| Revision as of 06:04, 4 June 2012 editMissvain (talk | contribs)Autopatrolled, Administrators235,516 edits Added photo← Previous edit | Revision as of 23:05, 9 August 2012 edit undoRkarm (talk | contribs)1 editm →External linksNext edit → | ||
| Line 8: | Line 8: | ||
| ==External links== | ==External links== | ||
| * | * | ||
| * | |||
| {{coord missing|Contra Costa County, California}} | {{coord missing|Contra Costa County, California}} | ||
Revision as of 23:05, 9 August 2012
Robert Sibley Volcanic Regional Preserve is located in the Berkeley Hills just east of Oakland, California, USA. Though it can only be entered via Oakland, it actually lies almost entirely within Contra Costa County.
The park was one of the first three parks established by the East Bay Regional Parks District (EBRPD) in 1936. It was originally named Round Top Regional Park. Round Top (elevation 1,761 feet/537m) is an extinct volcano in the Berkeley Hills. It is home to several stone labyrinths of recent origin. The park was renamed for the second president of the EBRPD, Robert Sibley, shortly after his death.
The preserve contains a volcanic center that, about 10 million years ago, produced most of the lavas that underlie the East Bay ridges from Inspiration Point in Tilden Regional Park to Moraga; geologists refer to this local volcanism as the Moraga Volcanics. Subsequent compressive strains produced by various local faults including the Hayward Fault folded the lava-bearing rock formations, tilting the Round Top vent complex on its side. Folding, erosion, and a quarry operation exposed a cross section of the great volcano, providing an excellent means to study a Central Coast range volcano. Lava within the vent has been dated by UC Berkeley at 9.5 million years old.
External links
"Contra Costa County, California" is an invalid category parameter for Template:Coord missing.
The problem is usually caused either by a spelling mistake or by an-over-precise category.
For a full list of categories, see Category:Unclassified articles missing geocoordinate data and its subcategories.
| East Bay Regional Parks | |
|---|---|
| Parks | |
| Shorelines | |
| Preserves/open spaces | |
| Wilderness areas | |
| Recreation areas | |
| Trails | |
| Other | |
 | This Contra Costa County, California–related article is a stub. You can help Misplaced Pages by expanding it. |