Boulder

In geology, a boulder is a rock fragment with size greater than 25.6 centimetres (10.1 in) in diameter.[1] Smaller pieces are called cobbles and pebbles. While a boulder may be small enough to move or roll manually, others are extremely massive.[2] In common usage, a boulder is too large for a person to move. Smaller boulders are usually just called rocks or stones. The word boulder is short for boulder stone, from Middle English bulderston or Swedish bullersten.[3]

In places covered by ice sheets during Ice Ages, such as Scandinavia, northern North America, and Siberia, glacial erratics are common. Erratics are boulders picked up by ice sheets during their advance, and deposited when they melt.[2] They are called "erratic" because they typically are of a different rock type than the bedrock on which they are deposited. One of them is used as the pedestal of the Bronze Horseman in Saint Petersburg, Russia.

Some noted rock formations involve giant boulders exposed by erosion, such as the Devil's Marbles in Australia's Northern Territory, the Horeke basalts in New Zealand, where an entire valley contains only boulders, and The Baths on the island of Virgin Gorda in the British Virgin Islands.

Boulder-sized clasts are found in some sedimentary rocks, such as coarse conglomerate and boulder clay.

The climbing of large boulders is called bouldering.

Balanced Rock
This balancing boulder, "Balanced Rock" stands in Garden of the Gods park in Colorado Springs, Colorado, United States.
Devonian conglomerate on Conic Hill
Devonian conglomerate in Scotland with clasts up to boulder in size

See also

References

  1. ^ Neuendorf, K.K.E.; Mehl, Jr., J.P.; Jackson, J.A. (editors) (2005). Glossary of Geology (5th edition). Alexandria, Virginia: American Geological Institute. p. 79. ISBN 978-0922152896.CS1 maint: Extra text: authors list (link)
  2. ^ a b "Boulder". Dictionary.com. Retrieved 24 August 2013.
  3. ^ boulder. (n.d.) Online Etymology Dictionary. Retrieved December 9, 2011, from Dictionary.com website.

External links

Media related to Boulders at Wikimedia Commons

Boulder, Colorado

Boulder () is the home rule municipality that is the county seat and the most populous municipality of Boulder County, Colorado, United States. It is the state's 11th-most-populous municipality; Boulder is located at the base of the foothills of the Rocky Mountains at an elevation of 5,430 feet (1,655 m) above sea level. The city is 25 miles (40 km) northwest of Denver.The population of the City of Boulder was 97,385 people at the 2010 U.S. Census, while the population of the Boulder, CO Metropolitan Statistical Area was 294,567. Boulder is known for its association with gold seekers and for being the home of the main campus of the University of Colorado, the state's largest university. The city frequently receives high rankings in art, health, well-being, quality of life, and education.

Boulder City, Nevada

Boulder City is a city in Clark County, Nevada. It is approximately 26 miles (42 km) southeast of Las Vegas. As of the 2010 census, the population of Boulder City was 15,023.The community took its name from Boulder Canyon. Boulder City is one of only two cities in Nevada that prohibits gambling (the other being Panaca).

Boulder County, Colorado

Boulder County is one of the 64 counties of the U.S. state of Colorado of the United States. As of the 2010 census, the population was 294,567. The most populous municipality in the county and the county seat is Boulder.Boulder County comprises the Boulder, CO Metropolitan Statistical Area, which is included in the Denver-Aurora, CO Combined Statistical Area.

Bouldering

Bouldering is a form of rock climbing that is performed on small rock formations or artificial rock walls, known as boulders, without the use of ropes or harnesses. While it can be done without any equipment, most climbers use climbing shoes to help secure footholds, chalk to keep their hands dry and provide a firmer grip, and bouldering mats to prevent injuries from falls. Unlike free solo climbing, which is also performed without ropes, bouldering problems (the sequence of moves that a climber performs to complete the climb) are usually less than 6 meters (20 ft.) tall. Traverses, which are a form of boulder problem, require the climber to climb horizontally from one end to another. Artificial climbing walls allow boulderers to train indoors in areas without natural boulders. In addition, Bouldering competitions take place in both indoor and outdoor settings.The sport originally was a method of training for roped climbs and mountaineering, so climbers could practice specific moves at a safe distance from the ground. Additionally, the sport served to build stamina and increase finger strength. Throughout the 1900s, bouldering evolved into a separate discipline. Individual problems are assigned ratings based on difficulty. Although there have been various rating systems used throughout the history of bouldering, modern problems usually use either the V-scale or the Fontainebleau scale.

The growing popularity of bouldering has caused several environmental concerns, including soil erosion and trampled vegetation as climbers hike off-trail to reach bouldering sites. This has caused some landowners to restrict access or prohibit bouldering altogether.

Death of JonBenét Ramsey

JonBenét Patricia Ramsey (; August 6, 1990 – December 25, 1996) was an American child beauty queen who was killed at the age of 6 in her family's home in Boulder, Colorado. A lengthy handwritten ransom note was found in the house. Her father John found the girl's body in the basement of their house about eight hours after she had been reported missing. She sustained a broken skull from a blow to the head and had been strangled; a garrote was found tied around her neck. The autopsy report stated that the official cause of death was "asphyxia by strangulation associated with craniocerebral trauma."Her death was ruled a homicide. The case generated nationwide public and media interest, in part because her mother Patsy Ramsey (herself a former beauty queen) had entered JonBenét into a series of child beauty pageants. The crime is still unsolved and remains an open investigation with the Boulder Police Department.

The police initially suspected that the ransom note had been written by JonBenét's mother, and that the note and appearance of the child's body had been staged by her parents in order to cover up the crime. However, in 1998, the District Attorney said that due to a new DNA analysis, none of the immediate family members were under suspicion for the crime. Also in 1998, the police and the DA both said that JonBenét's brother Burke, who was nine years old at the time of her death, was not a suspect. The Ramseys gave several televised interviews but resisted police questioning except on their own terms. In October 2013, unsealed court documents revealed that a 1999 grand jury had recommended filing charges against JonBenét's parents for permitting the child to be in a threatening situation. John and Patsy were also accused of hindering the prosecution of an unidentified person who had "committed ... the crime of murder in the first degree and child abuse resulting in death". However, the DA determined that there was insufficient evidence to pursue a successful indictment.In 2002, the DA's successor took over investigation of the case from the police and primarily pursued an alternative theory that an intruder had committed the killing. In 2003, trace DNA that was taken from the victim's clothes was found to belong to an unknown male; each of the family's DNA had been excluded from this match. The DA sent the Ramseys a letter of apology in 2008, declaring the family "completely cleared" by the DNA results. In February 2009, the Boulder police took the case back from the DA and reopened the investigation.Media coverage of the case has focused on JonBenét's brief beauty pageant career, as well as her parents' wealth and the unusual evidence found in the case. Media reports questioned how the police handled the case. Ramsey family members and their friends have filed defamation suits against several media organizations.

Eldorado Canyon State Park

Eldorado Canyon State Park is part of the Colorado State Park system. It is located in Boulder County near the city of Boulder. The park consists of two areas, the Inner Canyon (developed area) and Crescent Meadows (undeveloped area). The park encompasses 885 acres (3.6 km2) with a variety of recreation opportunities available. Eldorado Canyon is home to one of the world's most accessible and comprehensive rock climbing areas. This state park is open during daylight hours only, visitors are expected to leave before dusk. A fee is required for entry, except on Colorado Day (August 1) when all state parks are free.

Erie, Colorado

The Town of Erie is a Statutory Town in Boulder and Weld counties in the U.S. state of Colorado. The population as of the 2010 census was 18,135, up from 6,291 at the 2000 census. Erie is located just west of Interstate 25, with easy access to Interstate 70, Denver International Airport and Colorado's entire Front Range. Erie's Planning Area spans 48 square miles (120 km2), extending from the north side of State Highway 52 south to State Highway 7, and between US 287 on the west and Interstate 25 to the east. Erie is approximately 35 minutes from Denver International Airport, 25 minutes from Denver and 20 minutes from Boulder.

The town was named after Erie, Pennsylvania, the former home of an early settler, Richard Van Valkenburg.

Glacial erratic

A glacial erratic is a piece of rock that differs from the size and type of rock native to the area in which it rests. "Erratics" take their name from the Latin word errare (to wander), and are carried by glacial ice, often over distances of hundreds of kilometres. Erratics can range in size from pebbles to large boulders such as Big Rock (15,000 tonnes or 17,000 short tons) in Alberta.

Geologists identify erratics by studying the rocks surrounding the position of the erratic and the composition of the erratic itself. Erratics are significant because:

They can be transported by glaciers, and they are thereby one of a series of indicators which mark the path of prehistoric glacier movement. Their lithographic origin can be traced to the parent bedrock, allowing for confirmation of the ice flow route.

They can be transported by ice rafting. This allows quantification of the extent of glacial flooding resulting from ice dam failure which release the waters stored in proglacial lakes such as Lake Missoula. Erratics released by ice-rafts that were stranded and subsequently melt, dropping their load, allow characterization of the high-water marks for transient floods in areas like temporary Lake Lewis.

Erratics dropped by icebergs melting in the ocean can be used to track Antarctic and Arctic-region glacial movements for periods prior to record retention. Also known as dropstones, these can be correlated with ocean temperatures and levels to better understand and calibrate models of the global climate.

Hoover Dam

Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Nevada and Arizona. It was constructed between 1931 and 1936 during the Great Depression and was dedicated on September 30, 1935, by President Franklin D. Roosevelt. Its construction was the result of a massive effort involving thousands of workers, and cost over one hundred lives. Originally known as Boulder Dam from 1933, it was officially renamed Hoover Dam, for President Herbert Hoover, by a joint resolution of Congress in 1947.

Since about 1900, the Black Canyon and nearby Boulder Canyon had been investigated for their potential to support a dam that would control floods, provide irrigation water and produce hydroelectric power. In 1928, Congress authorized the project. The winning bid to build the dam was submitted by a consortium called Six Companies, Inc., which began construction of the dam in early 1931. Such a large concrete structure had never been built before, and some of the techniques were unproven. The torrid summer weather and lack of facilities near the site also presented difficulties. Nevertheless, Six Companies turned the dam over to the federal government on March 1, 1936, more than two years ahead of schedule.

Hoover Dam impounds Lake Mead, the largest reservoir in the United States by volume (when it is full). The dam is located near Boulder City, Nevada, a municipality originally constructed for workers on the construction project, about 30 mi (48 km) southeast of Las Vegas, Nevada. The dam's generators provide power for public and private utilities in Nevada, Arizona, and California. Hoover Dam is a major tourist attraction; nearly a million people tour the dam each year. The heavily traveled U.S. Route 93 (US 93) ran along the dam's crest until October 2010, when the Hoover Dam Bypass opened.

Kalgoorlie

Kalgoorlie-Boulder, known colloquially as just Kalgoorlie, is a city in the Goldfields-Esperance region of Western Australia, located 595 km (370 mi) east-northeast of Perth at the end of the Great Eastern Highway. The city was founded in 1889 by the amalgamation of the towns of Kalgoorlie and Boulder, which developed in 1893 during the Coolgardie gold rush, on Western Australia's "Golden Mile". It is also the ultimate destination of the Goldfields Water Supply Scheme and the Golden Pipeline Heritage Trail.

At June 2018, Kalgoorlie-Boulder had an estimated urban population of 29,849, a decline from the recent peak of 32,966 in 2013.The name Kalgoorlie is derived from the Wangai word Karlkurla or Kulgooluh, meaning "place of the silky pears".

Lafayette, Colorado

The City of Lafayette () is a Home Rule Municipality located in Boulder County, Colorado, United States. The city population was 24,453 at the 2010 United States Census.

Longmont, Colorado

Longmont is a Home Rule Municipality in Boulder and Weld counties of the U.S. state of Colorado. Longmont is located northeast of the county seat of Boulder and 33 miles (53 km) north-northwest of the Colorado State Capitol in Denver.

Longmont's population was 86,270 at the time of the 2010 U.S. Census. Longmont is the 13th most populous city in the state of Colorado.

The word "Longmont" comes from Longs Peak, a prominent mountain named for explorer Stephen H. Long that is clearly visible from Longmont, and "mont", from the French word "montagne" for mountain.

Louisville, Colorado

Louisville () is a home rule municipality in Boulder County, Colorado, United States. The city population was 18,376 at the 2010 United States Census. Louisville began as a rough mining community in 1877, suffered through a period of extraordinary labor violence early in the 20th century, and then, when the mines closed in the 1950s, made a transition to a suburban residential community. CNN/Money and Money magazine have consistently listed Louisville as one of the 100 best places to live in the United States, ranking it among the top 100 in 2007, 2009 2011, 2013, 2015, and 2017.

Scree

Scree is a collection of broken rock fragments at the base of crags, mountain cliffs, volcanoes or valley shoulders that has accumulated through periodic rockfall from adjacent cliff faces. Landforms associated with these materials are often called talus deposits. Talus deposits typically have a concave upwards form, while the maximum inclination corresponds to the angle of repose of the mean debris size.

The term scree comes from the Old Norse term for landslide, skriða, while the term talus is a French word meaning a slope or embankment.

Superior, Colorado

Superior is a Statutory Town in Boulder County in the U.S. state of Colorado, with a small, uninhabited segment of land area extending into Jefferson County . According to the 2010 census, the population of the city was 12,483.

The Stand

The Stand is a post-apocalyptic horror/fantasy novel by American author Stephen King. It expands upon the scenario of his earlier short story "Night Surf" and presents a detailed vision of the total breakdown of society after the accidental release of a strain of influenza that had been modified for biological warfare causes an apocalyptic pandemic, killing off over 99% of the world's population. Published in 1978, The Stand is the fourth and longest novel he published. The Stand is a book dedicated to King's wife, Tabitha King.

University of Colorado

The University of Colorado system is a system of public universities in Colorado consisting of four campuses: University of Colorado Boulder, University of Colorado Colorado Springs, University of Colorado Denver in downtown Denver and at the Anschutz Medical Campus in Aurora. It is governed by the elected, nine-member Board of Regents of the University of Colorado.

University of Colorado Boulder

The University of Colorado Boulder (commonly referred to as CU, CU Boulder, or Colorado) is a public research university located in Boulder, Colorado, United States. It is the flagship university of the University of Colorado system and was founded five months before Colorado was admitted to the Union in 1876.

In 2015, the university comprised nine colleges and schools and offered over 150 academic programs and enrolled almost 17,000 students. Twelve Nobel Laureates, nine MacArthur Fellows, and 20 astronauts have been affiliated with CU Boulder as students, researchers, or faculty members in its history. The university received nearly $454 million in sponsored research in 2010 to fund programs like the Laboratory for Atmospheric and Space Physics, and JILA.

The Colorado Buffaloes compete in 17 varsity sports and are members of the NCAA Division I Pac-12 Conference. The Buffaloes have won 28 national championships: 20 in skiing, seven total in men's and women's cross country, and one in football. Approximately 900 students participate in 34 intercollegiate club sports annually as well.

Verizon Wireless

Cellco Partnership, doing business as Verizon Wireless, is an American telecommunications company which offers wireless products and services. It is a wholly owned subsidiary of Verizon Communications. Verizon Wireless is the largest wireless telecommunications provider in the United States.The company is headquartered in Basking Ridge, New Jersey. It was founded in 2000 as a joint venture of American telecommunications firm Bell Atlantic, which would soon become Verizon Communications, and British multinational telecommunications company Vodafone. Verizon Communications became the sole owner in 2014 after buying Vodafone's 45-percent stake in the company.It operates a national 4G LTE network covering about 98 percent of the U.S. population, which in December 2015 won or tied for top honors in each category of the RootMetrics RootScore Reports. Verizon Wireless offers mobile phone services through a variety of devices. Its LTE in Rural America Program, with 21 rural wireless carriers participating, covers 2.7 million potential users in 169 rural counties. Verizon Wireless announced in 2015 that it was developing a 5G, or fifth generation, network.

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