What Kind of Tool Does the Researcher in the La Brea Video Use to Remove Soft Matrix From the Bone?

Paleontological research site in Los Angeles

For the tar pit in La Brea, Trinidad and Tobago, see Pitch Lake.

La Brea Tar Pits and Museum
Gas bubble slowly emerging at La Brea Tar Pits (2004)
Location in Los Angeles
Location	Hancock Park, Los Angeles, United states of america
Coordinates	34°03′46″N 118°21′22″Due west  /  34.0628°N 118.356°Due west  / 34.0628; -118.356 Coordinates: 34°03′46″N 118°21′22″Westward  /  34.0628°Due north 118.356°Due west  / 34.0628; -118.356
Official website
California Historical Landmark
Official name	Hancock Park La Brea[ane]
Reference no.	170
U.S. National Natural Landmark
Designated	1964

Illustration of several species getting mired in the tar pits

La Brea Tar Pits and Museum is an active paleontological research site in urban Los Angeles. Hancock Park was formed effectually a group of tar pits where natural asphalt (also called asphaltum, bitumen, pitch, or tar; brea in Spanish) has seeped up from the ground for tens of thousands of years. Over many centuries, the tar preserved the bones of trapped animals. The George C. Page Museum is dedicated to researching the tar pits and displaying specimens from the animals that died at that place. La Brea Tar Pits is a registered National Natural Landmark.

Formation [edit]

Tar pits are composed of heavy oil fractions called gilsonite, which seeps from the World equally oil. Crude oil seeps upwards along the sixth Street Fault from the Common salt Lake Oil Field, which underlies much of the Fairfax District northward of Hancock Park.^[2] The oil reaches the surface and forms pools, condign asphalt as the lighter fractions of the petroleum biodegrade or evaporate. The asphalt so unremarkably hardens into chubby mounds. The pools and mounds tin exist seen in several areas of the park.

The lake pit was used as an cobblestone mine. Explorers excavated more than 100 sites between 1913 and 1915 in search of large mammal bones. These excavations have gradually been filled in by an accumulation of asphaltum, dust, leaves, and water.

This seepage has been happening for tens of thousands of years, during which the cobblestone sometimes formed a eolith thick enough to trap animals. The eolith would get covered over with h2o, grit, or leaves. Animals would wander in, become trapped, and die. Predators would enter to eat the trapped animals and would too go stuck. As the bones of a dead animal sink, the cobblestone soaks into them, turning them dark-chocolate-brown or black in color. Lighter fractions of petroleum evaporate from the cobblestone, leaving a more than solid substance, which so encases the bones. Dramatic fossils of large mammals have been extricated from the tar, but the cobblestone also preserves microfossils: wood and constitute remnants, rodent bones, insects, mollusks, dust, seeds, leaves, and fifty-fifty pollen grains. Examples of some of these are on display in the George C. Page Museum. Radiometric dating of preserved wood and bones has given an age of 38,000 years for the oldest known fabric from the La Brea seeps. The pits yet ensnare organisms today, so near of the pits are fenced to protect humans and animals.

History [edit]

The Tar Pits in 1910. Oil derricks can be seen in the groundwork.

The Native American Chumash and Tongva people living in the area built boats unlike any others in Northward America prior to contact by settlers. Pulling fallen Northern California redwood trunks and pieces of driftwood from the Santa Barbara Channel, their ancestors learned to seal the cracks between the boards of the large wooden plank canoes past using the natural resource of tar. This innovative form of transportation allowed access upwardly and down the coastline and to the Channel Islands. The Portolá trek, a group of Spanish explorers led by Gaspar de Portolá, made the first written tape of the tar pits in 1769. Begetter Juan Crespí wrote,

While crossing the basin, the scouts reported having seen some geysers of tar issuing from the ground like springs; it boils upwards molten, and the water runs to one side and the tar to the other. The scouts reported that they had come across many of these springs and had seen large swamps of them, enough, they said, to caulk many vessels. We were not so lucky ourselves every bit to see these tar geysers, much though nosotros wished it; equally it was some distance out of the way we were to take, the Governor [Portolá] did not want the states to go by them. Nosotros christened them Los Volcanes de Brea [the Tar Volcanoes].^[3]

Harrison Rogers, who accompanied Jedediah Smith on his 1826 expedition to California, was shown a slice of the solidified cobblestone while at Mission San Gabriel, and noted in his journal, "The Citizens of the Country brand corking use of it to pitch the roofs of their houses".^[4] The La Brea Tar Pits and Hancock Park are situated within what was one time the Mexican land grant of Rancho La Brea, now office of urban Los Angeles in the Miracle Mile district. For some years, tar-covered basic were plant on the Rancho La Brea property, simply were non initially recognized as fossils because the ranch had lost various animals–including horses, cattle, dogs, and fifty-fifty camels–whose bones closely resemble several of the fossil species. The original Rancho La Brea state grant stipulated that the tar pits be open to the public for the use of the local Pueblo. Initially, they mistook the bones in the pits for the remains of pronghorn (Antilocapra americana) or cattle that had become mired.

Early earthworks (c.  1913 – c. 1915)

in the 1880'due south the state was endemic by a Countess of Dundonald and in 1886, the first excavation for state pitch in the village of La brea began by messrs turnbull, stewart & co.^[v]

Union Oil geologist W. Westward. Orcutt is credited, in 1901, with first recognizing that fossilized prehistoric animal basic were preserved in pools of asphalt on the Hancock Ranch. In celebration of Orcutt's initial discovery, paleontologists named the La Brea coyote (Canis latrans orcutti) in his honor.^[vi]

Every bit a result of a design competition in 2019, the Natural History Museum of Los Angeles County chose Weiss/Manfredi over Dorte Mandrup and Diller Scofidio + Renfro to redesign the park, including by adding a 3,281-pes-long pedestrian walkway framing Lake Pitt.^[7]

Scientific resource [edit]

Gimmicky excavations of the bones started in 1913–1915. In the 1940s and 1950s, public excitement was generated by the training of previously recovered large mammal bones.^[8] A subsequent study demonstrated the fossil vertebrate textile was well preserved, with little evidence of bacterial degradation of bone protein.^[9] They are believed to be some x–twenty,000 years old, dating from the last glacial period.^[10]

Leaner [edit]

Methyl hydride gas escapes from the tar pits, causing bubbling that make the asphalt appear to boil. Cobblestone and methyl hydride appear under surrounding buildings and require special operations for removal to prevent the weakening of edifice foundations. In 2007, researchers from UC Riverside discovered that the bubbles were caused by hardy forms of leaner embedded in the natural asphalt. Afterwards consuming petroleum, the bacteria release marsh gas. Effectually 200 to 300 species of bacteria were newly discovered here.^[11]

George C. Page Museum [edit]

The La Brea Tar Pits Museum in Hancock Park

The George C. Folio Museum of La Brea Discoveries, role of the Natural History Museum of Los Angeles Canton, was built next to the tar pits in Hancock Park on Wilshire Boulevard. Construction began in 1975, and the museum opened to the public in 1977.^[12]

Withal, the history of the fossil museum began in 1913, when George Allan Hancock, the owner of Rancho La Brea, granted the Natural History Museum of Los Angeles County exclusive excavation rights at the Tar Pits for two years. In those ii years, the museum was able to extract 750,000 specimens at 96 sites, guaranteeing that a large collection of fossils would remain consolidated and bachelor to the community.^[13] And so in 1924, Hancock donated 23 acres to LA County with the stipulation that the county provide for the preservation of the park and the exhibition of fossils found there.^[13]

The museum tells the story of the tar pits and presents specimens excavated from them. Visitors can walk around the park and see the tar pits. On the grounds of the park are life-sized models of prehistoric animals in or virtually the tar pits. Of more 100 pits, but Pit 91 is withal regularly excavated by researchers and can be seen at the Pit 91 viewing station. In addition to Pit 91, the one other ongoing excavation is called "Project 23". Paleontologists supervise and straight the work of volunteers at both sites.^[14]

Earthworks of "Projection 23" and newly uncovered pits [edit]

2011 VOA report about the new discoveries in the pits

On February eighteen, 2009, George C. Page Museum announced the 2006 discovery of 16 fossil deposits that had been removed from the basis during the construction of an underground parking garage for the Los Angeles County Museum of Fine art side by side to the tar pits.^[15] Amidst the finds are remains of a saber-toothed cat, dire wolves, bison, horses, a giant ground sloth, turtles, snails, clams, millipedes, fish, gophers, and an American lion.^{[15] [sixteen]} Also discovered is a nearly intact mammoth skeleton, nicknamed Zed; the but pieces missing are a rear leg, a vertebra, and the top of its skull, which was sheared off by construction equipment in grooming to build the parking structure.^{[16] [17] [18]}

Lab technician working on recent specimen ZED (2021)

Lab technician doing a 3-D scan of a fossil (2021)

These fossils were packaged in boxes at the construction site and moved to a compound behind Pit 91, on Page Museum property, so that construction could proceed. Twenty-three large accumulations of tar and specimens were taken to the Page Museum. These deposits are worked on nether the name "Project 23". Equally work for the public transit D Line is extended, museum researchers know more tar pits will be uncovered, for example most the intersection of Wilshire and Curson.^[15] In an exploratory subway dig in 2014 on the Phenomenon Mile, prehistoric objects unearthed included geoducks, sand dollars, and a x-human foot limb from a pine tree, of a type now found in Central California's woodlands.^[xix]

Flora and fauna [edit]

Among the prehistoric species associated with the La Brea Tar Pits are Pleistocene mammoths, dire wolves, short-faced bears, American lions, footing sloths, and, the state fossil of California, the saber-toothed true cat (Smilodon fatalis).

The park is known for producing myriad mammal fossils dating from the last glacial period. While mammal fossils generate significant interest, other fossils, including fossilized insects and plants, and fifty-fifty pollen grains, are also valued. These fossils aid define a picture of what is thought to have been a cooler, moister climate in the Los Angeles basin during the glacial age. Amid these fossils are microfossils, which are retrieved from a matrix of asphalt and sandy clay by washing with a solvent to remove the petroleum, then picking through the remains nether a high-powered lens.

Tar and wild flower run within La Brea campus (2014)

Tar pits effectually the world are unusual in accumulating more predators than prey. The reason for this is unknown, but one theory is that a big prey animal would dice or go stuck in a tar pit, alluring predators across long distances. This predator trap would take hold of predators along with their prey. Another theory is that dire wolves and their prey were trapped during a hunt. Since modernistic wolves chase in packs, each casualty animal could take several wolves with it. The aforementioned may be true of saber-toothed cats known from the area. The most common animals from this surface area included dire wolves, saber-toothed cats, coyotes, ancient bison, and Jefferson's ground sloth.^{[xx] [21] [22] [23]}

Saber-toothed cat display

Human presence [edit]

Only i man has been found, a fractional skeleton of the La Brea Adult female^[24] dated to effectually 10,000 calendar years (about 9,000 radiocarbon years) BP,^[25] who was 17 to 25 years old at death^[26] and found associated with remains of a domestic dog, so was interpreted to have been ceremonially interred.^[27] In 2016, however, the dog was determined to exist much younger in engagement.^[28]

John C. Merriam of the University of California led much of the original work in this area early in the 1900s.

Also, some even older fossils showed possible tool marks, indicating humans active in the surface area at the time. Saber-toothed cat bones from La Brea showing signs of 'bogus' cut marks at oblique angles to the long axis of each bone were radiocarbon dated to xv,200 ± 800 B.P. (uncalibrated).^[29]

If these cuts are in fact tool marks resultant from butchering activities, then this cloth would provide the earliest solid show for human association with the Los Angeles Basin. Yet it is too possible that there was some balance contamination of the material equally a result of saturation by asphaltum, influencing the radiocarbon dates.^[30]

See too [edit]

• Binagadi asphalt lake
• Carpinteria Tar Pits
• Lagerstätten
• Lake Bermudez
• List of fossil sites
• Los Angeles Canton Museum of Art
• McKittrick Tar Pits
• Pitch Lake

References [edit]

1. ^ "Hancock Park". Role of Historic Preservation, California State Parks. Retrieved October 7, 2012.
2. ^ Khilyuk, Leonid F.; Chilingar, George V. (2000). Gas migration: events preceding earthquakes. Gulf Professional Publishing. p. 389. ISBN0-88415-430-0.
3. ^ Kielbasa, John R. (1998). "Rancho La Brea". Historic Adobes of Los Angeles County. Pittsburg: Dorrance Publishing Co. ISBN0-8059-4172-X. .
4. ^ Smith, J. S., & Brooks, 1000. R. (1977). The Southwest trek of Jedediah S. Smith: His personal business relationship of the journeying to California, 1826–1827. Glendale, Calif: A. H. Clark, p. 239. ISBN 0-8706-2123-8
5. ^ Mineral Resources of the United States. (1894). United States: U.S. Government Press Function.
6. ^ "Horticulture Centers and Gardens | City of Los Angeles Department of Recreation and Parks". www.laparks.org . Retrieved June 20, 2020.
7. ^ Shane Reiner-Roth (Dec 12, 2019), WEISS/MANFREDI win contest to master plan the La Brea Tar PitsThe Architect'south Newspaper.
8. ^ "Animal Bones 50,000 Years Old Found In Tar". Los Angeles Times. Los Angeles. June 17, 1946. Retrieved January 27, 2010.
9. ^ McMenamin, M.A.Due south.; et al. (1982). "Amino acid geochemistry of fossil bones from the Rancho La Brea Asphalt Deposit, California". Quaternary Enquiry. 18 (two): 174–83. Bibcode:1982QuRes..18..174M. doi:10.1016/0033-5894(82)90068-0.
10. ^ Ley, Willy (December 1963). "The Names of the Constellations". For Your Information. Galaxy Science Fiction. pp. 90–99.
11. ^ Jia-Rui Chong, "Researchers learn why tar pits are bubbly", Los Angeles Times, May 14, 2007.
12. ^ Page Museum. "About the museum". Page Museum web site. The Natural History Museum of Los Angeles County Foundation. Retrieved Jan 25, 2016.
13. ^ ^{a b} "La Brea Tar Pits History | La Brea Tar Pits". tarpits.org . Retrieved June xx, 2020.
14. ^ Page Museum. "Page Museum—La Brea Tar Pits". Page Museum web site. The Natural History Museum of Los Angeles County Foundation. Retrieved December xv, 2006.
15. ^ ^{a b c} "Cache Of Ice Historic period Fossils Plant About Tar Pits". Los Angeles: KCBS-Tv. Associated Press. Feb 18, 2009. Archived from the original on February 20, 2009. Retrieved February 18, 2009.
16. ^ ^{a b} Thomas H. Maugh II (February 18, 2009). "Major cache of fossils unearthed in L.A." Los Angeles Times. Los Angeles. Retrieved February 18, 2009.
17. ^ "Workers Unearth Mammoth Discovery near La Brea Tar Pits". Los Angeles: KTLA. February 18, 2009. Retrieved February 18, 2009.
18. ^ "About intact mammoth found at L.A. construction site". USA Today. Feb 18, 2009. Retrieved September 1, 2010.
19. ^ Malkin, Bonnie (March 7, 2014). "Prehistoric objects unearthed in LA subway dig". The Telegraph (U.k.). AP. Archived from the original on January 12, 2022. Retrieved March 18, 2014.
20. ^ "Mammal Collections". La Brea Tar Pits & Museum. Natural History Museums of Los Angeles County. Retrieved May 9, 2021.
21. ^ Ojibwa (February 21, 2018). "Paleontology 101: Bison and Camels at the La Brea Tar Pits". Daily Kos. Kos Media, LLC. Retrieved May 9, 2021.
22. ^ Ojibwa (Dec xiii, 2017). "Paleontology 101: The Dire Wolf". Daily Kos. Kos Media, LLC. Retrieved May 9, 2021.
23. ^ Udurawane, Vasika; Lacerda, Julio (2016). "Trapped in tar: The Ice Historic period animals of Rancho La Brea". Earth Archives . Retrieved May nine, 2021.
24. ^ J.C. Merriam (1914) Preliminary study on the discovery of man remains in an asphalt eolith at Rancho La Brea, Science 40: 197–203
25. ^ F.R. O'Keefe, E.Five. Fet, and J.M. Harris (2009) Compilation, scale, and synthesis of faunal and floral radiocarbon dates, Rancho La Brea, California, Contributions in Scientific discipline 518: 1–16
26. ^ G.East. Kennedy (1989) A note on the ontogenetic historic period of the Rancho La Brea hominid, Los Angeles, California, Bulletin, Southern California Academy of Sciences 88(iii): 123–26
27. ^ R.L. Reynolds (1985) Domestic canis familiaris associated with human remains at Rancho La Brea, Bulletin, Southern California University of Sciences 84(2): 76–85
28. ^ Fuller, Benjamin T.; Southon, John R.; Fahrni, Simon 1000.; Harris, John M.; Farrell, Aisling B.; Takeuchi, Gary T.; Nehlich, Olaf; Richards, Michael P.; Guiry, Eric J.; Taylor, R. E. (2016). "Tar Trap: No Prove of Domestic Dog Burial with "La Brea Adult female"". PaleoAmerica. 2: 56–59. doi:10.1179/2055557115Y.0000000011. S2CID 130862425.
29. ^ Moratto, Chiliad. 1984. California Archaeology. Florida: Academic Printing, p.54
30. ^ Technical report for power institute construction. CULTURAL RESOURCES. California Energy Commission, Sacramento, California, December 2000

External links [edit]

• Page Museum – La Brea Tar Pits
• UCMP Berkeley website: describes the geology and paleontology of the asphalt seeps.
• Gocalifornia.com: La Brea Tar Pits – company guide.
• Palaeo.uk: "Setting the La Brea site in context."
• NHM.org: Pit 91 excavations

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Source: https://en.wikipedia.org/wiki/La_Brea_Tar_Pits

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