Title: Anza-Borrego Desert State Park - Wikipedia
Headings: Anza-Borrego Desert State Park
Anza-Borrego Desert State Park
Contents
Geography
Blair Valley
Visiting
Flora and fauna
Desert bighorn sheep
Climate
Geology and paleontology
Geology
Fossils
Marine period
Terrestrial period
Native Americans
Park interpretive associations
Gallery
See also
References
Specific
Further reading
External links

Content: Six million years ago, the ancestral Gulf of California filled the Salton Trough, extending northward past what would become the city of Palm Springs. These tropical waters supported a profusion of both large and small marine organisms. Through time, the sea gave way as an immense volume of sediment eroded during the formation of the Grand Canyon spilled into the Salton Trough. Little by little, the ancestral Colorado River built a massive river delta across the sea way. Fossil hardwoods from the deltaic sands and associated coastal plain deposits suggest the region received three times as much rainfall as now. The Anza-Borrego region gradually changed from a predominantly marine environment into a system of interrelated terrestrial habitats. North of the Colorado River Delta and intermittently fed by the river, a sequence of lakes and dry lakes has persisted for over three million years. At the same time, sediments eroded from the growing Santa Rosa Mountains and other Peninsular Ranges to spread east into the trough. These sediments provide an almost unbroken terrestrial fossil record, ending only a half million years ago. Here, the deposits of ancient streams and rivers trapped the remains of wildlife that inhabited a vast brushland savannah laced with riparian woodlands .