The Topanga Canyon Formation () is a Miocene epoch geologic formation in the Santa Monica Mountains, Simi Hills, Santa Ana Mountains and San Joaquin Hills, in Los Angeles County, Ventura County, and Orange County, southern California.USGS.gov: "Preliminary Geologic Map of the Simi 7.5' Quadrangle, Southern California, A Digital Database"; Open-File Report 97-259; compiled by R.F. Yerkes and R.H. Campbell; 1997. It is primarily composed of hard sandstone with some inter-bedded siltstone.
Fossils
It preserves fossils dating back to the Miocene epoch of the Neogene period, during the Cenozoic Era.
See also
List of fossiliferous stratigraphic units in California Paleontology in California
References