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Sonoma Volcanics
The Sonoma Volcanics are a geologic formation of volcanic origin that is widespread in Napa and Sonoma counties, California. Most of the formation is Pliocene in age and includes obsidian, perlitic glass, diatomaceous mud, pyroclastic tuff, pumice, rhyolite tuffs, andesite breccias and interbedded volcanic (basalt) lava flows. The formation serves as the parent material for many of the soils in the Napa and Sonoma wine regions. "The Sonoma volcanics underlie and form most of the mountain areas bordering the Napa and Sonoma Valleys except for small areas underlain by the older sedimentary and metamorphic rocks. A thick extensive body of tuffs and flows forms the Howell Mountains east of Napa and extends from Jamison Canyon northward into the area north of Mount St. Helena. The volcanic rocks crop out in a narrow, discontinuous strip along the west side of the alluvial plain of Napa Valley, and on that side also they extend northward to Mount St. Helena. They compose most of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroclastic Rock
Pyroclastic rocks (derived from the el, πῦρ, links=no, meaning fire; and , meaning broken) are clastic rocks composed of rock fragments produced and ejected by explosive volcanic eruptions. The individual rock fragments are known as pyroclasts. Pyroclastic rocks are a type of volcaniclastic deposit, which are deposits made predominantly of volcanic particles. 'Phreatic' pyroclastic deposits are a variety of pyroclastic rock that forms from volcanic steam explosions and they are entirely made of accidental clasts. 'Phreatomagmatic' pyroclastic deposits are formed from explosive interaction of magma with groundwater. Unconsolidated accumulations of pyroclasts are described as tephra. Tephra may become lithified to a pyroclastic rock by cementation or chemical reactions as the result of the passage of hot gases (fumarolic alteration) or groundwater (e.g. hydrothermal alteration and diagenesis) and burial, or, if it is emplaced at temperatures so hot that the soft glassy pyrocl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by Abraham Gottlob Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliocene California
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58See the 2014 version of the ICS geologic time scale million years ago. It is the second and most recent epoch of the Period in the . The Pliocene follows the Epoch and is followed by the |
Terranes
In geology, a terrane (; in full, a tectonostratigraphic terrane) is a crust fragment formed on a tectonic plate (or broken off from it) and accreted or " sutured" to crust lying on another plate. The crustal block or fragment preserves its own distinctive geologic history, which is different from that of the surrounding areas—hence the term "exotic" terrane. The suture zone between a terrane and the crust it attaches to is usually identifiable as a fault. A sedimentary deposit that buries the contact of the terrane with adjacent rock is called an overlap formation. An igneous intrusion that has intruded and obscured the contact of a terrane with adjacent rock is called a stitching pluton. Older usage of ''terrane'' simply described a series of related rock formations or an area having a preponderance of a particular rock or rock groups. Overview A tectonostratigraphic terrane is not necessarily an independent microplate in origin, since it may not contain the full thickness ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanism Of California
Volcanism, vulcanism or volcanicity is the phenomenon of eruption of molten rock (magma) onto the surface of the Earth or a solid-surface planet or moon, where lava, pyroclastics, and volcanic gases erupt through a break in the surface called a vent. It includes all phenomena resulting from and causing magma within the crust or mantle of the body, to rise through the crust and form volcanic rocks on the surface. Magmas, that reach the surface and solidify, form extrusive landforms. Volcanic processes Magma from the mantle or lower crust rises through the crust towards the surface. If magma reaches the surface, its behavior depends on the viscosity of the molten constituent rock. Viscous (thick) magma produces volcanoes characterised by explosive eruptions, while non-viscous (runny) magma produce volcanoes characterised by effusive eruptions pouring large amounts of lava onto the surface. In some cases, rising magma can cool and solidify without reaching the surface. Inste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonoma Mountains
The Sonoma Mountains are a northwest–southeast trending mountain range of the Inner Coast Ranges in the California Coast Ranges System, located in Sonoma County, Northern California. Geography The Sonoma Mountains range is approximately long. It separates the Sonoma Creek watershed from the Petaluma River and Tolay Creek watersheds. The highest point of this range is Sonoma Mountain, elevation . Jack London State Historic Park, Crane Creek Regional Park, and the Fairfield Osborn Preserve are both on Sonoma Mountain. A number of threatened and endangered species are found in the Sonoma Mountains including the fragrant fritillary (''Fritillaria liliacea''). Hydrology Many creeks rise in the Sonoma Mountains. From the northwestern slopes, Copeland Creek and Hinebaugh Creek flow to the Laguna de Santa Rosa, eventually entering the Pacific Ocean just south of Jenner, California. Matanzas Creek and Spring Creek flow north into Santa Rosa Creek, another tributary of the Laguna. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mayacamas Mountains
The Mayacamas Mountains are located in northwestern California in the United States. The mountain range is part of the Northern Inner Coast Ranges, of the California Coast Ranges System. Geography The Mayacamas Mountains are located south of the Mendocino Range, west of Clear Lake, and east of Ukiah in Mendocino and Lake Counties, and extend south into Napa and Sonoma Counties. The range stretches for in a northwest-southeasterly direction. Mountains in the range include: The range's highest point is Cobb Mountain, at in elevation, located in the central section. There are several other peaks over , including Mount Saint Helena and Hood Mountain. These peaks are sufficiently high to retain some snow cover in winter. Several streams rise in the Mayacamas Mountains including Mark West Creek, Sonoma Creek, Calabazas Creek, Arroyo Seco Creek, Putah Creek, and Santa Rosa Creek. ;Natural history Around ten million years ago, during pre-historic times (Miocene), the mountai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount St
Mount is often used as part of the name of specific mountains, e.g. Mount Everest. Mount or Mounts may also refer to: Places * Mount, Cornwall, a village in Warleggan parish, England * Mount, Perranzabuloe, a hamlet in Perranzabuloe parish, Cornwall, England * Mounts, Indiana, a community in Gibson County, Indiana, United States People * Mount (surname) * William L. Mounts (1862–1929), American lawyer and politician Computing and software * Mount (computing), the process of making a file system accessible * Mount (Unix), the utility in Unix-like operating systems which mounts file systems Displays and equipment * Mount, a fixed point for attaching equipment, such as a hardpoint on an airframe * Mounting board, in picture framing * Mount, a hanging scroll for mounting paintings * Mount, to display an item on a heavy backing such as foamcore, e.g.: ** To pin a biological specimen, on a heavy backing in a stretched stable position for ease of dissection or display ** To p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Howell Mountains
The Howell Mountains, which are also known as the Mt. George Range, are one of the California Coast Ranges. They divide the Suisun Valley on the east side, from Napa Valley on the west. Historically the southern part of the range has been referred to as both the Sierra de Suscol (Suscol Hills) and as the Sierra de Napa (Napa Hills). Geography The Howell Mountains begin at Sulphur Springs Mountain, near the towns of Vallejo and Benicia, and just north of the estuary where the Sacramento River flows into San Francisco Bay. The range then trends to the north and northwest for about to Howell Mountain, just northeast of St. Helena, California, where it merges with the Mayacamas Mountains. The Vaca Mountains, which are separated from the Howell Mountains by Suisun Valley on the east side, merge with the latter range northeast of St. Helena also. The crest of the range, which culminates at feet in the twin summit of Twin Sisters, represents the divide between the drainage of the Nap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonoma County Wine
Sonoma County wine is wine made in Sonoma County, California, in the United States. County names in the United States automatically qualify as legal appellations of origin for wine produced from grapes grown in that county and do not require registration with the United States Department of the Treasury, Alcohol and Tobacco Tax and Trade Bureau. Sonoma County is one of California's largest producers of wine grapes, far outproducing the Napa Valley AVA. History Grapes were planted in Sonoma County at Fort Ross as early as 1812. Padre Jose Altimira planted several thousand grape vines at Mission San Francisco Solano in what is now the city of Sonoma, in southern Sonoma County. Cuttings from the Sonoma mission vineyards were carried throughout the northern California area to start new vineyards. By the time of the Bear Flag Revolt in Sonoma and the subsequent annexation of California by the United States in 1854, wine grapes were an established part of agriculture in the re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Napa Valley
Napa Valley is an American Viticultural Area (AVA) located in Napa County in California's Wine Country. It was established by the Bureau of Alcohol, Tobacco and Firearms (ATF) on January 27, 1981. Napa Valley is considered one of the premier wine regions in the world. Records of commercial wine production in the region date back to the nineteenth century, but premium wine production dates back only to the 1960s. The combination of Mediterranean climate, geography and geology of the region are conducive to growing quality wine grapes. John Patchett established the Napa Valley's first commercial vineyard in 1858. In 1861 Charles Krug established another of Napa Valley's first commercial wineries in St. Helena. Viticulture in Napa suffered several setbacks in the late 19th and early 20th centuries, including an outbreak of the vine disease phylloxera, the institution of Prohibition, and the Great Depression. The wine industry in Napa Valley recovered, and helped by the results ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soils
Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former term specifically to displaced soil. Soil consists of a solid phase of minerals and organic matter (the soil matrix), as well as a porous phase that holds gases (the soil atmosphere) and water (the soil solution). Accordingly, soil is a three-state system of solids, liquids, and gases. Soil is a product of several factors: the influence of climate, relief (elevation, orientation, and slope of terrain), organisms, and the soil's parent materials (original minerals) interacting over time. It continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness, soil ecologists regard soil as an ecosystem. Most so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
