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meditate, and examine talismans left in the center by previous visitors. In this labyrinth, she would walk her goats, stating that, "I can enter with a question, and inevitably, I will emerge with some insight. It is a powerful spot." Notwithstanding the official gate hours listed below, Friends of the
Labyrinth claims that the labyrinth has visitors 24 hours a day, 7 days a week.
338:. There are no picnic areas in the preserve; however, there are plenty of benches good for a rest, view and snack, as well as a campground. The visitor center at the Skyline Boulevard entrance is unstaffed and offers brochures for self-guided tours. It also features depictions of the region's geology.
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At least two man-made labyrinths exist within RSVRP. The first, and arguably most frequently visited, is known as the
Mazzariello Labyrinth. Constructed in 1990 and donated as a "gift to the world" by East Bay resident Helena Mazzariello, it is a favorite destination for hikers who come to pray,
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A bake zone is a region where heat from the lava of the volcano changed the color of the surrounding rocks to red. Such rocks include rhyolite tuff, lapilli agglomerate, and vesicular basalt. Rhyolite tuff are remnants of ash from a northern volcano around 4 miles (6.4 km) away. Lapilli
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There have been claims of other, earlier labyrinths hidden in the preserves, but
Friends of the Labyrinth dismisses these as urban legends, as no evidence has been found. The organization reports that analysis of high-resolution aerial photographs show no trace of such activity.
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The next marker along the Round Top Loop Trail leads to the
Volcanic Trail, which crosses to the left. At Post No. 4, the hiker can see a smaller, heart-shaped labyrinth. It is not nearly as elaborate as the Mazzariello Labyrinth, and apparently not as heavily used.
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folded the lava-bearing rock formations, tilting the Round Top vent complex on its side. The results of such compressive strains of local faults has altered the volcano's original landscape, and Round Top now tilts towards the east. Such local faults, notably
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The Stone
Property is a restricted region of the park. The area consists of pure basalt around 100 feet (30 m) wide, as well as "autobrecciating basaltic flow" which occurs when lava continues to flow under a cooled surface.
285:. From the Orinda Formation rocks include "river gravel, sandstone, and mudstone." The river gravel are red in color. The sandstones are around 65 million years old. From the Claremont Formation, rocks include marine rocks.
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There are several trails in the preserve. Most are restricted to hiking and horseback use and only a few are available for multi-purpose use. Round Top Road is paved from the visitor center to the top of
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Helena
Mazzariello is a sculptor, psychic, and shamanic practitioner who lived in Oakland's Montclair District. The labyrinth she created is known as The Sibley Labyrinth, or "Mazzariello's labyrinth"
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studied the Sibley
Regional Preserve extensively, dating the volcano to be 10.2 million years old. Since 10.2 million years ago, the Pacific tectonic plate has slowly pushed the volcano north.
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193:(elevation 1,761 feet ) is named for an extinct volcano in the Oakland Hills which started to erupt 10.2 Million years ago. It is home to at least two stone
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volcanic center that, about ten million years ago, produced most of the lavas that underlie the East Bay ridges from
Inspiration Point in
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of Round Top are of the color "light brownish or rusty gray" and the interior of the basalt is of the color "gun steel blue."
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is not the volcano. The ancient volcano has eroded away. It has also tilted on its side, so it doesn't look like a volcano. (
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Folding, erosion, and a quarry operation exposed a cross section of the volcano, providing an excellent means to study a
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161:. The park is part of the East Bay Regional Parks District (EBRPD), covers 928 acres (3.76 km), and lies east of
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used the region as a quarry, leaving the volcanic region open and exposed. Lava within the vent has been dated by
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agglomerate are remnants of volcanic cinders. Vesicular basalt are remnants of gas bubbles from cooling lava.
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173:. It can be entered from Oakland via Skyline Boulevard, or from Contra Costa County via Old Tunnel Road.
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USGS.gov: "Upper
Cretaceous and Lower Tertiary Rocks Berkeley and San Leandro Hills, California"
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is a short trail segment that descends to a couple of ponds on the north side of the preserve.
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American vetch is native to
California and can be found at Sibley Volcanic Regional Preserve.
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Geology.about.com: "California Transect - Stop 30, Orinda Formation and Moraga Volcanics"
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Jones, Nicole. "Sibley Regional Preserve: A walk on Oakland’s wild and volcanic side."
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https://www.kqed.org/news/11876393/wait-there-was-a-volcano-in-the-east-bay-hills
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of recent origin. The park was renamed after the second president of the EBRPD,
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229:. Subsequent compressive strains produced by various local faults such as the
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connects the middle of Volcanic Trail to a point lower down on Quarry Road.
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goes from the Sibley visitor center to the peak of Round Top. CLOSED
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The park was one of the first three parks established by the
654:"Berkeley Lab Geologist Studies the Ground Beneath His Feet"
242:, have also caused the volcano to form a trough that is the
201:, shortly after his death. U.C. Berkeley Professor Emeritus
716:"Friends of the Labyrinth" website. Accessed March 8, 2019.
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The park is open year-round. The park and gate hours are:
593:, by J. E. Case, GEOLOGICAL SURVEY BULLETIN 1251-J, 1968.
682:"Mazzariello's Maze." Friends of the Labyrinth. Undated
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Oakland Geology Blog: "Grizzly Peak and Moraga basalt"
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The other two original parks were Tilden and Temescal.
225:. Geologists refer to this local volcanism as the
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629:"Exploring Sibley Volcanic Regional Preserve"
61:Alameda and Contra Costa Counties, California
27:Nature preserve in the San Francisco Bay Area
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1217:Geology of Contra Costa County, California
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277:The region has remnants of rocks from the
185:(EBRPD) in 1936. It was originally named
1207:Parks in Contra Costa County, California
723:Robert Sibley Volcanic Regional Preserve
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433:There is no parking fee and no dog fee.
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143:Robert Sibley Volcanic Regional Preserve
33:Robert Sibley Volcanic Regional Preserve
1171:Breuner Marsh (now Dotson Family Marsh)
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1212:Geology of Alameda County, California
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48:at Sibley Volcanic Regional Preserve
1232:Parks in the San Francisco Bay Area
1202:Parks in Alameda County, California
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18:Sibley Volcanic Regional Preserve
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183:East Bay Regional Parks District
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1197:East Bay Regional Park District
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348:East Bay Skyline Regional Trail
261:) The construction corporation
135:East Bay Regional Park District
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426:November - February 7AM - 6PM
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1:
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429:March - October 7AM - 10PM
356:Anthony Chabot Regional Park
352:Wildcat Canyon Regional Park
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453:Pliocene California geology
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10:
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1146:Crown Memorial State Beach
652:Chao, Julie (2010-07-06).
269:at 9.5 million years old.
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1161:Little Hills Picnic Ranch
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370:circles Round Top's peak.
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565:"Voice of the Volcano -"
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263:Kaiser Sand & Gravel
213:The preserve contains a
118:928 acres (3.76 km)
1227:Volcanism of California
1166:Point Molate Beach Park
1136:Ardenwood Historic Farm
761:East Bay Regional Parks
721:EBparks.org: Official
703:Accessed July 13, 2018.
458:Volcanism of California
251:California Coast Ranges
187:Round Top Regional Park
921:Martin Luther King Jr.
684:Accessed July 13, 2018
397:
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253:volcano. The mountain
155:San Francisco Bay Area
99:37.85495°N 122.20326°W
955:Preserves/open spaces
395:
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244:Siesta/Gateway Valley
1151:Eastshore State Park
368:Round Top Loop Trail
219:Tilden Regional Park
104:37.85495; -122.20326
1222:Pliocene California
967:Black Diamond Mines
288:The surface of the
283:Claremont Formation
171:Contra Costa County
95: /
70:Oakland, California
449:formation in park.
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309:The Stone Property
145:is located in the
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825:Dry Creek Pioneer
445:— Pliocene epoch
418:Visiting the park
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66:Nearest city
16:(Redirected from
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1067:Recreation areas
1041:Wilderness areas
1002:Morgan Territory
977:Claremont Canyon
911:Carquinez Strait
840:Pleasanton Ridge
815:Diablo Foothills
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701:. July 22, 2011.
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523:"EBRPD - Sibley"
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443:Moraga Formation
279:Orinda Formation
227:Moraga Volcanics
131:Operated by
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215:Pliocene epoch
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203:Garniss Curtis
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167:Alameda County
153:region of the
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292:found on the
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231:Hayward Fault
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199:Robert Sibley
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147:Oakland Hills
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1089:Quarry Lakes
1012:Round Valley
1006:
997:Mission Peak
992:Leona Canyon
982:Five Canyons
962:Bishop Ranch
941:Point Pinole
936:Point Isabel
820:Dublin Hills
800:Coyote Hills
722:
698:
661:. Retrieved
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636:. Retrieved
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572:. Retrieved
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530:. Retrieved
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380:Quarry Trail
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326:A view from
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165:, partly in
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1074:Cull Canyon
1048:Las Trampas
1027:Vasco Caves
987:Huckleberry
972:Brushy Peak
926:Miller/Knox
835:Lake Chabot
795:Contra Loma
790:Castle Rock
658:News Center
267:UC Berkeley
102: /
90:122°12′12″W
77:Coordinates
1186:Categories
1120:Iron Horse
1079:Don Castro
931:Oyster Bay
889:Shorelines
850:Ridgelands
663:2021-05-11
638:2022-10-22
574:2022-10-22
569:Bay Nature
532:2021-05-11
493:References
401:Labyrinths
386:Pond Trail
318:Activities
195:labyrinths
159:California
87:37°51′18″N
44:View from
1032:Waterbird
901:Big Break
810:Del Valle
336:Round Top
328:Round Top
300:Bake Zone
255:Round Top
191:Round Top
46:Round Top
865:Temescal
437:See also
281:and the
151:East Bay
58:Location
1094:Roberts
916:Hayward
845:Redwood
785:Briones
725:website
236:Hayward
209:Geology
177:History
163:Oakland
149:of the
123:Created
1108:Trails
1053:Ohlone
1007:Sibley
870:Tilden
290:basalt
240:Moraga
223:Moraga
1129:Other
1058:Sunol
830:Garin
768:Parks
464:Notes
633:KQED
354:and
294:dike
238:and
126:1936
115:Area
221:to
1188::
689:^
672:^
656:.
631:.
620:^
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157:,
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577:.
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358:.
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
