Seaside - sediments (dune sand)

Sand dunes west of Highway 1 in Seaside, northeast of Monterey.

Young sediments (Quaternary, or less than 1.8 million years old) have mostly not had time to be transformed into rock, and the youngest sediments (Holocene, deposited since the last period of extensive glaciers and ice fields, or less than 11,500 years old) are usually found in their original environment of deposition. One such Holocene accumulation is that of dune sand (shown as Qs on the geologic map) which has been deposited northwest of Monterey.

The prevailing winds from Monterey Bay towards Salinas Valley have blown and piled sand from the coast into a large dune field that reaches to the Salinas River. The western part of the city of San Francisco is built on similar sand dunes.