The La Brea Tar Pits in Los Angeles

Along Wilshire Boulevard, one of the busiest streets in Los Angeles, lies the famous La Brea Tar Pits. For tens of thousands of years tar and asphalt has collected in pools in this area. The tar is often covered by water and even leaves and dust. This makes the pits perfect traps for animals. As they come to drink they get trapped in the tar and die.

As they sink through the tar the bones of the animals absorb asphalt that helps preserve the bones in near perfect condition. The tar pits have yielded an amazing number of fossils and have played an important part in the understanding of the Los Angeles area in prehistoric times. The oldest materials recovered from the tar pits are 38 000 years old.

The first record of the Tar Pits is from 1769 when they were discovered and described by a group of Spanish explorers. They reported seeing geysers of tar and named them 'Los Volcanos De Brea', the tar volcanoes. The explorers also noted that the tar deposits were plentiful and would be a good resource for caulking ships. Over the years, tar and asphalt has been collected from the pits for different uses. The asphalt from the pits was used for a long time to pave roads in the area.

The tar pits are formed by crude oil seeping up through the ground from the Salt Lake Oil Field. As the oil biodegrades it slowly turns into asphalt that collect in pools all over the area. The Park surrounding the Tar Pits see new small pools appearing all the time. The tar in the pits seem to boil as there are constantly bubbles forming. This is caused by the bacteria that live of the petroleum in the oil. The bacteria releases methane gas that form the bubbles in the asphalt. Asphalt and methane also collects under buildings in the area. These deposits have to be removed periodically to prevent damage to the foundations.

The gas buildup also has delayed the extension of one of the Los Angeles subway lines. After a tunneling accident where a methane deposit exploded during construction a ban was placed on tunneling in the area. With new and better technology available the ban has since been lifted and construction on a subway line along Wilshire Boulevard is planned. This construction will uncover many new tar pits.

While the large skeletons of mammals are the most famous discoveries, the tar pits traps many other things. Scientists recover very small fossils of plants or insects, even plant pollen and dust, that help paint a picture of conditions in the Los Angeles basin during the ice age.

The George C. Page museum is built right next to the tar pits on Wilshire Boulevard. Visitors to the park can walk among the tar pits and see life sized models of some of the famous prehistoric animals that have been recovered from the pits. The grounds are full of active tar pits and new ones are formed constantly. One of the pits in the park is still being excavated. If you visit the tar pits in the summer you can watch as Paleontologists and students work in Pit 91.

Inside the museum building is an impressive collection of fossils. Large mammal skeletons are on display including saber-tooth tigers, bears, sloths and a near perfectly preserved mammoth. The museum also tells the story of how the Tar Pits have been excavated and includes a laboratory where scientists analyze findings from the pits. One wall of the laboratory is a long window facing into the exhibit area giving visitors a very fascinating view of the work done on the fossils.

The Tar Pits in La Brea are some of the most fossil rich deposits in the world and myriads of specimens and species have been discovered in the tar deposits. Even an 11 000 year old skeleton of a human has been found.