Round Top is an

extinct volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are ...

in the

Berkeley Hills The Berkeley Hills are a range of the Pacific Coast Ranges that overlook the northeast side of the valley that encompasses San Francisco Bay. They were previously called the "Contra Costa Range/Hills" (from the original Spanish ''Sierra de la C ...

, just east of

Oakland, California Oakland is the largest city and the county seat of Alameda County, California, United States. A major West Coast of the United States, West Coast port, Oakland is the largest city in the East Bay region of the San Francisco Bay Area, the third ...

. The peak lies entirely within the bounds of

Contra Costa County ) of the San Francisco Bay , subdivision_type = Country , subdivision_name = United States , subdivision_type1 = State , subdivision_name1 = California , subdivision_type2 ...

. In 1936, the area surrounding the peak was established as Round Top Regional Park, one of the first three parks of the

East Bay Regional Parks District The East Bay Regional Park District (EBRPD) is a special district operating in Alameda County and Contra Costa County, California, within the East Bay area of the San Francisco Bay Area. It maintains and operates a system of regional parks which ...

. The park was renamed

Sibley Volcanic Regional Preserve Robert Sibley Volcanic Regional Preserve is located in the Oakland Hills of the East Bay region of the San Francisco Bay Area, California. The park is part of the East Bay Regional Parks District (EBRPD), covers , and lies east of Oakland, partly i ...

for the second president of the park district (1948 to 1958), Robert Sibley, shortly after his death in 1958. The eruptions that lead to Round Top started 10.2 Million years ago and ended more than a million years later. Two main vents of the old volcano are known, one is now under the

Lawrence Berkeley National Laboratory Lawrence Berkeley National Laboratory (LBNL), commonly referred to as the Berkeley Lab, is a United States Department of Energy National Labs, United States national laboratory that is owned by, and conducts scientific research on behalf of, t ...

, the other is Round Top. The Round Top vent has, over the years, fallen sideways.

References

External links

* * Volcanoes of California Berkeley Hills Landforms of Contra Costa County, California Mountains of the San Francisco Bay Area Extinct volcanoes East Bay Regional Park District Parks in Contra Costa County, California {{ContraCostaCountyCA-geo-stub

See also

References

External links