The Nine Sisters or the Morros are a chain of twenty-three, although typically only nine are included, volcanic mountains and hills in western San Luis Obispo County, Southern California. They run between Morro Bay and San Luis Obispo.
Nine Sisters | |
---|---|
Los Morros | |
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Highest point | |
Peak | Bishop Peak |
Elevation | 475 m (1,558 ft) |
Coordinates | 35°18′09″N 120°41′51″W / 35.3024744°N 120.6973949°W[1] |
Dimensions | |
Length | 16.6 mi (26.7 km) WNW–ESE |
Width | 3.9 mi (6.3 km) |
Geography | |
Countries | United States |
State | California |
Geology | |
Age of rock | 20–25 mya (Late Oligocene to Early Miocene) |
Type of rock | Volcanic plugs |
Geography
editThe peaks were created more than 20 million years ago during the Miocene Epoch of the Neogene Period, as volcanic plugs of magma which welled up and solidified inside softer rock which has since eroded away.[citation needed] Every plug, with the exception of just two, formed in a nearly straight line.
Two of the plugs are in Morro Bay State Park. The highest is Bishop Peak at 1,559 feet (475 m).
Peaks
editThe peaks in order from Morro Bay to San Luis Obispo, including their height, a sortable table.
Name | Height ft (m) |
---|---|
Morro Rock | 576 (176) |
Black Hill | 665 (203) |
Cerro Cabrillo | 911 (278) |
Hollister Peak | 1,404 (428) |
Cerro Romauldo | 1,306 (398) |
Chumash Peak | 1,257 (383) |
Bishop Peak | 1,559 (475) |
Cerro San Luis Obispo | 1,292 (394) |
Islay Hill | 775 (236) |
Geology
editThe Nine Sisters are a chain of volcanic plugs composed predominantly of dacite. About 20 to 25 million years ago, magma welled up underneath a layer of softer rock and solidified. The softer overlying rock has since eroded away, leaving a distinct rugged shape.[2]
Features
editThe Nine Sisters, being less accessible to human intrusions, support a wide variety of Coastal sage scrub and California oak woodlands flora, and of birds and other fauna.
Their volcanic origin makes them of significant geological interest. They are popular with photographers and rock climbers.
Panorama
editReferences
edit- ^ "Bishop Peak". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. Retrieved 2009-06-23.
- ^ "The Nine Sisters of San Luis Obispo County". Santa Lucia Chapter, Sierra Club. Archived from the original on 2017-02-14. Retrieved 2017-01-11.
- "The Nine Sisters of San Luis Obispo County". Sierra Club San Luis Obispo. Archived from the original on 2017-02-14. Retrieved 2009-06-25.
External links
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