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Table Mountain (Tuolumne County, California)
Table Mountain is a series of flat-topped hills in Tuolumne County, California that roughly parallels the modern Stanislaus River. These hills are capped by lava which flowed down from the crest of the Sierra Nevada 10.4 million years ago and hardened into a rock (latite) that is relatively resistant to erosion. The top of Table Mountain is composed of Table Mountain Latite, which formed from potassium-rich lavas erupted from a center of volcanism near modern-day Sonora Pass around 10.4 million years ago. Most outcrops on Table Mountain reveal flow-top breccias, while some outcrops show distinctive columnar jointing. Geology Initially, it was thought that Table Mountain had been formed by a dramatic inversion of the topography. This theory, first proposed in 1862 by William Brewer (a member of the Whitney Survey), suggested that the 10.4-million-year-old lava flow had followed the bottom of a bedrock valley cut by the ancestral Stanislaus River and then hardened, preserving the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sierra Nevada (U
The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily in Nevada. The Sierra Nevada is part of the American Cordillera, an almost continuous chain of mountain ranges that forms the western "backbone" of the Americas. The Sierra runs north-south and its width ranges from to across east–west. Notable features include General Sherman, the largest tree in the world by volume; Lake Tahoe, the largest alpine lake in North America; Mount Whitney at , the highest point in the contiguous United States; and Yosemite Valley sculpted by glaciers from one-hundred-million-year-old granite, containing high waterfalls. The Sierra is home to three national parks, twenty wilderness areas, and two national monuments. These areas include Yosemite, Sequoia, and Kings Canyon National Parks; and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphy
Stratigraphy is a branch of geology concerned with the study of rock layers ( strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostratigraphy (lithologic stratigraphy), biostratigraphy (biologic stratigraphy), and chronostratigraphy (stratigraphy by age). Historical development Catholic priest Nicholas Steno established the theoretical basis for stratigraphy when he introduced the law of superposition, the principle of original horizontality and the principle of lateral continuity in a 1669 work on the fossilization of organic remains in layers of sediment. The first practical large-scale application of stratigraphy was by William Smith in the 1790s and early 19th century. Known as the "Father of English geology", Smith recognized the significance of strata or rock layering and the importance of fossil markers for correlating strata; he created the first ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountains Of Tuolumne County, California
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher than a hill, typically rising at least 300 metres (1,000 feet) above the surrounding land. A few mountains are isolated summits, but most occur in mountain ranges. Mountains are formed through tectonic forces, erosion, or volcanism, which act on time scales of up to tens of millions of years. Once mountain building ceases, mountains are slowly leveled through the action of weathering, through slumping and other forms of mass wasting, as well as through erosion by rivers and glaciers. High elevations on mountains produce colder climates than at sea level at similar latitude. These colder climates strongly affect the ecosystems of mountains: different elevations have different plants and animals. Because of the less hospitable terrain and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inverted Relief
Inverted relief, inverted topography, or topographic inversion refers to landscape features that have reversed their elevation relative to other features. It most often occurs when low areas of a landscape become filled with lava or sediment that hardens into material that is more resistant to erosion than the material that surrounds it. ''Differential erosion'' then removes the less resistant surrounding material, leaving behind the younger resistant material, which may then appear as a ridge where previously there was a valley. Terms such as "inverted valley" or "inverted channel" are used to describe such features.Pain, C.F., and C.D. Ollier, 1995, ''Inversion of relief - a component of landscape evolution.'' Geomorphology. 12(2):151-165. Inverted relief has been observed on the surfaces of other planets as well as on Earth. For example, well-documented inverted topographies have been discovered on Mars.Pain, C.F., J.D.A. Clarke, and M. Thomas, 2007, ''Inversion of relief on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White-throated Swift
The white-throated swift (''Aeronautes saxatalis'') is a swift of the family Apodidae native to western North America, south to cordilleran western Honduras.Ryan TP, Collins CT. 2000. White-throated Swift (''Aeronautes saxatalis''). Version 2.0. In: Poole AF, Gill FB, editors. The Birds of North America nternet ited 2018 Oct 3 Ithaca (NY): Cornell Lab of Ornithology. . Its coastal range extends as far north as Northern California, while inland it has migratory populations found throughout the Great Basin and Rocky Mountain regions, ranging as far north as southern British Columbia. White-throated swifts are found in open areas near cliffs, rock faces, or man-made structures, where they roost. Swifts are social birds, and groups are often seen roosting and foraging for flying insects together. Description The white-throated swift is medium-sized bird that is primarily black and white. Its back and wings are blackish-brown or black, and its breast, belly, chin, and throat a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calochortus Luteus
''Calochortus luteus'', the yellow mariposa lily, is a mariposa lily endemic to California. Description The primarily bright deep yellow flower is 3–5 cm across and perianth bulb-shaped, lined red-brown inside, often also with central red-brown blotch and sparse hair inside. It is a perennial herb. Distribution This species is found on coastal prairie, grasslands and some open forest floors. Its range is along the coastal ranges from region to the northern Santa Barbara County Channel Islands and mainland, Northwestern California, the Sacramento Valley, and the Sierra Nevada foothills from there to the Tehachapi Mountains. Cultivation ''Calochortus luteus'' is used in landscape design, with ''"non-habitat sourced"'' bulbs available from native plant nurseries and societies, to grow as an ornamental plant in gardens and for restoration Restoration is the act of restoring something to its original state and may refer to: * Conservation and restoration of cultural herit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lupinus
''Lupinus'', commonly known as lupin, lupine, or regionally bluebonnet etc., is a genus of plants in the legume family Fabaceae. The genus includes over 199 species, with centers of diversity in North and South America. Smaller centers occur in North Africa and the Mediterranean. They are widely cultivated, both as a food source and as ornamental plants, but are invasive to some areas. Description The species are mostly herbaceous perennial plants tall, but some are annual plants and a few are shrubs up to tall. An exception is the ''chamis de monte'' ('' Lupinus jaimehintoniana'') of Oaxaca in Mexico, which is a tree up to tall. Lupins have soft green to grey-green leaves which may be coated in silvery hairs, often densely so. The leaf blades are usually palmately divided into five to 28 leaflets, or reduced to a single leaflet in a few species of the southeastern United States and eastern South America. The flowers are produced in dense or open whorls on an erect s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California Gold Rush
The California Gold Rush (1848–1855) was a gold rush that began on January 24, 1848, when gold was found by James W. Marshall at Sutter's Mill in Coloma, California. The news of gold brought approximately 300,000 people to California from the rest of the United States and abroad. The sudden influx of gold into the money supply reinvigorated the American economy; the sudden population increase allowed California to go rapidly to statehood, in the Compromise of 1850. The Gold Rush had severe effects on Native Californians and accelerated the Native American population's decline from disease, starvation and the California genocide. The effects of the Gold Rush were substantial. Whole indigenous societies were attacked and pushed off their lands by the gold-seekers, called "forty-niners" (referring to 1849, the peak year for Gold Rush immigration). Outside of California, the first to arrive were from Oregon, the Sandwich Islands (Hawaii) and Latin America in late 1848. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columnar Jointing
Columnar jointing is a geological structure where sets of intersecting closely spaced fractures, referred to as Joint (geology), joints, result in the formation of a regular array of polygonal Prism (geometry), prisms, or columns. Columnar jointing occurs in many types of igneous rocks and forms as the rock cools and contracts. Columnar jointing can occur in cooling lava flows and ashflow tuffs (ignimbrites), as well as in some shallow intrusions. Columnar jointing also occurs rarely in sedimentary rocks if they have been heated by nearby hot magma. The columns can vary from 3 meters to a few centimeters in diameter, and can be as much as 30 meters tall. They are typically parallel and straight, but can also be curved and vary in diameter. An array of regular, straight, and larger-diameter columns is called a colonnade; an irregular, less-straight, and smaller-diameter array is termed an entablature. The number of sides of the individual columns can vary from 3 to 8, with 6 sides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuolumne County, California
Tuolumne County (), officially the County of Tuolumne, is a county located in the U.S. state of California. As of the 2020 census, the population was 55,620. The county seat and only incorporated city is Sonora. Tuolumne County comprises the Sonora, CA Micropolitan Statistical Area. The county is in the Sierra Nevada region. The northern half of Yosemite National Park is located in the eastern part of the county. Etymology The name ''Tuolumne'' is of Native American origin and has been given different meanings, such as Many Stone Houses, The Land of Mountain Lions, and Straight Up Steep, the latter an interpretation of William Fuller, a native Chief. Mariano Vallejo, in his report to the first California State Legislature, said that the word is "a corruption of the Native American word ''talmalamne'' which signifies 'cluster of stone wigwams.'" The name may mean "people who dwell in stone houses," i.e., in caves. History Tuolumne County Boundaries One of Californi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breccias
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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
