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Mount Wokomung
Mount Wokomung is a sandstone tepui in the Pakaraima Mountains of western Guyana, the summit is 1700 metres. Together with Mount Ayanganna, 37 km to the north, Wokomung constitutes the easternmost tepui reaching above 1500 metres. The slopes of Mount Wokomung are covered with medium-high canopy montane forest The summit of Wokomung is a shallow bowl with poor drainage. It supports low woody shrubs and terrestrial bromeliads. Mount Wokomung supports some species which occur only on high tepuis in the Guiana Shield The Guiana Shield (french: Plateau des Guyanes, Bouclier guyanais; nl, Hoogland van Guyana, Guianaschild; pt, Planalto das Guianas, Escudo das Guianas; es, Escudo guayanés) is one of the three cratons of the South American Plate. It is a ... region References {{Reflist Mountains of Guyana Tepuis of Guyana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) because they are the most resistant minerals to weathering processes at the Earth's surface. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topographic features, certain colors of sandstone have been strongly identified with certain regions. Rock formations that are primarily composed of sandstone usually allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Quartz-bearing sandstone can be changed into quartzite through metamorphism, usually related to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tepui
A tepui , or tepuy (), is a table-top mountain or mesa found in South America, especially in Venezuela and western Guyana. The word tepui means "house of the gods" in the native tongue of the Pemon, the indigenous people who inhabit the Gran Sabana. Tepuis tend to be found as isolated entities rather than in connected ranges, which makes them the host of a unique array of endemic plant and animal species. Some of the most outstanding tepuis are Auyantepui, Autana, Neblina, and Mount Roraima. They are typically composed of sheer blocks of Precambrian quartz arenite sandstone that rise abruptly from the jungle, giving rise to spectacular natural scenery. Auyantepui is the source of Angel Falls, the world's tallest waterfall. Morphology These table-top mountains are the remains of a large sandstone plateau that once covered the granite basement complex between the north border of the Amazon Basin and the Orinoco, between the Atlantic coast and the Rio Negro. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pakaraima Mountains
The Pacaraima or Pakaraima Mountains ( pt, Serra de Pacaraima, es, Sierra de Pacaraima) are a mountain range primarily in southwestern Guyana, and into northern Brazil and eastern Venezuela. Geography The range extends from west to east for over . Its highest peak is Mount Roraima at above sea level, a tepui surrounded by cliffs high. It is geologically part of the Guayana Shield and biogeographically part of the Guayana Highlands.The mountains form the divide between the Orinoco Valley to the north and the Amazon Basin to the south. They also serve as a natural boundary in the east–west direction, where they extend to form a border marker between Brazil and southeastern Venezuela and between Brazil and west central Guyana. Geology The Pacaraimas are a sandstone plateau underlain by a horizonal precambrian marine strata that arose in post-cretaceous time. Erosion of the sandstone (the Roraima Supergroup) results in dramatic escarpments, the individual remnants of which ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guyana
Guyana ( or ), officially the Cooperative Republic of Guyana, is a country on the northern mainland of South America. Guyana is an indigenous word which means "Land of Many Waters". The capital city is Georgetown. Guyana is bordered by the Atlantic Ocean to the north, Brazil to the south and southwest, Venezuela to the west, and Suriname to the east. With , Guyana is the third-smallest sovereign state by area in mainland South America after Uruguay and Suriname, and is the second-least populous sovereign state in South America after Suriname; it is also one of the least densely populated countries on Earth. It has a wide variety of natural habitats and very high biodiversity. The region known as "the Guianas" consists of the large shield landmass north of the Amazon River and east of the Orinoco River known as the "land of many waters". Nine indigenous tribes reside in Guyana: the Wai Wai, Macushi, Patamona, Lokono, Kalina, Wapishana, Pemon, Akawaio and Warao. Histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Ayanganna
Mount Ayanganna is a sandstone tepui in the Pakaraima Mountains of western Guyana, and located east of Mount Roraima. With a height of it is the easternmost tepui taller than . It is part of the Guiana Shield and Guyana Highlands. Ecology The slopes of Mount Ayanganna are covered in tall-canopy lower montane forest, up to about 1100 metres. Above this elevation, there is a series of "steps" - relatively flat plateaus separated by steeper slopes. The poorly drained plateaus support low-canopy forest or terrestrial bromeliads. The slopes support medium-canopy high-montane forest. The amphibians and reptiles of Ayanganna have been surveyed. Mount Ayanganna is fully within Guyanese territory and is surrounded by rainforest. Culture In 1966, the national flag was planted on Mount Ayanganna to commemorate Independence. It is undertaken yearly by members of the Guyana Defence Force The Guyana Defence Force (GDF) is the military of Guyana, established in 1965. It has military ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacaraima Mountains
The Pacaraima or Pakaraima Mountains ( pt, Serra de Pacaraima, es, Sierra de Pacaraima) are a mountain range primarily in southwestern Guyana, and into northern Brazil and eastern Venezuela. Geography The range extends from west to east for over . Its highest peak is Mount Roraima at above sea level, a tepui surrounded by cliffs high. It is geologically part of the Guayana Shield and biogeographically part of the Guayana Highlands.The mountains form the divide between the Orinoco Valley to the north and the Amazon Basin to the south. They also serve as a natural boundary in the east–west direction, where they extend to form a border marker between Brazil and southeastern Venezuela and between Brazil and west central Guyana. Geology The Pacaraimas are a sandstone plateau underlain by a horizonal precambrian marine strata that arose in post-cretaceous time. Erosion of the sandstone (the Roraima Supergroup) results in dramatic escarpments, the individual remnants of which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montane Forest
Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial factor in shaping plant community, biodiversity, metabolic processes and ecosystem dynamics for montane ecosystems. Dense montane forests are common at moderate elevations, due to moderate temperatures and high rainfall. At higher elevations, the climate is harsher, with lower temperatures and higher winds, preventing the growth of trees and causing the plant community to transition to montane grasslands, shrublands or alpine tundra. Due to the unique climate conditions of montane ecosystems, they contain increased numbers of endemic species. Montane ecosystems also exhibit variation in ecosystem services, which include carbon storage and water supply. Life zones As elevation increases, the climate becomes cooler, due to a decrease in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromeliad
The Bromeliaceae (the bromeliads) are a family of monocot flowering plants of about 80 genera and 3700 known species, native mainly to the tropical Americas, with several species found in the American subtropics and one in tropical west Africa, ''Pitcairnia feliciana''. It is among the basal families within the Poales and is the only family within the order that has septal nectaries and inferior ovaries.Judd, Walter S. Plant systematics a phylogenetic approach. 3rd ed. Sunderland, MA: Sinauer Associates, Inc., 2007. These inferior ovaries characterize the Bromelioideae, a subfamily of the Bromeliaceae. The family includes both epiphytes, such as Spanish moss (''Tillandsia usneoides''), and terrestrial species, such as the pineapple (''Ananas comosus''). Many bromeliads are able to store water in a structure formed by their tightly overlapping leaf bases. However, the family is diverse enough to include the tank bromeliads, grey-leaved epiphyte ''Tillandsia'' species that gath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guiana Shield
The Guiana Shield (french: Plateau des Guyanes, Bouclier guyanais; nl, Hoogland van Guyana, Guianaschild; pt, Planalto das Guianas, Escudo das Guianas; es, Escudo guayanés) is one of the three cratons of the South American Plate. It is a 1.7 billion-year-old Precambrian geological formation in northeast South America that forms a portion of the northern coast. The higher elevations on the shield are called the Guiana Highlands, which is where the table-like mountains called tepuis are found. The Guiana Highlands are also the source of some of the world's most well-known waterfalls such as Angel Falls, Kaieteur Falls and Cuquenan Falls. The Guiana Shield underlies Guyana (previously British Guiana), Suriname (previously Dutch Guiana) and French Guiana (or Guyane), much of southern Venezuela, as well as parts of Colombia and Brazil. The rocks of the Guiana Shield consist of metasediments and metavolcanics ( greenstones) overlain by sub-horizontal layers of sandstones, quartz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountains Of Guyana
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher than a hill, typically rising at least 300 metres (1,000 feet) above the surrounding land. A few mountains are isolated summits, but most occur in mountain ranges. Mountains are formed through tectonic forces, erosion, or volcanism, which act on time scales of up to tens of millions of years. Once mountain building ceases, mountains are slowly leveled through the action of weathering, through slumping and other forms of mass wasting, as well as through erosion by rivers and glaciers. High elevations on mountains produce colder climates than at sea level at similar latitude. These colder climates strongly affect the ecosystems of mountains: different elevations have different plants and animals. Because of the less hospitable terrain and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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