Geologic Processes of Evolution
On type of Organic Trap is
tar, or natural asphalt. Tar is a residue from oil that has seeped to
the earth's surface from deposits in the rock below. When an asphalt pit
is covered by water, thirsty animals that come to the pit to drink may
become trapped in the sticky substance and be preserved. One well-known
example of such an area is the La Brea Tar Pits of the Pleistocene Epoch
(1.6 million to 10,000 years before present) in Los Angeles, California.