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60-498: The Loess Hills are a formation of wind-deposited loess soil in the westernmost parts of Iowa and Missouri , and the easternmost parts of Nebraska and Kansas , along the Missouri River . The Loess ( / ˈ l oʊ . ə s / , / ˈ l ʌ s / , or / ˈ l ɛ s / ) Hills are generally located between 1 and 15 miles (2 and 24 km) east of the Missouri River channel. The Loess Hills rise 200 feet (60 m) above

120-517: A characteristic yellow hue and is generally broken down into several units based on the period of deposition (Loveland, Pisgah, Peoria). Loess is known locally as "sugar clay" because it can be extremely hard when dry, but when wet, loses all cohesion. The Loess Hills of Iowa are remarkable for the depth of the drift layer, often more than 90 feet (27 m) deep. The only comparable deposits of loess to such an extent are located in Shaanxi , China . Today,

180-424: A height of 1–3 m (3.3–9.8 ft). The stem base turns blue or purple as it matures. Big bluestem blooms in the summer and seeds into the fall. The inflorescence (cluster of flowers) is a raceme of two to six, most commonly three, narrow spike -like racemes alternately arranged along the top of the stem. It somewhat resembles a wild turkey 's foot. Each raceme contains pairs of spikelets . Each pair has

240-426: A high cation exchange capacity (the ability of the soil to retain nutrients) and porosity (the air-filled space in the soil). The fertility of loess is not due to organic matter content, which tends to be rather low, unlike tropical soils which derive their fertility almost wholly from organic matter. Even well managed loess farmland can experience dramatic erosion of well over 2.5 kg/m per year. In China,

300-563: A hundred meters in areas of Northwestern China and tens of meters in parts of the Midwestern United States. Loesses generally occur as blanket deposits that cover hundreds of square kilometers. The deposits are often tens of meters thick. Loesses often have steep or vertical faces. Because the grains are angular, loesses will often stand in banks for many years without slumping . This type of soil has "vertical cleavage", and thus, it can be easily excavated to form cave dwellings, which

360-488: A persistent grassland biome . When the valuable A-horizon topsoil is eroded or degraded, the underlying loess soil is infertile, and requires the addition of fertilizer in order to support agriculture . The loess along the Mississippi River near Vicksburg, Mississippi , consists of three layers. The Peoria Loess , Sicily Island Loess , and Crowley's Ridge Loess accumulated at different periods of time during

420-629: A record count of 16,000 birds in one season in 2005. Broken Kettle Grasslands Preserve in the northern Loess Hills is home to Iowa's only population of nesting black-billed magpies and home to the last remaining known population of prairie rattlesnake in Iowa. The Loess Hills Scenic Byway affords many scenic views from Westfield, Iowa , and to Hamburg . While much of the landscape is held in private ownership, thousands of acres of public land exist in state and county parks, wildlife areas and preserves. The Nature Conservancy also owns several preserve areas in

480-512: A stalked spikelet with another stalkless spikelet at the base of the stalk. The stalkless spikelet usually has a fertile, perfect floret (with both female and male parts) and an awn (bristle), and the stalked spikelet is awnless, and is sterile or has a staminate (male) flower. Big bluestem is a mid- successional grass in prairie and other grassland ecosystems. It grows in tall, dense stands that can outcompete other plant species. The stands grow until disturbance interrupts their spread. It

540-516: Is a less developed park in the middle of the Loess Hills State Forest. It has 344 acres (1.4 km) including what was once the Mormon village of Preparation . Backpacking trails lead to hike-in campsites. Two major state parks anchor the north and south end of the range—Waubonsie in the south and Stone in the north, both offer camping and a variety of other amenities. Hitchcock Nature Center

600-613: Is a popular method of making human habitations in some parts of China. However, loesses can readily erode. In several areas of the world, loess ridges have formed that had been aligned with the prevailing winds during the last glacial maximum . These are called " paha ridges" in America and "greda ridges" in Europe. The formation of these loess dunes has been explained as a combination of wind and tundra conditions. The word loess , with connotations of origin by wind-deposited accumulation,

660-461: Is also found in Australia and Africa. Loess tends to develop into very rich soils. Under appropriate climatic conditions, it is some of the most agriculturally productive terrain in the world. Soils underlain by loess tend to be excessively drained. The fine grains weather rapidly due to their large surface area, making soils derived from loess rich. The fertility of loess soils is due largely to

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720-484: Is also known as brickearth . Non-glacial loess can originate from deserts , dune fields , playa lakes , and volcanic ash . Some types of nonglacial loess are: The thick Chinese loess deposits are non-glacial loess having been blown in from deserts in northern China. The loess covering the Great Plains of Nebraska , Kansas , and Colorado is considered to be non-glacial desert loess. Non-glacial desert loess

780-528: Is made up of loess soil. The word loess is derived from the German for "loose or crumbly." Loess A loess is a periglacial or aeolian (windborne) sediment, defined as an accumulation of 20% or less of clay with a balance of roughly equal parts sand and silt (with a typical grain size from 20 to 50 micrometers), often loosely cemented by calcium carbonate . Usually, they are homogeneous and highly porous and have vertical capillaries that permit

840-564: Is mainly deposited in plateau-like situations in the Danube basins , likely derived from the Danube River system. In south-western Europe, relocated loess derivatives are mostly restricted to the Ebro Valley and central Spain. The Loess Hills of Iowa owe their fertility to the prairie topsoils built by 10,000 years of post-glacial accumulation of organic-rich humus as a consequence of

900-628: Is operated by the Pottawattamie County Conservation Board and features a lodge with raptor viewing platform and observation tower, from which one has striking views of the Hills, the Missouri River valley, and the skyline of downtown Omaha, Nebraska . Hike-in camping is also available at this location. Two National Natural Landmarks are located in the Loess Hills. The Little Sioux/Smith Lake Site contains 2,980 acres (12 km) and

960-724: Is perhaps the best example of the unique topography produced by large deposits of loess soil. The 7,440-acre (30 km) Turin Site of the Loess Hills National Natural Landmark is located just outside Turin and also contains the Turin Man prehistoric archeological site. The Loess Hills have a rich archaeological heritage. The hills around Glenwood , in Mills County , were inhabited by the Glenwood culture , an eastern extension of

1020-418: Is shade intolerant and is adapted to fire . It is a host to larvae of several species of butterflies, including the arogos skipper , byssus skipper , cobweb skipper , common wood nymph , Delaware skipper , and dusted skipper . The larvae of the leaf beetle Diabrotica cristata feed on the roots and the adults visit the flowers of other species of prairie flowers. Many ants decorate their nests with

1080-747: The First transcontinental railroad . Loess soil also forms the Arikaree Breaks in northwest Kansas, and the Mississippi-Yazoo "Bluff Hills" near Vicksburg, Mississippi . A large region of Nebraska to the south and east of the Sandhills is covered with loess. Deep loess deposits are also found in the Rhine River valley in Germany . Crowley's Ridge in southeastern Missouri and northeastern and eastern Arkansas

1140-549: The Ningxia Hui Autonomous Region , and parts of others. Loess deposits of varying thickness (decimeter to several tens of meters) are widely distributed over the European continent. The northern European loess belt stretches from southern England and northern France to Germany, Poland and the southern Ukraine and deposits are characterized by strong influences of periglacial conditions. South-eastern European loess

1200-683: The Pleistocene . Ancient soils, called paleosols , have developed on the top of the Sicily Island Loess and Crowley's Ridge Loess. The lowermost loess, the Crowley's Ridge Loess, accumulated during the late Illinoian Stage . The middle loess, Sicily Island Loess, accumulated during the early Wisconsin Stage . The uppermost loess, the Peoria Loess in which the modern soil has developed, accumulated during

1260-520: The Sandhills of central Nebraska. In 1984, a previously undiscovered fern, the Prairie Moonwort, was discovered in the Hills and is thought to be endemic to the Hills. Common fauna of the modern Loess Hills include white-tail deer , coyote , wild turkey , badger , bobcat , red and gray fox , ringneck pheasant , bobwhite , and red-tailed hawk , some of which were introduced or encouraged by Euro-American settlers. Woodland species are also on

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1320-466: The last Ice Age , glaciers advanced into the middle of North America, grinding underlying rock into dust-like " glacial flour ." As temperatures warmed, the glaciers retreated and vast amounts of meltwater and sediment flooded the Missouri River Valley . The sediment was deposited on the flood plain, creating huge mud flats . When meltwaters receded, these mud flats were exposed. As they dried,

1380-664: The loess deposits which give the Yellow River its color have been farmed and have produced phenomenal yields for over one thousand years. Winds pick up loess particles contributing to the Asian Dust pollution problem. The largest deposit of loess in the United States which is the Loess Hills along the border of Iowa and Nebraska , has survived intensive farming and poor farming practices . For almost 150 years, this loess deposit

1440-551: The Austrian and Hungarian loess stratigraphy, respectively. Since the 1980s, thermoluminescence (TL), optically stimulated luminescence (OSL), and infrared stimulated luminescence (IRSL) dating have been available, providing the possibility for dating the time of loess (dust) depositions, i.e., the time elapsed since the last exposure of the mineral grains to daylight. During the past decade, luminescence dating has significantly improved by new methodological improvements, especially

1500-570: The Chicago region. The rust fungus Puccinia andropogonis forms black telia on the leaves. The grass and its variants are good forage for horses and cattle , and can also be cut and used for hay . The grass is high in protein. While not considered the highest quality native forage found in the United States, it has long been considered a desirable and ecologically important grass by cattle ranchers and rangeland ecologists. Big bluestem

1560-553: The Hills which are open to the public, including Broken Kettle Grasslands Preserve—the largest contiguous tract of native prairie left in Iowa. The Loess Hills State Forest is located in west-central Iowa in Harrison and Monona counties. It comprises four units totaling 10,600 acres (43 km), and offers hiking, backpacking, picnicking, and fishing opportunities. Preparation Canyon State Park, located near Pisgah in Monona County ,

1620-490: The Huangtu Plateau, is a plateau that covers an area of some 640,000 km around the upper and middle reaches of China's Yellow River . The Yellow River was so named because the loess forming its banks gave a yellowish tint to the water. The soil of this region has been called the "most highly erodible soil on earth". The Loess Plateau and its dusty soil cover almost all of Shanxi , Shaanxi , and Gansu provinces;

1680-462: The Loess Hills can rise over 350 feet (110 m) above the adjacent Missouri River floodplain. The Loess Hills have abundant oak-hickory hardwood forests and some of the last remaining stands of prairie grass in the region. The invasion of prairie and oak savanna areas by woodland species such as red cedar (not native to the Hills) is threatening the stability of the fragile soils, as well as diminishing

1740-564: The Mormon people to turn over all deeds and possessions to Thompson, who changed his name to "Father Ephraim". In 1856, the people asked for the return of their property; Thompson refused and they decided to lynch him. Thompson escaped the mob by hiding in an attic in Onawa . He then fled Iowa. On August 12, 1859, Abraham Lincoln ascended the hills at Cemetery Hill at Fairview Cemetery in Council Bluffs while being briefed on possible locations for

1800-795: The Nebraska Phase of the Woodland period . The Glenwood Culture lived in the area from roughly 900 A.D. to 1300 A.D. and built hundreds of earth lodges in the region, farming the rich valley bottoms and cultivating native plants from the surrounding hills. An earth lodge replica has been reconstructed in Glenwood Lake Park, and the Mills County Museum, also located at the park, houses an excellent collection of artifacts collected by renowned amateur archeologist Paul Rowe. The city of Council Bluffs, Iowa (originally "Kanesville") derives its name from

1860-556: The Rhine valley near Heidelberg . Charles Lyell (1834) brought the term into widespread usage, observing similarities between "loess" and its derivatives along the loess bluffs in the Rhine and in Mississippi . At the time, it was thought that the yellowish brown silt-rich sediment was of fluvial origin and had been deposited by large rivers. The aeolian origin of the loesses was recognized later (Virlet D'Aoust 1857), particularly due to

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1920-496: The autumn and winter, when the melting of the ice sheets and ice caps ceased, the flow of meltwater down these rivers either ceased or was greatly reduced. As a consequence, large parts of the formerly submerged and unvegetated floodplains of these braided rivers dried out and were exposed to the wind. Because the floodplains consist of sediment containing a high content of glacially ground flour-like silt and clay , they were highly susceptible to winnowing of their silts and clays by

1980-547: The best areas to view raptor migrations on the continent. As air masses move off the Great Plains, they sink into the Missouri River valley. The prevailing winds across the floodplain then hit the sharp rise of the Loess Hills, creating thermal updrafts that raptors use to make their way to and from breeding grounds. Raptors can often be viewed forming "kettles", where many birds will create a funnel-like formation as they utilize

2040-564: The convincing observations of loesses in China by Ferdinand von Richthofen (1878). A tremendous number of papers have been published since then, focusing on the formation of loesses and on loess/ paleosol (older soil buried under deposits) sequences as the archives of climate and environment change. These water conservation works have been carried out extensively in China, and the research of loesses in China has been ongoing since 1954. [33] Much effort

2100-407: The corrugated, sharply dissected bluffs we see today. The dominant features of this landscape are "peak and saddle" topography, "razor ridges" (narrow ridges, often less than 10 feet (3 m) wide, which fall off at near ninety-degree angles on either side for 60 feet (18 m) or more), and "cat-step" terraces (caused by the constant slumping and vertical shearing of the loess soil). The soil has

2160-459: The development of single aliquot regenerative (SAR) protocols (Murray & Wintle 2000) resulting in reliable ages (or age estimates) with an accuracy of up to 5 and 10% for the last glacial record. More recently, luminescence dating has also become a robust dating technique for penultimate and antepenultimate glacial loess (e.g. Thiel et al. 2011, Schmidt et al. 2011) allowing for a reliable correlation of loess/palaeosol sequences for at least

2220-433: The fine-grained silt was picked up by strong prevailing westerly winds . Huge dust clouds were moved and redeposited over broad areas. The heavier, coarser silt was deposited close to the Missouri River flood plain, forming vast dune fields. The dune fields were eventually stabilized by grass. Due to the erosive nature of loess soil and its ability to stand in vertical columns when dry, the stabilized dunes were eroded into

2280-571: The flat plains forming a narrow band running north–south 200 miles (320 km) along the Missouri River. These hills are the first rise in land beyond the floodplain , forming something of a "front range" for Iowa, and parts of Missouri and Nebraska adjacent to the Missouri River. The Loess land formations of Iowa extend north into South Dakota and is a feature of three state Parks in South Eastern South Dakota. Union Grove State Park, Newton Hills State Park and Blood Run State Park. During

2340-411: The formation of loess: a dust source, adequate wind energy to transport the dust, a suitable accumulation area, and a sufficient amount of time. Periglacial (glacial) loess is derived from the floodplains of glacial braided rivers that carried large volumes of glacial meltwater and sediments from the annual melting of continental ice sheets and mountain ice caps during the spring and summer. During

2400-655: The hills based on the Lewis and Clark first formal "council", or meeting, with Native Americans in 1804, although the meeting with the Oto and Missouri tribe actually took place on the Nebraska side of the Missouri River at Fort Atkinson . Sgt. Charles Floyd , the only fatality of the Lewis and Clark Expedition, is buried on a bluff in the Loess Hills in what is now Sioux City, Iowa . In 1853, Mormon elder Charles B. Thompson split off from

2460-566: The hills stretch from the Blood Run Site in South Dakota in the north to Mound City, Missouri in the south. Loess topography can be found at various points in extreme eastern portions of Nebraska and Kansas along the Missouri River valley, particularly near the Nebraska cities of Brownville , Rulo , Plattsmouth , Fort Calhoun , and Ponca , and the Iowa cities of Hamburg and Sidney. Southeastern South Dakota has three state parks that feature

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2520-399: The last decade. Historically, fauna also included American bison , prairie chicken , mule deer , elk , and gray wolf ; these were extirpated by the late nineteenth century. The Missouri River valley had historically been a major migration corridor for birds, however, the channelization of the river and destruction of wetlands has led to a marked decline. The corridor still boasts one of

2580-547: The last two interglacial/glacial cycles throughout Europe and the Northern Hemisphere (Frechen 2011). Furthermore, the numerical dating provides the basis for quantitative loess research applying more sophisticated methods to determine and understand high-resolution proxy data including the palaeodust content of the atmosphere, variations of the atmospheric circulation patterns and wind systems, palaeoprecipitation, and palaeotemperature. Besides luminescence dating methods,

2640-662: The late Wisconsin Stage. Animal remains include terrestrial gastropods and mastodons . Extensive areas of loess occur in New Zealand including the Canterbury Plains and on the Banks Peninsula . The basis of loess stratigraphy was introduced by John Hardcastle in 1890. Much of Argentina is covered by loess. Two areas of loess are usually distinguished in Argentina: the neotropical loess north of latitude 30° S and

2700-637: The loess formations: Union Grove State Park, Newton Hills State Park and Blood Run State Park, all of which are south of Sioux Falls. The Big Sioux River separates the South Dakota Loess Hills from the Iowa Loess Hills; in South Dakota, the Loess Hills follow the eastern edge of Brule Creek. The hills are usually no more than 200 feet (61 m) above the Missouri River bottoms. However, in some areas, such as Murray Hill in Harrison County, Iowa,

2760-460: The main wagon train to Utah . He initially led 50 to 60 Mormon families to Kanesville . Thompson and a few other men then chose an area called Monona ("peaceful valley"), where they founded the town of Preparation , named for "School of Preparation for the Life Beyond ." Realizing the valley's wealth as a farming region, Thompson used his newspaper to report a message "from a spirit" directing

2820-420: The native ecosystems found there. The areas of native prairie comprise big bluestem and little bluestem , Indian grass , sideoats grama , and forbs such as yucca , pasque flower and lead plant (false indigo). Many of the prairie species found in the Loess Hills are outside of their normal range of distribution, with plants like spiny-leafed yucca and prickly pear cactus being more common further west, in

2880-553: The neotropical loess. The pampean loess is sandy or made of silty sand. This article incorporates CC-BY-3.0 text from the reference "Loess in Europe: Guest Editorial". Andropogon gerardi Andropogon gerardi , commonly known as big bluestem , is a species of tall grass native to much of the Great Plains and grassland regions of central and eastern North America. It is also known as tall bluestem , bluejoint , and turkeyfoot . Andropogon gerardi

2940-512: The pampean loess. The neotropical loess is made of silt or silty clay. Relative to the pampean loess the neotropical loess is poor in quartz and calcium carbonate . The source region for this loess is thought by some scientists to be areas of fluvio-glacial deposits the Andean foothills formed by the Patagonian Ice Sheet . Other researchers stress the importance of volcanic material in

3000-624: The rise in the Loess Hills as the suppression of fire has led to an increase in habitat for forest-dwelling species. Fauna more typical of the pre-settlement Loess Hills, such as the prairie rattlesnake , great plains skink , plains pocket mouse , ornate box turtle and spadefoot toad , are becoming rare and even endangered due to habitat fragmentation as a result of increased development and suppression of fire in prairie remnants and oak savannas. Species such as bobcat have been rebounding, and mountain lions have been recorded in Southwest Iowa in

3060-481: The same thermal. Typical species found during the months from September to December include red-tailed hawk , sharp-shinned hawk , peregrine falcon , ferruginous hawk , Swainson's hawk , Cooper's hawk , osprey , northern harrier , American kestrel , and bald eagle . In all, 20 species of raptor have been identified in a single season since the Hitchcock Nature Center HawkWatch started, with

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3120-444: The sediment to fracture and form vertical bluffs . Loesses are homogeneous ; porous ; friable ; pale yellow or buff ; slightly coherent ; typically, non- stratified ; and often calcareous . Loess grains are angular , with little polishing or rounding, and composed of quartz , feldspar , mica , or other mineral crystals. Loesses have been described as rich, dust-like soil. Loess deposits may become very thick: at more than

3180-497: The seeds, including Formica glacialis , F. montana , and F. subsericea . Several species of ants, such as F. glacialis , F. montana , F. subsericea , Lasius minutus , and L. umbratus build nests around the base of this bunchgrass, forming large soil mounds. In larger mounds, the nest is shared by multiple species of ants, and is "likened to an apartment complex with each ant species in its own nest partition". Up to 12 species of ants have been recorded in mounds found in

3240-447: The specific epithet of this taxon. Andropogon gerardii still makes appearances in various literature, including other USDA publications. Big bluestem is a perennial warm-season bunchgrass . It is tolerant of a wide range of soil conditions. The main roots are 6–10 ft (1.8–3.0 m) deep, and the plants send out strong, tough rhizomes , so it forms very strong sod . Depending on soil and moisture conditions, it grows to

3300-506: The use of radiocarbon dating in loess has increased during the past decades. Advances in methods of analyses, instrumentation, and refinements to the radiocarbon calibration curve have made it possible to obtain reliable ages from loess deposits for the last 40–45 ka. However, the use of this method relies on finding suitable in situ organic material in deposits such as charcoal, seeds, earthworm granules, or snail shells. According to Pye (1995), four fundamental requirements are necessary for

3360-632: The wind. Once entrained by the wind, particles were then deposited downwind. The loess deposits found along both sides of the Mississippi River alluvial valley are a classic example of periglacial loess. During the Quaternary , loess and loess-like sediments were formed in periglacial environments on mid-continental shield areas in Europe and Siberia as well as on the margins of high mountain ranges like in Tajikistan and on semi-arid margins of some lowland deserts as in China. In England, periglacial loess

3420-451: Was formally named in 1792 by Fulgenzio Vitman . It was named for French botanist Louis Gérard , who had first described the plant from specimens that had been cultivated in Provence , France. Kew 's International Plant Names Index and USDA Germplasm Resources Information Network reject the spelling gerard ii and provide reasoning for gerard i as being the correct spelling for

3480-526: Was farmed with mouldboard ploughs and tilled in the fall, both intensely erosive practices. At times it suffered erosion rates of over 10 kilograms per square meter per year. Today this loess deposit is worked as low till or no till in all areas and is aggressively terraced . An area of multiple loess deposits spans from southern Tajikistan up to Almaty , Kazakhstan . The Loess Plateau ( simplified Chinese : 黄土高原 ; traditional Chinese : 黃土高原 ; pinyin : Huángtǔ Gāoyuán ), also known as

3540-563: Was introduced into English from the German Löss , which can be traced back to Swiss German and is cognate with the English word loose and the German word los . It was first applied to the Rhine River valley loesses around 1821. The term "Löß" was first described in Central Europe by Karl Cäsar von Leonhard (1823–1824), who had reported yellowish brown, silty deposits along

3600-407: Was put into setting up regional and local loess stratigraphies and their correlations (Kukla 1970, 1975, 1977). However, even the chronostratigraphical position of the last interglacial soil correlating with marine isotope substage 5e was a matter of debate, due to the lack of robust and reliable numerical dating, as summarized, for example, by Zöller et al. (1994) and Frechen et al. (1997) for

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