La Brea Tar Pits facts for kids
Quick facts for kids La Brea Tar Pits |
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Methane gas bubble emerging at La Brea Tar Pits (2004)
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 La Brea Tar Pits
Location in the Los Angeles metropolitan area
La Brea Tar Pits
Location in California
La Brea Tar Pits
Location in the United States
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| Location | Hancock Park, Los Angeles, US |
| Official name: Hancock Park La Brea | |
| Reference #: | 170 |
| Designated: | 1964 |
The La Brea Tar Pits are a famous place in Los Angeles where scientists study ancient life. This area, called Hancock Park, has many natural tar pits. For thousands of years, sticky, natural asphalt (also known as tar or pitch) has slowly oozed out of the ground here.
Over a very long time, the bones of animals that got stuck in the tar have been kept safe. The George C. Page Museum is right next to the tar pits. It helps scientists learn more about the pits and shows off the amazing fossils found there. The La Brea Tar Pits are also a special place called a National Natural Landmark.
Contents
How the Tar Pits Formed
Tar pits are made of thick, oily stuff called asphalt. This asphalt slowly leaks out of the Earth. It comes from an oil field deep underground in Los Angeles. When the oil reaches the surface, it forms pools. The lighter parts of the oil then dry up or break down, leaving behind the thick, sticky asphalt. This asphalt often hardens into small hills or mounds. You can still see these pools and mounds in the park today.
This natural process has been happening for tens of thousands of years. Sometimes, the asphalt pools became thick enough to trap animals. Water, dust, or leaves would cover the sticky surface. Animals would walk onto it, get stuck, and then die. Other animals, like predators, would come to eat the trapped animals and also get stuck themselves.
As an animal's bones sank into the tar, the asphalt would soak into them. This turned the bones dark brown or black. The asphalt then became even more solid, covering and protecting the bones.
Scientists have found amazing fossils of huge animals here. But the tar also saves tiny fossils, like pieces of wood, plants, small animal bones, insects, seeds, and even pollen. Some of these tiny fossils are on display at the George C. Page Museum. Scientists can figure out how old these fossils are. The oldest ones found at La Brea are about 38,000 years old!
History of La Brea Tar Pits
Long ago, Native American groups like the Chumash and Tongva used the tar from these pits. They used it to seal their wooden boats, called tomols. This made the boats waterproof for traveling along the coast and to nearby islands.
The first written record of the tar pits was in 1769. A group of Spanish explorers, led by Gaspar de Portolá, saw them. A priest named Father Juan Crespí wrote about "geysers of tar" bubbling from the ground. He said there was enough tar to seal many ships. They named the area Los Volcanes de Brea, which means "The Tar Volcanoes."
Later, in 1826, an explorer named Harrison Rogers saw the hardened asphalt. He wrote that local people used it to waterproof the roofs of their homes.
The land where the La Brea Tar Pits are was once part of a large Mexican ranch called Rancho La Brea. For many years, people found tar-covered bones on the ranch. But they didn't realize these were fossils at first. They thought they were just bones from ranch animals that had gotten stuck. The original land grant said that the tar pits should be open for public use.
There used to be over 100 separate tar pits. But over time, most of them were filled in with rocks or dirt. Today, about a dozen pits can still be seen at ground level.
Discovering Fossils and Excavations
In 1901, a geologist named William Warren Orcutt was the first to realize that the bones in the asphalt pools were actually ancient animal fossils. Because of his important discovery, a type of ancient coyote found there was named Canis latrans orcutti in his honor.
Serious digging for fossils began between 1913 and 1915. Scientists found that the fossil bones were very well preserved. They are mostly from animals that lived between 10,000 and 20,000 years ago, during the last Ice Age.
In 2009, the George C. Page Museum announced an exciting discovery. During construction for an underground parking garage next to the tar pits, 16 new fossil sites were found! These sites contained bones of many animals, including saber-toothed cats, dire wolves, bison, horses, giant ground sloths, and even a nearly complete mammoth skeleton nicknamed Zed. These new finds are being studied in a project called "Project 23."
As new subway lines are built in Los Angeles, scientists expect to find even more tar pits and fossils. For example, during a subway dig in 2014, they found ancient clams, sand dollars, and a 10-foot long pine tree branch.
George C. Page Museum
In 1913, George Allan Hancock, who owned the land, gave the Natural History Museum of Los Angeles County the right to dig for fossils at the Tar Pits for two years. In that short time, the museum found 750,000 fossils! This made sure that a huge collection of fossils would be kept together for everyone to see and study.
Then, in 1924, Mr. Hancock gave 23 acres of land to Los Angeles County. He said the county must protect the park and show the fossils found there.
The George C. Page Museum of La Brea Discoveries was built right next to the tar pits in Hancock Park. Construction started in 1975, and the museum opened in 1977. It's located in a busy part of Los Angeles.
The museum teaches visitors all about the tar pits and displays the amazing fossils found there. Visitors can also walk around the park and see the actual tar pits. There are even life-sized models of ancient animals stuck in or near the pits. Of the many pits, only Pit 91 is still regularly dug up by scientists. You can watch them work at the Pit 91 viewing station. "Project 23" is another ongoing excavation site. Scientists lead the work, and many volunteers help them dig and clean the fossils.
A Special Heritage Site
The La Brea Tar Pits are considered the "richest paleontological site on Earth" for land fossils from the late Ice Age. Because of this, a group called the International Union of Geological Sciences (IUGS) named it one of the top 100 geological heritage sites in the world in 2022. This means it's a very important place for understanding Earth's history and how geology has helped science grow.
Ancient Animals and Plants
Many amazing ancient animals from the Ice Age have been found at the La Brea Tar Pits. These include huge Columbian mammoths, fierce dire wolves, giant short-faced bears, powerful American lions, and slow-moving ground sloths. The official state fossil of California, the saber-toothed cat (Smilodon fatalis), is also found here.
While large mammal fossils are very exciting, scientists also find many other things. These include fossilized insects, plants, and even tiny pollen grains. These smaller fossils help scientists understand what the climate was like in Los Angeles during the Ice Age. It was much cooler and wetter back then! Scientists use special methods to clean these tiny fossils from the sticky tar and sand.
Why So Many Carnivores?
For a long time, scientists noticed that a lot of the large mammal fossils found at La Brea were carnivores (meat-eaters). This led to the idea of a "carnivore trap." The idea was that large plant-eating animals would get stuck in the tar. Then, predators and scavengers would come to eat the trapped animals and get stuck themselves.
However, newer research looking at tiny fossils shows that there were actually many different types of mammals. One paleontologist, Thomas Halliday, explained that the tar pits often trap many plant-eaters. Then, only a few carnivores get stuck when they try to scavenge on the already trapped animals.
Bacteria and Bubbles
If you visit the tar pits, you might see bubbles rising to the surface, making the tar look like it's boiling. These bubbles are actually Methane gas escaping from the tar. This gas can even appear under nearby buildings, so it needs to be removed to keep foundations safe.
In 2007, scientists discovered that these bubbles are caused by special types of bacteria living in the natural asphalt. These tiny bacteria eat the petroleum (oil) and then release methane gas. Scientists have found about 200 to 300 new kinds of bacteria living in the La Brea Tar Pits!
Signs of Early Humans
Only one human fossil has been found at the La Brea Tar Pits. It's a partial skeleton of a young woman, called La Brea Woman. She was between 17 and 25 years old when she died, about 10,000 years ago. Her remains were found with a domestic dog, which made scientists think she might have been buried on purpose. However, later studies showed the dog was much younger.
Some older animal fossils from La Brea show marks that might have been made by tools. These marks could mean that humans were in the area around 15,200 years ago. If these are truly tool marks from butchering animals, it would be the earliest proof of humans living in the Los Angeles area. But scientists are still studying this, as the tar itself might have affected the dating of the bones.
Images for kids
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Tar and wild flower run within La Brea campus (2014)
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Skeleton of a Columbian mammoth from the tar pits, displayed in the George C. Page Museum
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Models of a saber-toothed cat (Smilodon fatalis) and ground sloth on display in 2023
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Fossil crate (2021)
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Lab technician working on recent specimen ZED (2021)
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Lab technician doing a 3-D scan of a fossil (2021)
See also
In Spanish: Pozos de asfalto de La Brea para niños
- Binagadi asphalt lake
- Carpinteria Tar Pits
- Lagerstätten
- Lake Bermudez
- List of fossil sites
- Los Angeles County Museum of Art
- McKittrick Tar Pits
- Pitch Lake
