What is a Tar Pit?
Tar pits are pools of gooey asphalt that are created when crude oil seeps up from deep inside the Earth through a crack (called a fissure). The less dense elements of the crude oil evaporate, leaving a deep, conical deposit of asphalt (a very sticky mess). Water pools atop the tar, attracting thirsty animals. As animals get stuck in the tar, predators are attracted to the trapped animals, and then they get stuck in the asphalt too. (The warmer the weather, the stickier the asphalt – more animals get trapped in the tar in warmer weather.) The animals’ bones, teeth, and other hard parts are well-preserved in this environment (but they turn brown as the asphalt seeps into them). For more information on the La Brea Tar Pits, click here.
