Name: Diatomaceous Earth

Geologic Name:  Valmonte diatomite member of Monterey shale.

Reference:  Woodring, W. P., et al., Miocene stratigraphy and paleontology of
Palos Verdes Hills, California: Am. Assoc. Petroleum Geologists Bull. vol. 20,
No. 2, p. 127-131, 143-145, 1936.

Microscopic characters:  The slide consists of a brownish, almost nontransparent
mass of diatoms with a few irregular grains of quartz.