Look up loess in Wiktionary, the free dictionary.

Loess in Vicksburg, Mississippi, USA.

An outcrop of loess in Patagonia, Argentina.

Loess (/ˈloʊ.əs/, /ˈlʌs/, /ˈlɛs/, or UK /ˈlɜrs/) is an aeolian sediment formed by the accumulation of wind-blown silt, typically in the 20–50 micrometre size range, twenty percent or less clay and the balance equal parts sand and silt ^[1] that are 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.

The word loess, with connotations of origin by wind-deposited accumulation, is of German origin and means “loose.” It was first applied to Rhine River valley loess about 1821.^[2]

Properties[link]

Loess near Hunyuan, Shanxi province, China.

Loess is 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 crystals of quartz, feldspar, mica and other minerals. Loess can be described as a rich, dust-like soil.^[3]

Loess deposits may become very thick; more than a hundred metres in areas of China and the Midwestern United States. It generally occurs as a blanket deposit that covers areas of hundreds of square kilometres and tens of metres thick.

Loess often stands in either steep or vertical faces.^[4] 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 dunes has been explained by a combination of wind and tundra conditions.

Etymology[link]

Loess comes from the German Löss or Löß, and ultimately from Alemannic lösch meaning loose as named by peasants and masons along the Rhine Valley.

Formation[link]

Periglacial loess[link]

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 summer. During the fall 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 and clay, they were highly susceptible to winnowing of their silts and clays 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.^[5][6]

Non-glacial[link]

Non-glacial loess can originate from deserts, dune fields, playa lakes, and volcanic ash.

Some types of nonglacial loess are:^[7]

• Volcanic loess in Ecuador and Argentina.
• Tropical loess in Argentina, Brazil and Uruguay.
• Gypsum 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.^[8] The loess covering the Great Plains of Nebraska, Kansas, and Colorado is non-glacial desert loess. Non-glacial desert loess is also found in Australia.^[9] and Africa^[6]

Fertility[link]

Loess tends to develop into very rich soils. Under appropriate climatic conditions it is some of the most agriculturally productive terrain in the world.^[10]

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 very 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 (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 per square meter per year. Although in geological time loess has an incredible rate of erosion, in a more human time scale loess is durable and resistant to maltreatment. In China loess deposits along the Yellow River have been farmed and have produced phenomenal yields for over one thousand years. A large amount of the credit for this goes to the farmers; Chinese farmers were the first to practice active erosion control. The largest deposit of loess in the United States, 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 was farmed with mouldboard ploughs 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.

Sites[link]

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 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 consist of three layers. The Peoria Loess, Sicily Island Loess, and Crowley's Ridge Loess accumulated at different periods of time during the Pleistocene. 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 mastodons.^[11]

Loess soil forms sharp hills east of the Mississippi River and Yazoo River in western Mississippi north and south of Vicksburg. These deposits are more than 30 m thick (comparable to those in Iowa) immediately above the river valleys, to which they are sub-parallel, and thin to trace thickness within 40 km to the east. Streams and gulleys are incised very deeply and sharply between the linear loess ridges making topography very important in the conduct of military operations for the Vicksburg Campaign.

The Palouse Hills of eastern Washington and northern Idaho is a fertile agricultural region based on loess deposits.

Glacial loess from the Matanuska Glacier blown into Matanuska Valley created the fertile soil conditions that motivated the Matanuska Colony resettlement experiment in Alaska during the Great Depression.

The Loess Plateau (simplified Chinese: 黄土高原; traditional Chinese: 黃土高原; pinyin: huángtǔ gāoyuán), also known as the Huangtu Plateau, is a plateau that covers an area of some 640,000 km² in the upper and middle of China's Yellow River and China proper. The soil of this region has been called the "most highly erodible soil on earth".^[12] The Loess Plateau and its dusty soil cover almost all of Shanxi, Shaanxi, and Gansu provinces, the Ningxia Hui Autonomous Region, and parts of others.

Hungary has several areas that are covered by loess. At locations such as Dunaújváros and Balatonakarattya, loess walls are exposed as loess reefs. Similar formations exist in Romania (Wallachian Plain) and in Bulgaria on the south bank of the Danube.

Central Belgium is covered by thick loess stacks. Neanderthal artifacts were found within the soils between the loess layers of the Veldwezelt-Hezerwater.

Crowley's Ridge in Arkansas is a natural loess accumulation point.

See also[link]

• Loam
• Brickearth

References[link]

External links[link]

• 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, Leipzig, 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.
• Gill, T.E., A. Warren, and J.E. Stout, 2008, The Bibliography of Aeolian Research. Cropping Systems Research Laboratory, U.S. Department of Agriculture, Lubbock, Texas.
• Heinrich, P.V., 2008, Loess map of Louisiana., Public Information Series. no. 12, Louisiana Geological Survey, Baton Rouge, Louisiana.
• Prior, J.C., and D.J. Quade, nd, The Loess Hills: A Geologic View. Iowa Geological Survey, 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 Western Iowa
• The Loess Hills of Roztocze

John C. Liu 劉醇逸
Liu at the 2009 West Indian Day Parade.
New York City Comptroller
Incumbent
Assumed office January 1, 2010
Mayor	Michael Bloomberg
Preceded by	Bill Thompson
Member of the New York City Council from the 20th District
In office January 2002 – January 2010
Preceded by	Julia Harrison
Succeeded by	Peter Koo
Constituency	Queens: Flushing, Queensboro Hill, Mitchell Gardens, Kissena Park, Harding Heights, Auburndale; part of Whitestone
Personal details
Born	(1967-01-08) January 8, 1967 (age 45) Taiwan
Political party	Democratic
Spouse(s)	Jenny Liu
Children	Joey
Residence	Flushing, New York, United States
Alma mater	Binghamton University
Profession	Politician
Website	Office of the Comptroller

John Chun Liu (born January 8, 1967 in Taiwan) is a New York City elected official, currently serving as New York City Comptroller and running for the 2013 mayoral race. Liu previously served on the New York City Council representing District 20. He was elected to the City Council in 2001 to represent northeast Queens, and was re-elected in 2003 and 2005.

Liu entered the New York City Comptroller election in 2009 and won the race on November 3, 2009, becoming the first Asian American to be elected to a city-wide office in New York City.^[1][2] He was succeeded in the City Council by pharmacist Republican Peter Koo. Koo, along with Democrat Margaret Chin, a Council member from Manhattan, comprise the Asian-American delegation of the Council.^[3]

Liu's campaign fundraising practices are under investigation for violations of campaign finance law and possible use of foreign funds.^[4] Two individuals tied to the Liu campaign have been arrested on charges of wire fraud and obstruction of justice.^[5]

Biography[link]

At the age of five, he moved with his family to the United States from Taiwan. Chang F. Liu, his father, was a Master of Business Administration student and bank teller who worked 12 hour days.^[6] In honor of John F. Kennedy, Liu's father changed his sons' names to John, Robert, and Edward, and his own name to Joseph. Although both his parents spoke Chinese, Liu cannot speak it himself.^[7]

He attended PS 20 in Queens and the Bronx High School of Science to 1985,^[8][9] doing community organizing and volunteer work in his spare time.^[6]

He attended Binghamton University where he majored in Mathematical Physics and graduated in 1988.^[8] He worked as a manager at PricewaterhouseCoopers and served as President of the North Flushing Civic Association before his election to the City Council.^[8][10]

Liu is married to Jenny Liu, an engineer, and has one son, Joey. He resides in Flushing, near where he grew up.

Political career[link]

Elected to the New York City Council in 2001 to represent District 20, the northeast Queens area (Flushing, Queensboro Hill, Mitchell Linden, Murray Hill, Holly, Kissena Park, Harding Heights, Auburndale, part of Whitestone), Liu is the first Asian American to be elected to the City Council.^[6] He served as the Chairperson of the New York City Council's Transportation Committee and also served on the committees on Education, Consumer Affairs, Health, Land Use, Contracts, Oversight & Investigations and Lower Manhattan Redevelopment.^[11]

In March 2009, Liu announced that he was running for the post of New York City Comptroller.^[12] Liu has raised $3 million for his political run, more than his competitors. ^[13]

Beginning in May, Liu picked up several endorsements. The Village Independent Democrats,^[14] The Queens County Democratic organization,^[15] the local Americans for Democratic Action chapter^[16] and the Working Families Party,^[17] 1199 SEIU union local and the Uniformed Firefighters Association endorsed him.^[18] On September 1, the United Federation of Teachers endorsed Liu.

In the September 15 Democratic primary, Liu was the front-runner, ending up with 133,986 votes, or 38 percent of the vote. Because he did not manage to reach 40 of the vote, a run-off election was required between Liu and runner-up David Yassky, who received 30 percent of the vote in the primary.^[19] Two weeks later, Liu won the run-off by taking 55.6% of the vote against Yassky.^[20][21]

In the general election on November 3, Liu won the comptroller election with 76% of the vote, a total of 696,330 votes. Republican candidate Joseph Mendola came in second with 19.3% of the vote. After he was officially sworn in to the post, Liu became the first Asian American to hold a city-wide political office in New York City.^[1][2]

Asian Political Leadership Fund[link]

Liu is one of the leaders of the Asian Political Leadership Fund, a federally-designated 527 fund whose purpose is to promote political leadership from within the Asian American community.^[22]

Controversy[link]

Fundraising irregularities[link]

Investigations into the fundraising practices of Liu's election campaigns found numerous irregularities, including the use of straw donors and undisclosed bundling.^[23] A New York Times article in October 2011 documented several inconsistencies: after canvassing 100 households that were listed as having donated to the campaign, 24 irregularities were found, including donations from individuals who claimed they never donated, whose employers donated in their names, and several purported donors who did not appear to exist and could not be found.^[23] Campaign finance laws stipulate that each individual donor must fill out donor cards themselves, and that individuals who "bundle" donations must be disclosed. Liu's donor records, however, did not disclose the identity of bundlers, and included multiple instances where several donor cards were written by the same hand. Many of the irregularities in Liu's campaign were connected to the Chinese business community in Queens.^[23] In New York City, every dollar donated to a candidate is matched with $6 in taxpayer money.^[23]

Following publication of the New York Times article, the Federal Bureau of Investigation began investigating the irregularities in Liu's campaign.^[24] In November 17, 2011, one of Liu's fundraisers, 46-year-old Oliver Pan (潘心武, Pān Xīnwǔ), was arrested on charges of wire fraud from illegal donations.^[25][26] Pan was approached by an undercover FBI agent posing as someone who wanted to donate US$16,000 to Liu, which was over the city donation limit was only $4,950 for individual contributions.^[25] Pan then arranged for 20 fictitious donors to make donations to Liu's campaign with the money provided by the undercover FBI agent.^[26]

Initially in the first half of 2011 Liu has already received more than $1 million from fund raising contributions to his mayor run for supposedly 2013.^[25][27]

In light of the allegations of campaign finance fraud, Liu hired former state attorney general Robert Abrams to conduct a review of his campaign finances. However, in November 2011, Liu asked Abrams to suspend his inquiry in light of the ongoing FBI investigations. Abrams resigned on November 17.^[28]

In February 2012, a treasurer with the Liu campaign was arrested. 25-year-old Jenny (Jia) Hou was charged with using straw donors to circumvent campaign finance laws and gain more matching funds from taxpayers.^[29]

Foreign fundraising issue[link]

In late 2009, Manhattan federal prosecutors launched an investigation into the possibility that foreign money had flowed illegally into Liu's campaign for comptroller.^[4][28]

Pan is the president of a company called "Golden Arrow Property" (金箭房地產有限責公司).^[28] Oliver Pan's office is in 35 East Broadway, New York room 506 handles finance, banking, insurance and real estate.^[27] He also has an office in Mendham New Jersey.^[30] Some people in the Chinese community believe Liu is being framed.^[27] Pan's funding activities extended beyond Liu, as he was listed as a fundraiser for Hillary Clinton during the 2008 presidential campaign.^[30] Ru Mei-hua (盧美華 Lú Měihuá), director of planning for John Liu, helped him rise from a councilman 10 years ago to a major political force mainly connecting Liu to a network of Asian American businessmen in NY.^[31] She has been considered a key to understanding the fund raising details from donors, but denied requests to be interviewed.^[31]

See also[link]

• Government of New York City

References[link]

v t e New York City Comptrollers since the 1898 Consolidation Coler Grout Metz Pendergast Craig Berry McAneny Cunningham McGoldrick Taylor McGoldrick Joseph Gerosa Beame Procaccino Beame Goldin Holtzman Hevesi Thompson Liu

External links[link]

• Oliver Pan conspiracy to commit wire fraud complaints
• Animation on Donation controversy

External links[link]

Wikimedia Commons has media related to: John Liu

• Official New York City Comptroller Website
• Asian Political Leadership Fund