Granite is a common type of felsic intrusive igneous rock, granular and phaneritic in texture. Granites can be predominantly white, pink, or gray depending on their mineralogy; the word "granite" comes from the Latin granum, a grain, in reference to the coarse-grained structure of such a holocrystalline rock. Speaking, granite is an igneous rock with between 20% and 60% quartz by volume, at least 35% of the total feldspar consisting of alkali feldspar, although the term "granite" is used to refer to a wider range of coarse-grained igneous rocks containing quartz and feldspar; the term "granitic" means granite-like and is applied to granite and a group of intrusive igneous rocks with similar textures and slight variations in composition and origin. These rocks consist of feldspar, quartz and amphibole minerals, which form an interlocking, somewhat equigranular matrix of feldspar and quartz with scattered darker biotite mica and amphibole peppering the lighter color minerals; some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic.
A granitic rock with a porphyritic texture is known as a granite porphyry. Granitoid is a descriptive field term for lighter-colored, coarse-grained igneous rocks. Petrographic examination is required for identification of specific types of granitoids; the extrusive igneous rock equivalent of granite is rhyolite. Granite is nearly always massive and tough; these properties have made granite a widespread construction stone throughout human history. The average density of granite is between 2.65 and 2.75 g/cm3, its compressive strength lies above 200 MPa, its viscosity near STP is 3–6·1019 Pa·s. The melting temperature of dry granite at ambient pressure is 1215–1260 °C. Granite has poor primary permeability overall, but strong secondary permeability through cracks and fractures if they are present. Granite is classified according to the QAPF diagram for coarse grained plutonic rocks and is named according to the percentage of quartz, alkali feldspar and plagioclase feldspar on the A-Q-P half of the diagram.
True granite contains both alkali feldspars. When a granitoid is devoid or nearly devoid of plagioclase, the rock is referred to as alkali feldspar granite; when a granitoid contains less than 10% orthoclase, it is called tonalite. A granite containing both muscovite and biotite micas is called two-mica granite. Two-mica granites are high in potassium and low in plagioclase, are S-type granites or A-type granites. A worldwide average of the chemical composition of granite, by weight percent, based on 2485 analyses: Granite containing rock is distributed throughout the continental crust. Much of it was intruded during the Precambrian age. Outcrops of granite tend to form rounded massifs. Granites sometimes occur in circular depressions surrounded by a range of hills, formed by the metamorphic aureole or hornfels. Granite occurs as small, less than 100 km2 stock masses and in batholiths that are associated with orogenic mountain ranges. Small dikes of granitic composition called aplites are associated with the margins of granitic intrusions.
In some locations coarse-grained pegmatite masses occur with granite. Granite is more common in continental crust than in oceanic crust, they are crystallized from felsic melts which are less dense than mafic rocks and thus tend to ascend toward the surface. In contrast, mafic rocks, either basalts or gabbros, once metamorphosed at eclogite facies, tend to sink into the mantle beneath the Moho. Granitoids have crystallized from felsic magmas that have compositions near a eutectic point. Magmas are composed of minerals in variable abundances. Traditionally, magmatic minerals are crystallized from the melts that have separated from their parental rocks and thus are evolved because of igneous differentiation. If a granite has a cooling process, it has the potential to form larger crystals. There are peritectic and residual minerals in granitic magmas. Peritectic minerals are generated through peritectic reactions, whereas residual minerals are inherited from parental rocks. In either case, magmas will evolve to the eutectic for crystallization upon cooling.
Anatectic melts are produced by peritectic reactions, but they are much less evolved than magmatic melts because they have not separated from their parental rocks. The composition of anatectic melts may change toward the magmatic melts through high-degree fractional crystallization. Fractional crystallisation serves to reduce a melt in iron, titanium and sodium, enrich the melt in potassium and silicon – alkali feldspar and quartz, are two of the defining constituents of granite; this process operates regardless of the origin of parental magmas to granites, regardless of their chemistry. The composition and origin of any magma that differentiates into granite leave certain petrological evidence as to what the granite's parental rock was; the final texture and composition of a granite are distinctive as to its parental rock. For instance, a granite, derived from partial melting of meta
Baja California Desert
The Baja California Desert is a desert ecoregion of Mexico's Baja California Peninsula. This ecoregion occupies the western portion of the Baja California peninsula, occupies most of the Mexican states of Baja California Sur and Baja California, it covers 77,700 square kilometers. The climate is dry, but the close proximity of the Pacific Ocean provides humidity and moderates the temperature; the flora consists of xeric shrubs and over 500 species of recorded vascular plants. The ecoregion includes most of the Peninsula's western slope, it is bounded on the west by the Pacific Ocean and on the east by the Peninsular Ranges and is centered on the coordinates 27.74°N 113.6°W / 27.74. North of 30° north latitude, the Baja California desert transitions to the California chaparral and woodlands; the southern tip of the peninsula lies within the San Lucan xeric scrub ecoregion. To the north are the Sierra Juárez and San Pedro Mártir pine-oak forests, where a number of tree species are found including the near-threatened California Fan Palm.
The climate is subtropical. Although rainfall is low, the Pacific Ocean provides some humidity and moderates the temperature compared to the Sonoran desert, which lies on the east slope of the Peninsular Ranges; the Baja California Desert ecoregion occurs on the western portion of the Baja California peninsula and occupies most of the Mexican states of Baja California Sur and Baja California. Elevation is variable, ranging from mountain ranges on the western central part, plains of median elevation, vast extensions of coastal dunes; the ecoregion is covered by xeric shrubs, which create varying associations based on elevation and soil conditions. The ecoregion has close to 500 species of vascular plants, of which a number are endemic, for example the Boojum tree or Creeping Devil. C. Michael Hogan. 2009. California Fan Palm: Washingtonia filifera, GlobalTwitcher.com, ed. Nicklas Stromberg Taylor H. Ricketts, Eric Dinerstein, David M. Olson, Colby J. Loucks, et al. 1999. Terrestrial Ecoregions of North America: a Conservation Assessment.
Island Press, Washington DC. "Baja California desert". Terrestrial Ecoregions. World Wildlife Fund
A summit is a point on a surface, higher in elevation than all points adjacent to it. The topographic terms acme, apex and zenith are synonymous; the term top is used only for a mountain peak, located at some distance from the nearest point of higher elevation. For example, a big massive rock next to the main summit of a mountain is not considered a summit. Summits near a higher peak, with some prominence or isolation, but not reaching a certain cutoff value for the quantities, are considered subsummits of the higher peak, are considered part of the same mountain. A pyramidal peak is an exaggerated form produced by ice erosion of a mountain top. Summit may refer to the highest point along a line, trail, or route; the highest summit in the world is Everest with height of 8844.43 m above sea level. The first official ascent was made by Sir Edmund Hillary, they reached the mountain`s peak in 1953. Whether a highest point is classified as a summit, a sub peak or a separate mountain is subjective; the UIAA definition of a peak is.
Otherwise, it's a subpeak. In many parts of the western United States, the term summit refers to the highest point along a road, highway, or railroad. For example, the highest point along Interstate 80 in California is referred to as Donner Summit and the highest point on Interstate 5 is Siskiyou Mountain Summit. A summit climbing differs from the common mountaineering. Summit expedition requires: 1+ year of training, a good physical shape, a special gear. Although a huge part of climber’s stuff can be left and taken at the base camps or given to porters, there is a long list of personal equipment. In addition to common mountaineers’ gear, Summit climbers need to take Diamox and bottles of oxygen. There are special requirements for crampons, ice axe, rappel device, etc. Geoid Hill – Landform that extends above the surrounding terrain Nadir Summit accordance Peak finder Summit Climbing Gear List
Sierra de la Giganta
The Sierra de la Giganta is a mountain range of eastern Baja California Sur state, located on the southern Baja California Peninsula in northwestern Mexico. It is a mountain range of the Peninsular Ranges System, which extends 1,500 km from Southern California, through the Baja California Peninsula in Baja California and Baja California Sur states; the Sierra de la Giganta extends along the southeastern Baja California Peninsula and close to the coast of the Gulf of California—Sea of Cortez. The highest point is Cerro de la Giganta at 3,858 feet in elevation, located near Loreto The range runs from Loreto in Loreto Municipality west of Loreto, southwards to La Paz Municipality northwest of La Paz. Natural historyThe xeric flora found in the Sierra de la Giganta is of the Baja California Desert ecoregion, of the Deserts and xeric shrublands Biome. Flora of Baja California Sur Peninsular Ranges topics Flickr photo set: Sierra de la Giganta
Southern California is a geographic and cultural region that comprises California's southernmost counties, is the second most populous urban agglomeration in the United States. The region is traditionally described as eight counties, based on demographics and economic ties: Imperial, Los Angeles, Riverside, San Bernardino, San Diego, Santa Barbara, Ventura; the more extensive 10-county definition, which includes Kern and San Luis Obispo counties, is used and is based on historical political divisions. The Colorado Desert and the Colorado River are located on southern California's eastern border with Arizona, the Mojave Desert is located north on California's Nevada border. Southern California's southern border is part of the Mexico–United States border. Southern California includes the built-up urban area which stretches along the Pacific coast from Ventura through Greater Los Angeles down to Greater San Diego, inland to the Inland Empire and Coachella Valley, it encompasses eight metropolitan areas, three of which together form the Greater Los Angeles Combined Statistical Area with over 18 million people, the second-biggest CSA after the New York CSA.
These three MSAs are: the Los Angeles metropolitan area, the Inland Empire (, the Oxnard–Thousand Oaks–Ventura metropolitan area. In addition, Southern California contains the San Diego metropolitan area with 3.3 million people, Bakersfield metro area with 0.9 million, the Santa Barbara, San Luis Obispo, El Centro metropolitan areas. The Southern California Megaregion is larger still, extending east into Las Vegas and south across the Mexican border into Tijuana. Within southern California are two major cities, Los Angeles and San Diego, as well as three of the country's largest metropolitan areas. With a population of 4,042,000, Los Angeles is the most populous city in California and the second most populous in the United States. South of Los Angeles and with a population of 1,307,402 is San Diego, the second most populous city in the state and the eighth most populous in the nation; the counties of Los Angeles, San Diego, San Bernardino, Riverside are the five most populous in the state, are in the top 15 most populous counties in the United States.
The motion picture and music industry are centered in the Los Angeles area in southern California. Hollywood, a district of Los Angeles, gives its name to the American motion picture industry, synonymous with the neighborhood name. Headquartered in southern California are The Walt Disney Company, Sony Pictures, Universal Pictures, MGM, Paramount Pictures, 20th Century Fox, Warner Bros. Universal, Warner Bros. and Sony run major record companies. Southern California is home to a large homegrown surf and skateboard culture. Companies such as Vans, Quiksilver, No Fear, RVCA, Body Glove are all headquartered here. Skateboarder Tony Hawk; some of the most famous surf locations are in southern California as well, including Trestles, The Wedge, Huntington Beach, Malibu. Some of the world's largest action sports events, including the X Games, Boost Mobile Pro, the U. S. Open of Surfing, are held in southern California; the region is important to the world of yachting with premier events including the annual Transpacific Yacht Race, or Transpac, from Los Angeles to Hawaii.
The San Diego Yacht Club held the America's Cup, the most prestigious prize in yachting, from 1988 to 1995 and hosted three America's Cup races during that time. The first modern era triathlon was held in Mission Bay, San Diego, California in 1974. Since southern California, San Diego in particular have become a mecca for triathlon and multi-sport racing and culture. Southern California is home to many sports sports networks such as Fox Sports Net. Many locals and tourists frequent the southern California coast for its beaches; the inland desert city of Palm Springs is popular. Southern California is not a formal geographic designation and definitions of what constitutes southern California vary. Geographically, California's North-South midway point lies at 37° 9' 58.23" latitude, around 11 miles south of San Jose. When the state is divided into two areas, the term southern California refers to the 10 southernmost counties of the state; this definition coincides neatly with the county lines at 35° 47′ 28″ North latitude, which form the northern borders of San Luis Obispo and San Bernardino counties.
Another definition for southern California uses Point Conception and the Tehachapi Mountains as the northern boundary. Though there is no official definition for the northern boundary of southern California, such a division has existed from the time when Mexico ruled California and political disputes raged between the Californios of Monterey in the upper part and Los Angeles in the lower part of Alta California. Following the acquisition of California by the United States, the division continued as part of the attempt by several pro-slavery politicians to arrange the division of Alta California at 36 degrees, 30 minutes, the line of the Missouri Compromise. Instead, the passing of the Compromise of 1850 enabled California to be a
San Jacinto Mountains
The San Jacinto Mountains are a mountain range in Riverside County, located east of Los Angeles in southern California in the United States. The mountains are named for one of the first Black Friars, Saint Hyacinth, popular patron in Latin America; the range extends for 30 mi from the San Bernardino Mountains southeast to the Santa Rosa Mountains. The San Jacinto Mountains are the northernmost of the Peninsular Ranges, which run 1,500 km from Southern California to the southern tip of the Baja California Peninsula; the highest peak in the range is San Jacinto Peak NAVD 88, the range is a Great Basin Divide landform for the Salton Watershed to the east.. The Coachella Valley stretches along the eastern side of the range, including the cities of Palm Springs and Rancho Mirage. San Gorgonio Pass separates the range from Mount San Gorgonio to the north; the western slope holds the community of Idyllwild. The range is the eastern boundary of location of Hemet. Much of the range is embraced by the Santa Rosa and San Jacinto Mountains National Monument created in 2000.
Mount San Jacinto State Park is located along the flank of San Jacinto Peak. Part of the eastern flank of the range is located within the Agua Caliente Indian Reservation. In 1990 the California Legislature created the Coachella Valley Mountains Conservancy to protect the mountains surrounding the valley; the range is a fault block of granitic rocks squeezed between the San Jacinto fault on the west and the San Andreas fault system on the east. The fault scarp on the northern and eastern side is one of the most abrupt in North America, going from sea level to 10,000 feet in a few miles; the height and steepness of the range points out that the San Jacinto fault and San Andreas fault are active and capable of producing major earthquakes. The last massive quake struck the southern segment of the San Andreas-San Jacinto fault complex more than 200 years ago making another major earthquake but not possible to predict. Rock slides from the range are possible during major earthquakes in the future, as they have been in the past.
These slides may impact the communities built directly adjacent to the steep escarpment on the desert side of the range. The San Jacinto Mountains, like the neighboring San Bernardino Mountains, are a humid island above the surrounding desert and semi-desert. Annual precipitation ranges from about 15 inches at the western base to as much as 30 inches above 5,500 feet; the coastal side of the range receives more precipitation than the eastern side. Most of the precipitation falls between November and March, with a secondary maximum associated with thunderstorms during the summer monsoon season between July and September; the precipitation totals are variable from year to year. Snow falls above 4,000 feet elevation in winter. Above 8,000 feet, snow sometimes persists until June. Near the crest, there are a few patches of snow that may persist all year in shady spots; the range can be thought of as a sky island, as it contains numerous species of flora and fauna that cannot tolerate the triple-digit-Fahrenheit heat of the surrounding valleys.
Vegetation found on the mountain flanks is influenced by elevation and climate. Near the valley floor, conditions are arid and hot, limiting the vegetative palette to species that are adapted to such conditions. At lower elevations forestation of the San Jacinto Mountains includes considerable California black oak associated with Coulter pine. At higher elevations, forests include Ponderosa pine, Jeffrey pine, Lodgepole pine, Incense cedar, White fir, Red fir, deciduous oak. There is a grove of over 150 Giant Sequoia Trees on the northeast facing slope; the sequoias were planted by the U. S. Forest Service in the 1970s, are now healthy and producing seedlings; as in many other western U. S areas, bark beetle infestations have caused loss of some of the forest trees in recent years during droughts. Wildfires have temporarily denuded some areas. Idyllwild, Pine Cove, Mountain Center, Pinyon Pines are located in the San Jacinto Mountains; the indigenous Cahuilla live in the deserts around the San Jacinto Mountains and used the range for hunting, to escape the summer heat.
The range was a frequent subject for Paul Grimm. Hollywood film directors have used the mountains to shoot film scenes. In Frank Capra's 1937 film, Lost Horizon, the Tahquitz Falls in Tahquitz Canyon was used as a scene. Today, the range is a destination for outdoor recreation; the Pacific Crest Trail runs along the spine of the range. A popular walking route runs from the Palm Springs Aerial Tramway Mountain Station above Palm Springs, to the high point of the range, with a mild climb of 2,400 ft compared to other routes with more elevation gain. Above Idyllwild is historic Tahquitz Peak and other rock climbing areas. Robinson, John W.. The San Jacintos: The Mountain Country from Banning to Borrego Valley. Arcadia, CA: Big Santa Ana Historical Society. P. 252. ISBN 0-9615421-6-0. BLM: Santa Rosa and San Jacinto Mountains National Monument