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| | La Brea Tar Pits |
 | | For these are the La Brea tar pits, containing one of the richest, best preserved, and best studied assemblages of Pleistocene vertebrates, including at least 59 species of mammal and over 135 species of bird. |
 | | Tar pits form when crude oil seeps to the surface through fissures in the Earth's crust; the light fraction of the oil evaporates, leaving behind the heavy tar, or asphalt, in sticky pools. |
 | | Tar from the La Brea tar pits was used for thousands of years by local native Americans, as a glue and as waterproof caulking for baskets and canoes. |
| www.ucmp.berkeley.edu /quaternary/labrea.html (812 words) |
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