Loess (, ; from german: Löss ) is a
clastic, predominantly
silt
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 (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel ...
-sized
sediment
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand ...
that is formed by the accumulation of wind-blown
dust
Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian process), volcanic eruptions, and pollution. Dust in ...
.
Ten percent of Earth's land area is covered by loess or similar
deposits.
Loess is a
periglacial or
aeolian (windborne) sediment, defined as an accumulation of 20% or less of
clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4).
Clays develop plasticity when wet, due to a molecular film of water surrounding the clay pa ...
and a balance of roughly equal parts
sand
Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class ...
and silt (with a typical
grain size from 20 to 50 micrometers), often loosely cemented by
calcium carbonate. It is usually
homogeneous and highly
porous and is traversed by vertical capillaries that permit the sediment to fracture and form vertical
bluffs.
Properties
Loess is
homogeneous,
porous,
friable, pale yellow or
buff
Buff or BUFF may refer to:
People
* Buff (surname), a list of people
* Buff (nickname), a list of people
* Johnny Buff, ring name of American world champion boxer John Lisky (1888–1955)
* Buff Bagwell, a ring name of American professional w ...
, slightly
coherent
Coherence, coherency, or coherent may refer to the following:
Physics
* Coherence (physics), an ideal property of waves that enables stationary (i.e. temporally and spatially constant) interference
* Coherence (units of measurement), a deriv ...
, typically non-
stratified
Stratification may refer to:
Mathematics
* Stratification (mathematics), any consistent assignment of numbers to predicate symbols
* Data stratification in statistics
Earth sciences
* Stable and unstable stratification
* Stratification, or st ...
and often
calcareous
Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines.
In zoology
''Calcareous'' is used as an ad ...
. Loess grains are
angular, with little polishing or rounding, and composed of crystals of
quartz
Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical f ...
,
feldspar
Feldspars are a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) felds ...
,
mica and other
mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...
s. Loess can be described as a rich, dust-like soil.
Loess deposits may become very thick, more than a hundred meters in areas of Northwestern China and tens of meters in parts of the Midwestern United States. Loess generally occurs as a blanket deposit that covers areas of hundreds of square kilometers. The deposits are often tens of meters thick. Loess often stands in either steep or vertical faces. Because the grains are angular, loess will often stand in banks for many years without
slumping. This soil has a characteristic called vertical cleavage which makes it easily excavated to form cave dwellings, a popular method of making
human habitations in some parts of China. Loess will erode very readily.
In several areas of the world, loess
ridges have formed that are aligned with the
prevailing winds during the last
glacial maximum. These are called "
paha ridges" in America and "greda ridges" in Europe. The form of these loess
dune
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, f ...
s has been explained by a combination of wind and
tundra conditions.
Etymology
The word ''loess'', with connotations of origin by wind-deposited accumulation, came into English from
German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ge ...
''Löss'', which can be traced back to
Swiss German and is
cognate
In historical linguistics, cognates or lexical cognates are sets of words in different languages that have been inherited in direct descent from an etymological ancestor in a common parent language. Because language change can have radical ef ...
with the English word ''loose'' and the German word ''los''. It was first applied to Rhine River valley loess about 1821.
History of research
The term "Löß" was first described in
Central Europe
Central Europe is an area of Europe between Western Europe and Eastern Europe, based on a common historical, social and cultural identity. The Thirty Years' War (1618–1648) between Catholicism and Protestantism significantly shaped the a ...
by
Karl Cäsar von Leonhard
Karl Cäsar von Leonhard (12 September 1779 in Rumpenheim – 23 January 1862 in Heidelberg) was a German mineralogist and geologist. His son, Gustav von Leonhard, was also a mineralogist.
From 1797 he studied at the universities of Marburg and ...
(1823–1824) who reported yellowish brown, silty deposits along the Rhine valley near
Heidelberg
Heidelberg (; Palatine German: ') is a city in the German state of Baden-Württemberg, situated on the river Neckar in south-west Germany. As of the 2016 census, its population was 159,914, of which roughly a quarter consisted of students ...
.
Charles Lyell (1834) brought this term into widespread usage by observing similarities between loess and loess derivatives along the loess bluffs in the Rhine and Mississippi.
At that time it was thought that the yellowish brown silt-rich sediment was of
fluvial origin being deposited by the large rivers.
It was not until the end of the 19th century that the
aeolian origin of loess was recognized (Virlet D'Aoust 1857), especially the convincing observations of loess in China by
Ferdinand von Richthofen (1878).
A tremendous number of papers have been published since then, focusing on the formation of loess and on loess/
paleosol (older soil buried under deposits) sequences as archives of climate and environment change.
These water conservation works were carried out extensively in China and the research of loess in China has been continued since 1954. (Liu TS, Loess and the environment)
Much effort was put into the setting up of regional and local loess
stratigraphies and their correlation (Kukla 1970, 1975, 1977). But even the chronostratigraphical position of the last interglacial soil correlating to marine
isotope
Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers ( mass num ...
substage 5e has been a matter of debate, owing to the lack of robust and reliable numerical dating, as summarized for example in Zöller et al. (1994) and Frechen, Horváth & Gábris (1997) for the Austrian and Hungarian loess stratigraphy, respectively.
Since the 1980s,
thermoluminescence
Thermoluminescence is a form of luminescence that is exhibited by certain crystalline materials, such as some minerals, when previously absorbed energy from electromagnetic radiation or other ionizing radiation is re-emitted as light upon h ...
(TL),
optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL) dating are available providing the possibility for dating the time of loess (dust) deposition, i.e. the time elapsed since the last exposure of the mineral grains to daylight.
During the past decade,
luminescence dating
Luminescence dating refers to a group of methods of determining how long ago mineral grains were last exposed to sunlight or sufficient heating. It is useful to geologists and archaeologists who want to know when such an event occurred. It uses var ...
has significantly improved by new methodological improvements, especially 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 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, such as the palaeodust content of the atmosphere, variations of the atmospheric circulation patterns and wind systems, palaeoprecipitation and palaeotemperature.
Besides luminescence dating methods, 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 enabled 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.
Formation
According to Pye (1995), four fundamental requirements are necessary for 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 loess
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 icesheets and mountain icecaps during the spring and summer. During the autumn and winter, when melting of the icesheets and icecaps 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 these floodplains consist of sediment containing a high content of glacially ground flour-like
silt
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 (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel ...
and
clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4).
Clays develop plasticity when wet, due to a molecular film of water surrounding the clay pa ...
, they were highly susceptible to winnowing of their silts and
clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4).
Clays develop plasticity when wet, due to a molecular film of water surrounding the clay pa ...
s by 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, on the margins of high mountain ranges like in
Tajikistan
Tajikistan (, ; tg, Тоҷикистон, Tojikiston; russian: Таджикистан, Tadzhikistan), officially the Republic of Tajikistan ( tg, Ҷумҳурии Тоҷикистон, Jumhurii Tojikiston), is a landlocked country in Centr ...
and on semi-arid margins of some lowland deserts like in China.
In England, periglacial loess is also known as
brickearth.
Non-glacial
Non-glacial loess can originate from
deserts,
dune fields,
playa lakes, and
volcanic ash
Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer ...
.
Some types of nonglacial loess are:
*
Desert loess produced by aeolian attrition of quartz grains;
*
Volcanic
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plat ...
loess in Ecuador and Argentina;
*
Tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
loess in Argentina, Brazil and Uruguay;
*
Gypsum
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywa ...
loess in Spain;
*
Trade wind loess in Venezuela and Brazil;
*
Anticyclonic loess in Argentina.
The thick Chinese loess deposits are non-glacial loess having been blown in from deserts in northern China. The loess covering the
Great Plains
The Great Plains (french: Grandes Plaines), sometimes simply "the Plains", is a broad expanse of flatland in North America. It is located west of the Mississippi River and east of the Rocky Mountains, much of it covered in prairie, steppe, a ...
of
Nebraska
Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the sout ...
,
Kansas
Kansas () is a U.S. state, state in the Midwestern United States, Midwestern United States. Its Capital city, capital is Topeka, Kansas, Topeka, and its largest city is Wichita, Kansas, Wichita. Kansas is a landlocked state bordered by Nebras ...
, and
Colorado
Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of the ...
is considered to be non-glacial desert loess.
Non-glacial desert loess is also found in Australia and Africa.
Fertility
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
Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmosphere, the ...
rapidly due to their large surface area, making soils derived from loess rich. One theory states that the fertility of loess soils is due largely to
cation exchange capacity (the ability of plants to absorb nutrients from the soil) and
porosity
Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measur ...
(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
Agricultural land is typically land ''devoted to'' agriculture, the systematic and controlled use of other forms of lifeparticularly the rearing of livestock and production of cropsto produce food for humans. It is generally synonymous with bo ...
can experience dramatic
erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is d ...
of well over 2.5 kg /m
2 per year. In China 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, the
Loess Hills
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.
Geology
The Loess (, , or ) Hills are generally located ...
along the border of
Iowa
Iowa () is a U.S. state, state in the Midwestern United States, Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wiscon ...
and Nebraska, has survived
intensive farming and
poor farming practices. For almost 150 years, this loess deposit was farmed with
mouldboard plough
A plough or plow ( US; both ) is a farm tool for loosening or turning the soil before sowing seed or planting. Ploughs were traditionally drawn by oxen and horses, but in modern farms are drawn by tractors. A plough may have a wooden, iron or ...
s and fall tilled, both intensely erosive. 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.
Large areas of loess deposits and soils
Central Asia
From southern
Tajikistan
Tajikistan (, ; tg, Тоҷикистон, Tojikiston; russian: Таджикистан, Tadzhikistan), officially the Republic of Tajikistan ( tg, Ҷумҳурии Тоҷикистон, Jumhurii Tojikiston), is a landlocked country in Centr ...
up to
Almaty
Almaty (; kk, Алматы; ), formerly known as Alma-Ata ( kk, Алма-Ата), is the largest city in Kazakhstan, with a population of about 2 million. It was the capital of Kazakhstan from 1929 to 1936 as an autonomous republic as part of ...
,
Kazakhstan
Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
, spans an area of multiple loess deposits.
East Asia
China
The
Loess Plateau (), also known as the Huangtu Plateau, is a
plateau
In geology and physical geography, a plateau (; ; ), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. Often one or more sides ...
that covers an area of some 640,000 km
2 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
Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former ...
cover almost all of
Shanxi,
Shaanxi
Shaanxi (alternatively Shensi, see § Name) is a landlocked province of China. Officially part of Northwest China, it borders the province-level divisions of Shanxi (NE, E), Henan (E), Hubei (SE), Chongqing (S), Sichuan (SW), Gansu (W), N ...
, and
Gansu provinces, the
Ningxia Hui Autonomous Region, and parts of others.
Europe
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 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.
North America
United States
The
Loess Hills
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.
Geology
The Loess (, , or ) Hills are generally located ...
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 a persistent
grassland
A grassland is an area where the vegetation is dominated by grasses ( Poaceae). However, sedge ( Cyperaceae) and rush ( Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur na ...
biome
A biome () is a biogeographical unit consisting of a biological community that has formed in response to the physical environment in which they are found and a shared regional climate. Biomes may span more than one continent. Biome is a broader ...
. When the valuable
A-horizon topsoil is eroded or degraded, the underlying loess soil is infertile, and requires the addition of
fertilizer
A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...
in order to support
agriculture
Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people ...
.
The loess along the
Mississippi River
The Mississippi River is the List of longest rivers of the United States (by main stem), second-longest river and chief river of the second-largest Drainage system (geomorphology), drainage system in North America, second only to the Hudson B ...
near
Vicksburg,
Mississippi
Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Miss ...
, consist of three layers. The ''Peoria Loess'', ''Sicily Island Loess'', and ''Crowley's Ridge Loess'' accumulated at different periods of time during the
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
. Ancient soils, called
paleosols, have developed in 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 early
Wisconsin Stage. The uppermost loess, the Peoria Loess, in which the modern soil has developed, accumulated during the late Wisconsin Stage. Animal remains include terrestrial
gastropods and
mastodon
A mastodon ( 'breast' + 'tooth') is any proboscidean belonging to the extinct genus ''Mammut'' (family Mammutidae). Mastodons inhabited North and Central America during the late Miocene or late Pliocene up to their extinction at the end of the ...
s.
[Miller, B.J., G.C. Lewis, J.J. Alford, and W.J. Day, 1985]
''Loesses in Louisiana and at Vicksburg, Mississippi. Guidebook, Friends of the Pleistocene Field Trip, 12-14 April, 1985.''
LA Agricultural Experimental Station, Louisiana State University
Louisiana State University (officially Louisiana State University and Agricultural and Mechanical College, commonly referred to as LSU) is a public land-grant research university in Baton Rouge, Louisiana. The university was founded in 1860 n ...
, Baton Rouge, Louisiana
Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is bord ...
. 126 pp.
Oceania
New Zealand
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
John Hardcastle (21 January 1847 – 12 June 1927) was a New Zealand amateur scientist, and pioneer in the study of paleoclimatology.
Hardcastle was born in Wakefield, Yorkshire, England in 1847. He moved with his family to New Zealand in 1858. ...
in 1890.
[*Hardcastle, J. 1890. On the Timaru loess as a climate register. Transcations & Proceedings of the New Zealand Institute 23, 324-332 (on line: Royal Society of New Zealand http://rsnz.natlib.govt.nz; reproduced in Loess Letter supplement 23, November 1988).]
South America
Argentina
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 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
Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical f ...
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 the neotropical loess.[
The pampean loess is sandy or made of silty sand.]
See also
* – North German loess regions
* – South German loess regions
*
References
; Attribution
This article incorporates CC-BY-3.0 text from the reference "Loess in Europe: Guest Editorial".
Further reading
* Smalley, I. J. (editor) 1975. ''Loess Lithology & Genesis''. Benchmark Geology 26. Dowden, Hutchinson & Ross 454pp.
* Smalley, I. J. 1980. ''Loess: A Partial Bibliography''. Geobooks/Elsevier. . 103pp.
* Rozycki, S. Z. 1991. ''Loess and Loess-like Deposits''. Ossolineum Wroclaw . 187pp.
External links
* 2006
''The Secret of China’s Vast Loess Plateau''
Suburban Emergency Management Project, Chicago, Illinois.
* 2007
''New European Loess Map.''
Helmholtz Centre for Environmental Research
The work of the Helmholtz Centre for Environmental Research – UFZ (prior to 28 November 2006 UFZ-Umweltforschungszentrum Leipzig-Halle GmbH) covers both basic research and applied research.
The UFZ was established on 12 December 1991. The Cent ...
, Leipzig
Leipzig ( , ; Upper Saxon: ) is the most populous city in the German state of Saxony. Leipzig's population of 605,407 inhabitants (1.1 million in the larger urban zone) as of 2021 places the city as Germany's eighth most populous, as ...
, Germany.
''Glacial Deposits: Loess and Till.''
Illinois State Museum, Springfield, Illinois.
* Briedis. C.A., 2006
''Loess Thickness Map (of Illinois).''
Illinois State Geological Survey, Champaign, Illinois
Champaign ( ) is a city in Champaign County, Illinois, United States. The population was 88,302 at the 2020 census. It is the tenth-most populous municipality in Illinois and the fourth most populous city in Illinois outside the Chicago metrop ...
.
* Heinrich, P.V., 2008
''Loess map of Louisiana.''
Public Information Series. no. 12, Louisiana Geological Survey The Louisiana Geological Survey is a state geological survey established by the Louisiana legislature by Act 131 in 1934 to serve the citizens Louisiana by collecting, preserving, and disseminating impartial information on the geomorphology, hydrog ...
, Baton Rouge, Louisiana
Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is bord ...
.
* Prior, J.C., and D.J. Quade, nd
''The Loess Hills: A Geologic View.''
Iowa Geological Survey
Iowa () is a U.S. state, state in the Midwestern United States, Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wiscon ...
, Department of Natural Resources, Iowa City, Iowa.
* U.S. Geological Survey, 1999
''Geology of the Loess Hills, Iowa''
* U.S. Geological Survey, 2006
''Eolian History of North America''
Why is loess important to study?
''The Loess Hills of Roztocze in Poland''
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Pedology
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Sedimentary rocks
Sediments
Types of soil
Aeolian landforms