineral grains in such rocks can generally be identified with the naked eye. Intrusive rocks can also be classified according to the shape and size of the intrusive body, typical intrusive formations are batholiths, stocks, laccoliths, sills and dikes. When the magma solidifies within the earths crust, it cools slowly forming coarse textured rocks, such as granite, gabbro, the central cores of major mountain ranges consist of intrusive igneous rocks, usually granite. When exposed by erosion, these cores may occupy huge areas of the Earths surface, intrusive igneous rocks that form at depth within the crust are termed plutonic rocks and are usually coarse-grained. Intrusive igneous rocks that form near the surface are termed subvolcanic or hypabyssal rocks, hypabyssal rocks are less common than plutonic or volcanic rocks and often form dikes, sills, laccoliths, lopoliths, or phacoliths. Extrusive igneous rocks, also known as rocks, are formed at the crusts surface as a result of the partial melting of rocks within the mantle. Extrusive igneous rocks cool and solidify quicker than intrusive igneous rocks and they are formed by the cooling of molten magma on the earths surface. The magma, which is brought to the surface through fissures or volcanic eruptions, hence such rocks are smooth, crystalline and fine-grained. Basalt is an extrusive igneous rock and forms lava flows, lava sheets. Some kinds of basalt solidify to form long polygonal columns, the Giants Causeway in Antrim, Northern Ireland is an example. The molten rock, with or without suspended crystals and gas bubbles, is called magma and it rises because it is less dense than the rock from which it was created. When magma reaches the surface from beneath water or air, it is called lava, eruptions of volcanoes into air are termed subaerial, whereas those occurring underneath the ocean are termed submarine. Black smokers and mid-ocean ridge basalt are examples of volcanic activity
12.
Northwest Territories
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The Northwest Territories is a territory of Canada. At a land area of approximately 1,144,000 km2 and its estimated population as of 2016 is 44,291. Yellowknife became the capital in 1967, following recommendations by the Carrothers Commission. The Northwest Territories are bordered by Canadas two other territories, Nunavut to the east and Yukon to the west, and by the provinces of British Columbia, Alberta, and Saskatchewan to the south. The name is descriptive, adopted by the British government during the era to indicate where it lay in relation to Ruperts Land. It is shortened from North-Western Territory, in Inuktitut, the Northwest Territories are referred to as ᓄᓇᑦᓯᐊᖅ, beautiful land. There was some discussion of changing the name of the Northwest Territories after the splitting off of Nunavut, one proposal was Denendeh, as advocated by the former premier Stephen Kakfwi, among others. One of the most popular proposals for a new name – one to name the territory Bob – began as a prank, in the end a poll conducted prior to division showed that strong support remained to keep the name Northwest Territories. This name arguably became more appropriate following division than it had been when the territories extended far into Canadas north-central and it possibly meets Manitoba at a quadripoint to the extreme southeast, though surveys have not been completed. It has an area of 1,183,085 km2. Territorial islands in the Canadian Arctic Archipelago include Banks Island, Borden Island, Prince Patrick Island and its highest point is Mount Nirvana near the border with Yukon at an elevation of 2,773 m. The Northwest Territories extends for more than 1,300,000 km2 and has a large climate variant from south to north, the southern part of the territory has a subarctic climate, while the islands and northern coast have a polar climate. Summers in the north are short and cool, with highs in the mid teens Celsius. Winters are long and harsh, daytime highs in the mid −20 °C, extremes are common with summer highs in the south reaching 36 °C and lows reaching into the negatives. In winter in the south, it is not uncommon for the temperatures to reach −40 °C, in the north, temperatures can reach highs of 30 °C, and lows can reach into the low negatives. In winter in the north it is not uncommon for the temperatures to reach −50 °C, thunderstorms are not rare in the south. In the north they are rare, but do occur. Tornadoes are extremely rare but have happened with the most notable one happening just outside Yellowknife that destroyed a communications tower, the Territory has a fairly dry climate due to the mountains in the west
