Sometimes they seep from the ground and create large puddles known as tar pits or asphalt lakes.
La Brea Tar Pits in Los Angles.
Photo credit:Betsy Weber/Flickr
There are only a few known large asphalt lakes around the world.
The lake covers about 40 hectares and is reported to be 75 meters deep.
The liquid asphalt is so thick and viscous, that the surface can be walked upon.
But if you stand on the surface for too long, you will slowly sink into it.
The lake was discovered in 1595, and has been commercially mined since 1867.
An estimated 10 million tons of asphalt has been extracted from the Pitch Lake so far.
About 6 million tons of asphalt is still left.
The La Brea Pitch Lake is also a tourist attraction and brings about 20,000 visitors annually.
Sometimes people swim in the waters of the pitch lake because they believe it has therapeutic properties.
Pitch Lake in Trinidad.
Photo credit:r.lt/Flickr
Another famous asphalt lake is located in urban Los Angeles.
Its actually a group of pits called theLa Brea Tar Pits.
Dont be confused by the name.
Brea is just a Spanish word for asphalt.
Elsewhere, there isLake Bermudez, in Venezuela, which is the world’s second largest natural tar pit.
Tar pits have also been found in Iraq and in Baku, Azerbaijan.
These animals had wandered too far looking for food perhaps, and became trapped in the asphalt.
The trapped animals attracted predators who became stuck as well as.
Death came either by suffocation or hunger.
Its a terrible way to die, but a fantastic way to preserve fossils.
A surprisingly large percentage of fossils recovered from tar pits as high as 90 percentare that of predators.
Photo credit:Kimon Berlin/Flickr
Aside from animals, tar pits have also preserved prehistoric wood and vegetation.
But the most unexpected find is that of a woman, dated at approximately 10,000 years.
The skeleton was accompanied by the remains of a domestic dog.
Researchers believe the death might have been ceremonial or a sacrifice, just likesacrifices made in peat bogs.
Originally, the bones recovered from the pits were dismissed as recent deaths.
Between 1913 and 1915, the museum collected about a million bones.
Hancock later donated the pits to the county, on the condition that they be preserved and appropriately displayed.
Some of the fossil specimens are now displayed at the nearby George Alan Hancock Museum.
There is still at least one actively excavated pit in Rancho La Brea.
Photo credit:John Fladd/Flickr
Skeleton of an ice age bison recovered from La Brea tar pits.
Photo credit:Pauleon Tan/Flickr
Skeleton of a mammoth recovered from La Brea tar pits.
Photo credit:Roni/Flickr
Mining operations Pitch Lake Trinidad.
