Project #19: Opal Cliffs
GEOMORPHIC SETTING: Sea cliff subject to active erosion and periodic retreat. The Opal Cliffs-Capitola reach is characterized by an irregular shoreline backed by cliffs ranging from 35 to 75 ft in height. The coastal cliffs throughout most of the city of Santa Cruz and neighboring Capitola are composed of erodible sediments of the Purisma Formation (siltstone and sandstone) along with the Santa Cruz Mudstone. These sedimentary rocks are often capped by 6–20 ft of unconsolidated marine and non-marine terrace deposits. The horizontal bedrock stratigraphy is easily visible in exposed or bare sections of the cliffs.
KeywordsSandstone Beach Trench Stratigraphy Mudstone
- Brabb, E. (1997). Geologic Map of Santa Cruz County. US Geological Survey, Menlo Park, CAGoogle Scholar