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This
subsection is a steep mountainous area south-southeast of Orick.
It is a narrow strip bounded on the east-northeast by the Grogan fault,
which is along Redwood Creek, and on the west-southwest by the Bald
Mountain fault. It has a temperate, humid climate. There is
substantial oceanic influence on climate, including summer fog.
MLRA 4b.
Lithology and Stratigraphy. This subsection is dominated by Jurassic and Cretaceous Franciscan sedimentary, minor volcanic, and metamorphic rocks, including the schist of Redwood Creek. They are intensely folded and faulted of the Eastern Belt. There are small areas of recent alluvium along Prairie and Redwood Creeks.
Geomorphology.
This is a subsection of mountains with rounded ridges, steep and moderately
steep sides, and narrow canyons. Most of the mountains are elongated
in north-northwest to northwest directions and have subequal summits with
increasing elevation toward the interior. The valleys of Prairie
and Redwood Creeks are broad enough near their mouths to contain appreciable
floodplain. The subsection elevation range is from sea-level up to
4637 feet on Mt. Andy. Mass wasting and fluvial erosion are the main
geomorphic processes.
Soils. The soils are mostly Typic Humitropepts and less extensive Orthoxic Tropohumults. The soils are leached free of carbonates and the older ones are strongly acid. The soil temperature regimes are predominantly isomesic. Soil moisture regimes are mostly udic.
Vegetation. The predominant natural plant community is Redwood series. Red alder series is common in riparian areas.
Surface Water. Runoff is rapid and many of the smaller
streams are dry by the end of the summer. Natural lakes are
absent. Brackish water lagoons are common along the coast.
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