[1] The formation preserves fossils dating back to the Late/Upper Miocene epoch of the Neogene period.
[3] The presence of shell beds and mollusk fossils suggests the area was once under a shallow bay, with relatively uniform levels of salinity and sand porosity.
[3] The Tularcitos syncline is a significant geological feature in the southern part of the formation.
The high level of deformation, compared to the northern area, suggests that there was significant metamorphic activity, enabling the formation of laumontite.
[6] The presence of rocks of the Briones formation near the surface creates conditions conducive for the development of Chaparral as opposed to open grasslands or forest, though many different vegetation types have been documented occurring on the Briones Formation.