It preserves fossils dating back to the Late Miocene of the Neogene period, among them a high number of fossil representatives of modern pelagic and deep-sea fish taxa (as well as some with benthic affinities), in addition to some seabirds and cetaceans.
As suggested from this fauna, the sediments of the formation were likely deposited in a deepwater marine habitat at middle to upper bathyal depths within an abyssal fan, with geological changes along the San Andreas fault causing a rapid uplift during the latest Miocene, bringing these former deepwater sediments to the surface.
Much of the fauna is shared with the Monterey Formation, though some distinct taxa are also known:[4][5] Based on Fierstine et al (2012).
Many of these taxa were described by David Starr Jordan from specimens excavated during the construction of the Sepulveda Boulevard Tunnel through the Santa Monica Mountains.
You can help Wikipedia by expanding it.This article related to the Neogene period is a stub.