Inland dunes are eolian sand dunes that are found inland, away from coastal regions.
Inland dunes are eolian sand dunes that are found inland, away from coastal regions.
In Central Europe, towards the end of the last glacial period (about 12,000 years ago), it was about 10 degrees colder than today. There was therefore no forest cover but only patchy vegetation in the form of tundra. In addition, in the areas covered by the ice sheet, the vegetation had to re-establish itself as the glaciers melted. As a result, the winds could blow almost unhindered. Light, fine-grained soil particles, especially of silt and sand were plucked up by air currents, often transported for miles and then deposited at another location. The wind also had a sorting effect - silt is transported significantly faster than sand - and this resulted, over time, in areas of aeolian sand and sand dunes being formed, while the silt was transported much further and redeposited, for example, on the northern edge of highlands.
In high winds the dunes had a tendency to "wander". Most of the currently existing inland dunes were created at this time. With the end of the glacial period, the mobility of the dunes quickly came to a halt as a result of reforestation.
The shape of inland dunes varies depending on the prevailing wind direction and strength. Most of them are rather irregular dunes or shifting belts of sand. But there are also occur very well-formed parabolic dunes and longitudinal dunes.
Nearly all recent phases of the development of inland dunes are affected by human intervention on the vegetation cover. By the deliberate or unintentional clearing of the forest, dunes became mobile again in areas where they had become static.
The analysis of charcoal particles in the dunes using radiocarbon dating has established that the activity of settlers in the Neolithic period caused the dunes to become mobile again. But even in the Bronze and Iron Age there is evidence of man-induced dune activity.
Many inland eolian dunes are present in North America, including vegetated (stabilized) eolian dunes of the U.S. Atlantic Coastal Plain, dunes of Laurentian Great Lakes region, dunes of the Central and Southern Great Plains, the Nebraska Sand Hills, White Sands (New Mexico), Great Sand Dunes (Colorado), dunes of the southern Colorado Plateau, and dune fields of the Southwest Deserts. [1]
The sands of the inland dunes of El Vizcaíno Desert, Baja California, Mexico, come from nearby alluvial sources. Originally the sands are thought to have derived from granitoids, schists as well as sedimentary and volcanic rocks. While composition suggest that dune sands come from a craton setting geochemistry indicates an active continental margin setting for the origin of the sand. [2]
Large fossil dune fields or paleo-dune field exist in La Pampa Province of Argentina. These dune are vestiges of past climatic conditions that allowed for movement of sand. The dunes are not active any longer as result of the stabilizing effect of grasses. [3] However the dunes have been degraded by cattle grassing and agriculture. [3] A particular dune field covers the floor of a 40 km-long and 5 km broad NE-SW valley. It is made up of very large parabolic dunes with lesser blowout dunes built on top. [3]
Near Copiapó in the southern reaches of the Atacama Desert the largest dunes of Chile exists. Based on an analysis of sediments it has been suggested that the dunes derive from fluvial sediments. A previous explanation suggests that the dunes originated from coastal sand in marine terraces that were uplifted, then deflation would have caused this sand to migrate inland. At present the dunes are active but starved of sediment supply. [4]
Inland dunes in the Gran Chaco of Bolivia and Paraguay are concentrated at the Andean foothills. Most of these dunes are inactive with some being as old as 33–36 thousand years old. [5]
Within Central Europe, therefore, inland dunes exclude the belts of coastal dunes on the North Sea and Baltic Sea coasts. Unlike their coastal cousins, inland dunes are aeolian formations of sand (dunes) transported and then deposited by wind. They were predominantly created under cold climatic, periglacial conditions at the end of the Weichselian and Würm ice ages, i.e. roughly more than 10,000 years ago. Their development during the post-glacial period has been heavily influenced by mankind.
Best example of such continental sandfields is Deliblato Sands which is sometimes called the “Sahara of Europe”. It is mainly afforested today, and open sand surface is rare, although the sand is still moving (gradual aeolian blasting).
In northern Sweden numerous inactive dunes exists. These dunes were formed in a Holocene periglacial context when the Weichsel Ice Sheet was retreating. At present smaller parabolic dunes are forming in northern Sweden due to redeposition of deflated dunes. As recorded by dune stratification the wind the formed the larger and older dunes blew from northwestern directions. [6]
Inland dunes can also be found in Finnish Lapland north of the Arctic Circle and in Norway's Finnmark. [7]
A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, flat regions covered with wind-swept sand or dunes with little or no vegetation are called ergs or sand seas. Dunes occur in different shapes and sizes, but most kinds of dunes are longer on the stoss (upflow) side, where the sand is pushed up the dune, and have a shorter slip face in the lee side. The valley or trough between dunes is called a dune slack.
Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil or as sediment mixed in suspension with water. Silt usually has a floury feel when dry, and lacks plasticity when wet. Silt also can be felt by the tongue as granular when placed on the front teeth.
Carolina bays are elliptical to circular depressions concentrated along the East Coast of the United States within coastal New York, New Jersey, Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia, and north Florida. In Maryland, they are called Maryland basins. Within the Delmarva Peninsula, they and other coastal ponds are also called Delmarva bays.
Lake Waccamaw State Park is a North Carolina state park in Columbus County, North Carolina, in the United States. Located near the town of Lake Waccamaw, North Carolina, it covers 2,398-acre (9.70 km2), along the shores of Lake Waccamaw, a Carolina bay. Recent work by the U.S. Geological Survey has interpreted the Carolina Bays as relict thermokarst lakes that formed several thousands of years ago when the climate was colder, drier, and windier. Thermokarst lakes develop by thawing of frozen ground (permafrost) and by subsequent modification by wind and water. Thus, this interpretation suggests that permafrost once extended as far south as the Carolina Bays during the last ice age and (or) previous ice ages.
Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth. Winds may erode, transport, and deposit materials and are effective agents in regions with sparse vegetation, a lack of soil moisture and a large supply of unconsolidated sediments. Although water is a much more powerful eroding force than wind, aeolian processes are important in arid environments such as deserts.
A ridge is a long, narrow, elevated geomorphologic landform, structural feature, or a combination of both separated from the surrounding terrain by steep sides. The sides of a ridge slope away from a narrow top, the crest or ridgecrest, with the terrain dropping down on either side. The crest, if narrow, is also called a ridgeline. Limitations on the dimensions of a ridge are lacking. Its height above the surrounding terrain can vary from less than a meter to hundreds of meters. A ridge can be either depositional, erosional, tectonic, or a combination of these in origin and can consist of either bedrock, loose sediment, lava, or ice depending on its origin. A ridge can occur as either an isolated, independent feature or part of a larger geomorphological and/or structural feature. Frequently, a ridge can be further subdivided into smaller geomorphic or structural elements.
New Siberia is the easternmost of the Anzhu Islands, the northern subgroup of the New Siberian Islands lying between the Laptev Sea and East Siberian Sea. Its area of approximately 6,200 square kilometres places it the 102nd largest islands in the world. New Siberia Island is low lying, rising to only 76 metres and covered with tundra vegetation. The island is a part of the territory of Yakutia, Russia.
The Sandhills or Carolina Sandhills is a 10-35 mi wide physiographic region within the U.S. Atlantic Coastal Plain province, along the updip (inland) margin of this province in the states of North Carolina, South Carolina, and Georgia. The extent of the Carolina Sandhills is shown in maps of the ecoregions of North Carolina, South Carolina, and Georgia.
Blowouts are sandy depressions in a sand dune ecosystem (psammosere) caused by the removal of sediments by wind.
The Gran Desierto de Altar is one of the major sub-ecoregions of the Sonoran Desert, located in the State of Sonora, in northwest Mexico. It includes the only active erg dune region in North America. The desert extends across much of the northern border of the Gulf of California, spanning more than 100 kilometres (62 mi) east to west and over 50 kilometres (31 mi) north to south. It constitutes the largest continuous wilderness area within the Sonoran Desert.
The Fylde is a coastal plain in western Lancashire, England. It is roughly a 13-mile-long (21-kilometre) square-shaped peninsula, bounded by Morecambe Bay to the north, the Ribble estuary to the south, the Irish Sea to the west, and the foot of the Bowland hills to the east which approximates to a section of the M6 motorway and West Coast Main Line.
Matthias Kuhle was a German geographer and professor at the University of Göttingen. He edited the book series Geography International published by Shaker Verlag.
The Carolina Sandhills National Wildlife Refuge is a 45,348-acre (183.52 km2) national wildlife refuge (NWR) located in Chesterfield County, South Carolina. The refuge is managed by the U.S. Fish and Wildlife Service from a headquarters located in McBee, South Carolina. The refuge is served by U.S. Highway 1, which passes through it.
Old and Young Drift are geographic names given to the morainic landscapes that were formed in Central Europe; the Old Drift during the older ice ages and the Young Drift during the latest glaciations – the Weichselian in North Germany and the Würm in the Alps. Their landforms are quite different. Areas of Old Drift have been heavily flattened and transformed as a result of geomorphic processes such as denudation and erosion, whilst areas of Young Drift have largely retained their original shape. Whilst the majority of Old Drift moraines were formed during the Saale glaciation about 130,000 to 140,000 years ago, the Young Drift moraines in Central Europe are only about 15,000 to 20,000 years old. The terms Old and Young Drift are used for all elements of the glacial series even though the meltwater deposits and landforms are not strictly moraines.
Woods Bay State Park is a state park located near the town of Olanta in Florence County, South Carolina. The park contains some of the last remaining large Carolina Bays. Recent work by the U.S. Geological Survey has interpreted the Carolina Bays as relict thermokarst lakes that formed several thousands of years ago when the climate was colder, drier, and windier. Thermokarst lakes develop by thawing of frozen ground (permafrost) and by subsequent modification by wind and water. Thus, this interpretation suggests that permafrost once extended as far south as the Carolina Bays during the last ice age and (or) previous ice ages.
Little Pee Dee State Park is a state park located near the town of Dillon in Dillon County, South Carolina. The park land includes a part of a Carolina Bay and adjacent sand rim. Recent work by the U.S. Geological Survey has interpreted the Carolina Bays as relict thermokarst lakes that formed several thousands of years ago when the climate was colder, drier, and windier. Thermokarst lakes develop by thawing of frozen ground (permafrost) and by subsequent modification by wind and water. Thus, this interpretation suggests that permafrost once extended as far south as the Carolina Bays during the last ice age and (or) previous ice ages.
Lake Kankakee formed 14,000 years before present (YBP) in the valley of the Kankakee River. It developed from the outwash of the Michigan Lobe, Saginaw Lobe, and the Huron-Erie Lobe of the Wisconsin glaciation. These three ice sheets formed a basin across Northwestern Indiana. It was a time when the glaciers were receding, but had stopped for a thousand years in these locations. The lake drained about 13,000 YBP, until reaching the level of the Momence Ledge. The outcropping of limestone created an artificial base level, holding water throughout the upper basin, creating the Grand Kankakee Marsh.
Teri or Teri dune complex is a coastal landscape peculiar to some parts of Tamil Nadu mainly in southeastern India. The landscape consists of sediments dating to the Quaternary Period and made of marine deposits with aeolianite and characteristic red sand and silt dunes. These red soils are thought to have originated in the Pleistocene. Robert Bruce Foote hypothesized that these dunes were created by the action of winds (aeolian) lifting the fine silt fraction from further east. These dunes are oriented along the axis running parallel to the coast and between the latitudes of 8°00′ to 9°30′ N and longitudes 77°18′ to 79°00′ E. The soils also have calcium deposits replacing the old roots of vegetation. The soil is rich in ilmenite and the red colour is derived from haematite originating from garnet.
The Starczynów Desert is an area of formerly exposed but now largely overgrown sand dunes in the Silesian upland between Olkusz and Bukowno in the Malopolska Voivodeship, southern Poland. The desert takes its name from the former village of Starczynów, which was merged into Bukowno in 1958.
The Chinese Loess Plateau, or simply the Loess Plateau, is a plateau in north-central China formed of loess, a clastic silt-like sediment formed by the accumulation of wind-blown dust. It is located southeast of the Gobi Desert and is surrounded by the Yellow River. It includes parts of the Chinese provinces of Gansu, Shaanxi and Shanxi. The depositional setting of the Chinese Loess Plateau was shaped by the tectonic movement in the Neogene period, after which strong southeast winds caused by the East Asian Monsoon transported sediment to the plateau during the Quaternary period. The three main morphological types in the Loess Plateau are loess platforms, ridges and hills, formed by the deposition and erosion of loess. Most of the loess comes from the Gobi Desert and other nearby deserts. The sediments were transported to the Loess Plateau during interglacial periods by southeasterly prevailing winds and winter monsoon winds. After the deposition of sediments on the plateau, they were gradually compacted to form loess under the arid climate.
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