Misplaced Pages

Avra Valley

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.

The Avra Valley is a 50-mile (80 km) long northwest–southeast valley, bordering the west of Tucson, Arizona . The Tucson Mountains are at the valley's center-east, with suburbs ranging east of the Tucson Mountains and trending northwest to the Avra Valley's northeast. This entire northwest stretch from Tucson contains the northwest trending Interstate 10 , the route to Casa Grande and Phoenix . The northeast of the valley contains Marana on I-10, the Pinal Airpark , an aircraft storage park, and other communities along I-10. Avra Valley Airport is a general aviation airport in Marana, located about 15 miles (24 km) northwest of Tucson, and being used for storage of classic propeller-era airliners.

#352647

38-496: The center-(west) of the valley is at Cocoraque Butte, 32°13′16″N 111°20′31″W  /  32.22119°N 111.34205°W  / 32.22119; -111.34205  ( Baldy Peak (Sierrieta Mountains) ) , extended northeast from the Roskruge Mountains . Cocoraque Butte's height is 2,758 feet (841 m). Avra Valley is a narrow valley, only about 10 miles wide in some locations, and bordered completely on

76-502: A more efficient path to the ocean than the existing Volga–Don Canal . This usage can also be seen in the names of Eurasianet , The Journal of Eurasian Studies , and the Association for Slavic, East European, and Eurasian Studies , as well as the titles of numerous academic programmes at US universities. This usage is comparable to how Americans use " Western Hemisphere " to describe concepts and organizations dealing with

114-604: Is a group of mountain ranges with similarity in form, structure, and alignment that have arisen from the same cause, usually an orogeny . Mountain ranges are formed by a variety of geological processes, but most of the significant ones on Earth are the result of plate tectonics . Mountain ranges are also found on many planetary mass objects in the Solar System and are likely a feature of most terrestrial planets . Mountain ranges are usually segmented by highlands or mountain passes and valleys . Individual mountains within

152-665: Is also in the southwest, at the junction of the valley going southwest to Sasabe , the Altar Valley . Robles Junction is also at the northwest of the mountain range on Avra Valley's southern border, the Sierrita Mountains . The north of the Avra Valley narrows at the Silver Bell Mountains and Marana to the east. The region merges into the wider flatlands associated with the floodplain regions of

190-538: Is at work while the mountains are being uplifted until the mountains are reduced to low hills and plains. The early Cenozoic uplift of the Rocky Mountains of Colorado provides an example. As the uplift was occurring some 10,000 feet (3,000 m) of mostly Mesozoic sedimentary strata were removed by erosion over the core of the mountain range and spread as sand and clays across the Great Plains to

228-753: Is connected to Africa at the Suez Canal , and the two are sometimes combined to describe the largest contiguous landmass on Earth, Afro-Eurasia . Primarily in the Northern and Eastern Hemispheres , Eurasia spans from Iceland and the Iberian Peninsula in the west to the Russian Far East , and from the Russian Far North to Maritime Southeast Asia in the south, but other specific geographical limits of Eurasia states that

266-780: Is considered a supercontinent , part of the supercontinent of Afro-Eurasia or simply a continent in its own right. In plate tectonics , the Eurasian Plate includes Europe and most of Asia but not the Indian subcontinent, the Arabian Peninsula or the area of the Russian Far East east of the Chersky Range . From the point of view of history and culture, Eurasia can be loosely subdivided into Western Eurasia and Eastern Eurasia . In geology, Eurasia

304-471: Is disputed, since Mount Elbrus would be part of Europe in the latter case, making it (and not Mont Blanc ) Europe's highest mountain. Most accepted is probably the boundary as defined by Philip Johan von Strahlenberg in the 18th century. He defined the dividing line along the Aegean Sea , Dardanelles , Sea of Marmara , Bosporus , Black Sea , Kuma–Manych Depression , Caspian Sea , Ural River , and

342-497: Is often considered as a single rigid megablock, but this is debated. Eurasia formed between 375 and 325 million years ago with the merging of Siberia , Kazakhstania , and Baltica , which was joined to Laurentia (now North America), to form Euramerica . This is a list of the longest rivers in Eurasia. Included are all rivers over 3,000 km (1,900 mi). All of the 100 highest mountains on Earth are in Eurasia, in

380-527: Is often used in Kazakhstan to describe its location. Numerous Kazakh institutions have the term in their names, like the L. N. Gumilev Eurasian National University ( Kazakh : Л. Н. Гумилёв атындағы Еуразия Ұлттық университеті ; Евразийский Национальный университет имени Л. Н. Гумилёва ) ( Lev Gumilev 's Eurasianism ideas having been popularized in Kazakhstan by Olzhas Suleimenov ),

418-487: Is recognized as the largest of the six, five, or four continents on Earth. Eurasia covers around 55 million square kilometres (21 million square miles), or around 36.2% of the Earth's total land area. The landmass contains well over 5 billion people, equating to approximately 70% of the human population . Humans first settled in Eurasia from Africa 125,000 years ago. Eurasia contains many peninsulas, including

SECTION 10

#1732798716353

456-440: Is the largest continental area on Earth, comprising all of Europe and Asia . According to some geographers, physiographically , Eurasia is a single supercontinent . The concepts of Europe and Asia as distinct continents date back to antiquity , but their borders have historically been subject to change. For example, to the ancient Greeks , Asia originally included Africa but they classified Europe as separate land. Eurasia

494-865: The Alpide belt . The Pacific Ring of Fire includes the Andes of South America, extends through the North American Cordillera , the Aleutian Range , on through Kamchatka Peninsula , Japan , Taiwan , the Philippines , Papua New Guinea , to New Zealand . The Andes is 7,000 kilometres (4,350 mi) long and is often considered the world's longest mountain system. The Alpide belt stretches 15,000 km across southern Eurasia , from Java in Maritime Southeast Asia to

532-1060: The Alps , the Arctic, the Pacific, the Atlantic, the Mediterranean, the Black Sea and the Caspian Sea, a definition that has been influential in Russia and other parts of the former Soviet Union. Nowadays, partly inspired by this usage, the term Eurasia is sometimes used to refer to the post-Soviet space – in particular Russia, the Central Asian republics, and the Transcaucasus republics – and sometimes also adjacent regions such as Turkey and Mongolia . The word "Eurasia"

570-551: The Annamite Range . If the definition of a mountain range is stretched to include underwater mountains, then the Ocean Ridge forms the longest continuous mountain system on Earth, with a length of 65,000 kilometres (40,400 mi). The position of mountain ranges influences climate, such as rain or snow. When air masses move up and over mountains, the air cools, producing orographic precipitation (rain or snow). As

608-635: The Arabian Peninsula , Korean Peninsula , Indian subcontinent , Anatolia Peninsula , Kamchatka Peninsula , and Europe, which itself contains peninsulas such as the Italian or Iberian Peninsula. Due to its vast size and differences in latitude , Eurasia exhibits all types of climates under the Köppen classification , including the harshest types of hot and cold temperatures, high and low precipitation, and various types of ecosystems . Eurasia

646-716: The Greeks classified Europe (derived from the mythological Phoenician princess Europa ) and Asia which to the Greeks originally included Africa (derived from Asia , a woman in Greek mythology ) as separate "lands". Where to draw the dividing line between the two regions is still a matter of discussion . Especially whether the Kuma-Manych Depression or the Caucasus Mountains form the southeast boundary

684-720: The Himalaya , Karakoram , Hindu Kush , Pamir , Hengduan , and Tian Shan mountain ranges, and all peaks above 7,000 metres are in these ranges and the Transhimalaya . Other high ranges include the Kunlun , Hindu Raj , and Caucasus Mountains . The Alpide belt stretches 15,000 km across southern Eurasia, from Java in Maritime Southeast Asia to the Iberian Peninsula in Western Europe , including

722-624: The Iberian Peninsula in Western Europe , including the ranges of the Himalayas , Karakoram , Hindu Kush , Alborz , Caucasus , and the Alps . The Himalayas contain the highest mountains in the world, including Mount Everest , which is 8,848 metres (29,029 ft) high. Mountain ranges outside these two systems include the Arctic Cordillera , Appalachians , Great Dividing Range , East Siberians , Altais , Scandinavians , Qinling , Western Ghats , Vindhyas , Byrrangas , and

760-655: The Mithrim Montes and Doom Mons on Titan, and Tenzing Montes and Hillary Montes on Pluto. Some terrestrial planets other than Earth also exhibit rocky mountain ranges, such as Maxwell Montes on Venus taller than any on Earth and Tartarus Montes on Mars . Jupiter's moon Io has mountain ranges formed from tectonic processes including the Boösaule , Dorian, Hi'iaka and Euboea Montes . Eurasia Eurasia ( / j ʊəˈr eɪ ʒ ə / yoor- AY -zhə , also UK : /- ʃ ə / -⁠shə )

798-549: The Soviet Union ) then dominated much of the continent until the end of the Cold War in 1991. Originally, "Eurasia" is a geographical notion: in this sense, it is simply the biggest continent; the combined landmass of Europe and Asia. However, geopolitically, the word has several meanings, reflecting specific geopolitical interests. "Eurasia" is one of the most important geopolitical concepts and it figures prominently in

SECTION 20

#1732798716353

836-641: The Ural Mountains . However, at least part of this definition has been subject to criticism by many modern analytical geographers like Halford Mackinder , who saw little validity in the Ural Mountains as a boundary between continents. Nineteenth-century Russian philosopher Nikolai Danilevsky defined Eurasia as an entity separate from Europe and Asia, bounded by the Himalayas, the Caucasus,

874-592: The heterogeneous dispositif such metapolitical constructs used to control and exercise power. Across Eurasia, several single markets have emerged, including the Eurasian Economic Space , European Single Market , ASEAN Economic Community , and the Gulf Cooperation Council . There are also several international organizations and initiatives which seek to promote integration throughout Eurasia, including: In ancient times,

912-837: The Eurasian Media Forum, the Eurasian Cultural Foundation ( Евразийский фонд культуры ), the Eurasian Development Bank ( Евразийский банк развития ), and the Eurasian Bank. In 2007 Kazakhstan's president, Nursultan Nazarbayev , proposed building a " Eurasia Canal " to connect the Caspian Sea and the Black Sea via Russia's Kuma-Manych Depression to provide Kazakhstan and other Caspian-basin countries with

950-481: The Western Hemisphere and Oceania geopolitically peripheral to the world's central continent. About 75 per cent of the world's people live in 'Eurasia', and most of the world's physical wealth is there as well, both in its enterprises and underneath its soil. 'Eurasia' accounts for about three-fourths of the world's known energy resources." The Russian " Eurasianism " corresponded initially more or less to

988-627: The air descends on the leeward side, it warms again (following the adiabatic lapse rate ) and is drier, having been stripped of much of its moisture. Often, a rain shadow will affect the leeward side of a range. As a consequence, large mountain ranges, such as the Andes, compartmentalize continents into distinct climate regions . Mountain ranges are constantly subjected to erosional forces which work to tear them down. The basins adjacent to an eroding mountain range are then filled with sediments that are buried and turned into sedimentary rock . Erosion

1026-407: The commentaries on the ideas of Halford Mackinder . As Zbigniew Brzezinski observed on Eurasia: "... how America 'manages' Eurasia is critical. A power that dominates 'Eurasia' would control two of the world's three most advanced and economically productive regions. A mere glance at the map also suggests that control over 'Eurasia' would almost automatically entail Africa's subordination, rendering

1064-485: The east. This mass of rock was removed as the range was actively undergoing uplift. The removal of such a mass from the core of the range most likely caused further uplift as the region adjusted isostatically in response to the removed weight. Rivers are traditionally believed to be the principal cause of mountain range erosion, by cutting into bedrock and transporting sediment. Computer simulation has shown that as mountain belts change from tectonically active to inactive,

1102-454: The land area of Imperial Russia in 1914, including parts of Eastern Europe . One of Russia's main geopolitical interests lies in ever closer integration with those countries that it considers part of "Eurasia." The term Eurasia gained geopolitical reputation as one of the three superstates in 1984 , George Orwell 's novel where constant surveillance and propaganda are strategic elements (introduced as reflexive antagonists ) of

1140-658: The least-densely populated. Eurasia has been the host of many ancient civilizations, including those based in Mesopotamia , the Indus Valley and China. In the Axial Age (mid- first millennium BCE ), a continuous belt of civilizations stretched through the Eurasian subtropical zone from the Atlantic to the Pacific. This belt became the mainstream of world history for two millennia. New connections emerged between

1178-514: The northwestern Santa Cruz River where it begins to merge with the Gila River . Saguaro National Park protects the northern Tucson Mountains in its West Unit bordering Avra Valley. Saguaro National Park features "forests" of Saguaro , Carnegiea gigantea . Mountain range A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt

Avra Valley - Misplaced Pages Continue

1216-597: The ranges of the Himalayas, Karakoram, Hindu Kush, Alborz , Caucasus, and the Alps . Long ranges outside the Alpide Belt include the East Siberian , Altai , Scandinavian , Qinling , Western Ghats , Vindhya , Byrranga , and Annamite Ranges . The largest Eurasian islands by area are Borneo , Sumatra , Honshu , Great Britain, Sulawesi , Java, Luzon , Iceland, Mindanao , Ireland , Hokkaido , Sakhalin , and Sri Lanka . The five most-populated islands in

1254-627: The rate of erosion drops because there are fewer abrasive particles in the water and fewer landslides. Mountains on other planets and natural satellites of the Solar System, including the Moon , are often isolated and formed mainly by processes such as impacts, though there are examples of mountain ranges (or "Montes") somewhat similar to those on Earth. Saturn 's moon Titan and Pluto , in particular, exhibit large mountain ranges in chains composed mainly of ices rather than rock. Examples include

1292-479: The same mountain range do not necessarily have the same geologic structure or petrology . They may be a mix of different orogenic expressions and terranes , for example thrust sheets , uplifted blocks , fold mountains, and volcanic landforms resulting in a variety of rock types . Most geologically young mountain ranges on the Earth's land surface are associated with either the Pacific Ring of Fire or

1330-710: The southern limit is in the Weber's line . Eurasia is bordered by Africa to the southwest, the Atlantic Ocean to the west, the Arctic Ocean to the north, the Pacific Ocean to the east, and the Indo-Mediterranean to the south. The division between Europe and Asia as two continents is a historical social construct , as neither fits the usual definition; thus, in some parts of the world, Eurasia

1368-516: The subregions of Eurasia from the Age of Discovery onwards, with the Iberians discovering new maritime routes in the 1490s, and the 1869 completion of the Suez Canal having paved the way for direct passage through the Indo-Mediterranean and the wave of Western European "New Imperialism" that dominated Africa and Asia until the mid-20th century. The communist presence in Eurasia (primarily driven by

1406-677: The west by low-elevation, arid mountain ranges . From the northwest, the mountains are the Silver Bell Mountains , Watermans , and then in the southwest the Roskruge Mountains . Much of these ranges to the West of Avra Valley are protected in Ironwood Forest National Monument . South of Roskruge, Arizona Route 86 enters the valley from the Tohono O'odham Nation to the west. Robles Junction, Arizona ,

1444-587: The world are Java, Honshu, Great Britain, Luzon, and Sumatra. Other Eurasian islands with large populations include Mindanao, Taiwan , Salsette , Borneo, Sri Lanka, Sulawesi, Kyushu , and Hainan . The most densely-populated islands in Eurasia are Caubian Gamay Island , Ap Lei Chau , and Navotas Island . In the Arctic Ocean, Severny Island , Nordaustlandet , October Revolution Island , and Bolshevik Island are Eurasia's largest uninhabited islands, and Kotelny Island , Alexandra Land , and Spitsbergen are

#352647