Lithology and Stratigraphy
This subsection contains Quaternary nonmarine sediments.
This subsection is on gently sloping to moderately steep hills. The subsection elevation range is from less than 10 to 268 feet. Fluvial erosion is the main geomorphic process.
The soils are mostly Entic and Typic Chromoxererts and Calcixerollic Xerochrepts. They are well drained. Soil temperature regimes are thermic and soil moisture regimes are xeric.
The predominant natural plant communities are Needlegrass grasslands.
Characteristic series by lifeform include:
- Grasslands: California annual grassland series, Purple needlegrass series.
The mean annual precipitation is about 16 to 20 inches. It is practically all rain. Mean annual temperature is about 58° to 62° F. The mean freeze-free period is about 250 to 275 days.
There are no large streams in this subsection. The drainage pattern is radial. Most of the streams are dry during the summer. There are no lakes.