Fossil Wood from the Middle Miocene Conejo Volcanics, Santa Monica Mountains, California

Evidence that the upper Conejo Volcanics erupted subaerially is con- firmed by the discovery of fossil wood preserved in a —13.5 Ma tuff breccia exposed on the northern flank of the Santa Monica Mountains, California. This middle Miocene wood represents a low montane geoflora of hardwoods and co- nifers that lived at elevations greater than 1,300 m. Ponderosa Pine, Douglas Fir, Incense Cedar, and specimens from the dicotyledonous families Fagaceae (ever- green and live oaks), Rosaceae (mountain mahogany), and Rhamnaceae (mountain lilac) have been identified by thin section analysis. Preservation of this wood varies from amorphous clayey limb casts to splintered surfaces and detailed cell features. This is the first record of fossil trees in a tuff breccia from the Los Angeles basin region