The Geomorphic Provinces of California

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The Geomorphic Provinces of California
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The Geomorphic Provinces of California

• Physiographic complexity- Scenic Diversity
• large size
• plate tectonics at work along western boundar
  Pacific and North American Plates
• In much of the state, these two plates are
  sliding past one another creating high forested
  mountains and deep valleys.
• In the North, the Pacific plate is, at least in
  part, sinking beneath the lighter crustal
  material of North America and this has created
  massive volcanoes and lava flows.

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Coast Ranges

• Folded and faulted
• Mendocino Ranges north of Golden Gate
• Diablo Range and Big Sur to the south
• 2,000 - 6,000 ft.
• San Andreas Fault Zone diagonally cuts across the
  area.

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Klamath Mountains

• Most complex in CA
• Numerous ranges, seemingly random orientation
• Many igneous, metamorphic, and sedimentary rocks
• Eastern peaks reach 5,000 - 9,000 ft.
• High rainfall - forests
• Pleistocene Glaciation
• Rivers cut V-shaped valleys Trinity and Klamath

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Southern Cascades and Modoc Plateau

• Lava, Lava, Lava
• Ash, domes, cinder cones, volcanic mtns.
• Lassen (10,457 ft) - 1914-1917
• Shasta (14,162 ft)
• Much of Modoc plateau is in rainshadow of
  Cascades and is thus arid (lt 20/yr)

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Mt. Shasta
Burney Falls
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Basin and Range

• Horst and Graben
• Death Valley (-282 ft)
• Pannamint Ranges - Telescope Peak (11.045 ft)
• Owens Valley
• Mono Lake
• Whole region in rainshadow of Sierra Nevada

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Owens Valley
Death Valley
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Sierra Nevada

• 400 mile long
• granitic batholith
• Mt. Whitney (14,495 ft)
• Steep eastern escarpment
• Faulted Block Construction
• Orographic Precip
• Barrier to people and animals
• Glaciation

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Great Central Valley

• San Joaquin Valley and River in south
• Sacramento Valley and River in north
• Downfolded construction
• Very thick layers of sediment - good soils
• San Francisco Bay Delta
• Seasonal flooding before Europeans
• Sutter Buttes (2,200) - volcanic

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Mojave Desert

• High Desert (4,000 - 7,000 ft)
• Highest in northeast corner
• Bounded by Garlock and San Andreas faults
• Rocks of all types exposed
• Snow in Winter
• Joshua Trees

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Colorado Desert

• Low Desert (-234 - 1,000 ft)
• Sunken fault block
• Coachella Valley in north - date palms
• Imperial Valley in south - vegetables
• San Andreas fault is widening the area
• Colorado River Drains into it.

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Transverse Ranges

• Santa Ynez, Santa Monica, San Gabriel, and San
  Bernadino Mtns.
• Trend East-West, perpendicular to other CA mtns.
• Mt. San Antonio Old Baldy in Gabriels (10,064
  ft)
• San Gorgornio in San Bernadinos (11,499 ft) is
  highest in SoCal.
• Precip low (10-40) and seasonal

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Transverse Ranges

• Santa Ynez, Santa Monica, San Gabriel, and San
  Bernadino Mtns.
• Trend East-West, perpendicular to other CA mtns.
• Mt. San Antonio Old Baldy in Gabriels (10,064
  ft)
• San Gorgornio in San Bernadinos (11,499 ft) is
  highest in SoCal.
• Precip low (10-40) and seasonal

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Santa Ynez Mountains
Mt. Wilson Observatory
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Los Angeles Basin and Penninsular Ranges

• Granitic steep eastern side
• LA basins deep alluvial fill
• Mt. San Jacinto (10,804)
• Cuyamaca and Palomar Mtns surpass 6,000 in San
  Diego
• Marine terraces in San Diego
• Penninsular Ranges extend to S. Baja.

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