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Neenach Volcano
Neenach Volcano is an extinct Miocene volcano in the Coastal Ranges of California. After formation, the volcanic field was split by a fault in the San Andreas Fault Zone, and over the last 23 million years, the two halves of the volcano have moved about 195 miles (314 kilometers) apart. The correlation of the two portions, now called the Pinnacles and Neenach volcanic formations, is significant; this correlation has become a “classic example” of plate tectonics for the scientific community. Ten rock types with nearly identical field, petrographic, and chemical characteristics are present in each formation in essentially the same stratigraphic order. This provides ample evidence for the correlation and interpreted movement along the San Andreas Fault. The volcano formed 23 million years ago during tectonic subduction of the oceanic Juan de Fuca Plate beneath the continental North American Plate, a process often associated with volcanic eruptions near the plate boundaries. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinnacles National Park Aerial
A pinnacle is an architectural Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and constructing buildings o ... element originally forming the cap or crown of a buttress or small Turret (architecture), turret, but afterwards used on parapets at the corners of towers and in many other situations. The pinnacle looks like a small spire. It was mainly used in Gothic architecture. The pinnacle had two purposes: # Ornamental – adding to the loftiness and verticity of the structure. They sometimes ended with statues, such as in Milan Cathedral. # Structural – the pinnacles were very heavy and often rectified with lead, in order to enable the flying buttresses to contain the stress of the structure vault (architecture), vaults and roof. This was done by adding compressive stress (a result of the pinnacle weight) t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breccia
Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of different origins, as indicated by the named types including sedimentary breccia, tectonic breccia, igneous breccia, impact breccia, and hydrothermal breccia. A megabreccia is a breccia composed of very large rock fragments, sometimes kilometers across, which can be formed by landslides, impact events, or caldera collapse. Types Breccia is composed of coarse rock fragments held together by cement or a fine-grained matrix. Like conglomerate, breccia contains at least 30 percent of gravel-sized particles (particles over 2mm in size), but it is distinguished from conglomerate because the rock fragments have sharp edges that have not been worn down. These indicate that the gravel was deposited very close to its source area, since otherwise th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanoes Of California
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 diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Crest Trail
The Pacific Crest Trail (PCT), officially designated as the Pacific Crest National Scenic Trail, is a long-distance hiking and equestrian trail closely aligned with the highest portion of the Cascade and Sierra Nevada mountain ranges, which lie east of the U.S. Pacific coast. The trail's southern terminus is next to the Mexico–United States border, just south of Campo, California, and its northern terminus is on the Canada–US border, upon which it continues unofficially to the Windy Joe Trail within Manning Park in British Columbia; it passes through the states of California, Oregon, and Washington. The Pacific Crest Trail is long and ranges in elevation from roughly above sea level near the Bridge of the Gods on the Oregon–Washington border to at Forester Pass in the Sierra Nevada. The route passes through 25 national forests and 7 national parks. Its midpoint is near Chester, California (near Mt. Lassen), where the Sierra and Cascade mountain ranges meet. It was d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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