Painted Hills, vividly colored striped
hills.
The colors reflect changes in ancient soils and vegetation
during a major global cooling event 33 million years ago.
Sign read: "The red in the Painted
Hills is from
rusty iron minerals oxidized by long exposure.
The golden layers reveal a mix of oxidized magnesium
and iron, metamorphic claystone minerals.
Black ash marks are rich with manganese.
Each of the colors represents a different geologic process.
This valley is a gently contoured theater of geologic
change, with erosion from rain the latest sculptor."