The primary objectives at this site were to sample a high-resolution upper Miocene to Holocene sediment section from the central California Margin to study evolution of the California Current, as well as the history of upwelling and productivity. The site also provides a dipstick to sample midwaters during the time in which the Northern Hemisphere ice sheets were formed. Organic carbon contents and terrestrial organic matter input should be moderately high.
Sediments vary from siliciclastic to interbedded mixtures of biogenic and siliciclastic components.
Siliciclastic clays are found throughout the cored interval, but are predominant in the upper part. The middle part is dominated by diatom clay and diatom clay mixed sediment with frequent interbedding of clayey nannofossil ooze, whereas the lower part is dominated by interbeds of nannofossil clay and clayey nannofossil chalk. Diatomaceous layers tend to correspond to darker and less bioturbated intervals compared to nannofossil-rich layers. Vitric volcanic ash layers are rare except in the lowermost part of the sequence. The sediments are divided into two lithologic units.